`[Federal Register Volume 89, Number 239 (Thursday, December 12, 2024)]
[Proposed Rules]
[Pages 100662-100716]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-28855]



[[Page 100661]]

Vol. 89

Thursday,

No. 239

December 12, 2024

Part III





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Threatened Species 
Status With Section 4(d) Rule for Monarch Butterfly and Designation of 
Critical Habitat; Proposed Rule

  Federal Register / Vol. 89, No. 239 / Thursday, December 12, 2024 / 
Proposed Rules  

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R3-ES-2024-0137; FXES1111090FEDR-256-FF09E21000]
RIN 1018-BE30


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status With Section 4(d) Rule for Monarch Butterfly and Designation of 
Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the monarch butterfly (Danaus plexippus), the iconic orange and 
black butterfly, as a threatened species and designate critical habitat 
under the Endangered Species Act of 1973, as amended (Act). We propose 
to list the monarch butterfly as a threatened species with protective 
regulations under section 4(d) of the Act (a ``4(d) rule''). Finalizing 
this rule as proposed would add this species to the List of Endangered 
and Threatened Wildlife and extend the Act's protections to the 
species. We also propose to designate critical habitat for the monarch 
butterfly under the Act. In total, approximately 4,395 acres (1,778 
hectares) in Alameda, Marin, Monterey, San Luis Obispo, Santa Barbara, 
Santa Cruz, and Ventura Counties, California, fall within the 
boundaries of the proposed critical habitat designation. We also 
announce the availability of an economic analysis of the proposed 
designation of critical habitat for the monarch butterfly. We also are 
notifying the public that we have scheduled two informational meetings 
followed by public hearings on the proposed rule.

DATES: We will accept comments received or postmarked on or before 
March 12, 2025. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. eastern time on the closing date.
    Public informational meetings and public hearings: We will hold two 
public informational meetings followed by public hearings. The first 
meeting and hearing will be from 6 p.m. to 8:30 p.m., eastern time, on 
January 14, 2025. To accommodate those in western time zones, the 
second meeting and hearing will be from 8 p.m. to 10:30 p.m., eastern 
time, on January 15, 2025.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R3-ES-2024-0137, 
which is the docket number for this rulemaking. Then, click on the 
Search button. On the resulting page, in the panel on the left side of 
the screen, under the Document Type heading, check the Proposed Rule 
box to locate this document. You may submit a comment by clicking on 
``Comment.''
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R3-ES-2024-0137, U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Information Requested, below, for more information).
    Availability of supporting materials: Supporting materials, such as 
the species status assessment report, are available at https://www.regulations.gov at Docket No. FWS-R3-ES-2024-0137. If we finalize 
the critical habitat designation, we will make the coordinates or plot 
points or both from which the maps are generated available at https://www.regulations.gov at Docket No. FWS-R3-ES-2024-0137.
    Public informational meeting and public hearing: The public 
informational meeting and the public hearing will be held virtually 
using the Zoom platform. See Public Hearing, below, for more 
information.

FOR FURTHER INFORMATION CONTACT: Barbara Hosler, Regional Listing 
Coordinator, U.S. Fish and Wildlife Service, Midwest Region 
Headquarters, 5600 American Blvd., Bloomington, MN 55437, telephone 
517-580-0254, email: [email protected]. Individuals in the United States 
who are deaf, deafblind, hard of hearing, or have a speech disability 
may dial 711 (TTY, TDD, or TeleBraille) to access telecommunications 
relay services. Individuals outside the United States should use the 
relay services offered within their country to make international calls 
to the point-of-contact in the United States. Please see Docket No. 
FWS-R3-ES-2024-0137 on https://www.regulations.gov for a document that 
summarizes this proposed rule.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species warrants 
listing if it meets the definition of an endangered species (in danger 
of extinction throughout all or a significant portion of its range) or 
a threatened species (likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range). If we determine that a species warrants listing, we must list 
the species promptly and designate the species' critical habitat to the 
maximum extent prudent and determinable. We have determined that the 
monarch butterfly meets the Act's definition of a threatened species; 
therefore, we are proposing to list it as such and proposing a 
designation of its critical habitat. Both listing a species as an 
endangered or threatened species and making a critical habitat 
designation can be completed only by issuing a rule through the 
Administrative Procedure Act rulemaking process (5 U.S.C. 551 et seq.).
    What this document does. We propose to add the monarch butterfly as 
a threatened species to the List of Endangered and Threatened Wildlife 
with protective regulations under section 4(d) of the Act, and we 
propose the designation of critical habitat for the species.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that the monarch butterfly 
meets the definition of a threatened species due to the following 
threats: the ongoing impacts from loss and degradation of breeding, 
migratory, and overwintering habitat (from past conversion of 
grasslands and shrublands to agriculture and widespread use of 
herbicides; logging/thinning at overwintering sites in Mexico; urban 
development, senescence (i.e., deterioration with age), and 
incompatible management of overwintering sites in California; and 
drought) (Factor A); exposure to insecticides (Factor E); and effects 
of climate change (Factor E).
    To improve future conditions so that the monarch migratory 
populations stabilize and grow, we need to (1)

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achieve a significant increase in the availability of milkweed and 
nectar plants in monarch breeding and migratory areas; (2) protect and 
enhance overwintering habitat; (3) avoid and minimize impacts to 
monarchs and their habitat from insecticides and herbicides; and (4) 
maintain public support for the conservation of monarch butterflies. 
Because of the monarch butterfly's general habitat use and wide 
distribution, all sectors of society, including the general public, 
have an opportunity to participate in a broad range of conservation 
efforts throughout the species' range.
    Section 4(a)(3) of the Act requires the Secretary of the Interior 
(Secretary), to the maximum extent prudent and determinable, 
concurrently with listing designate critical habitat for the species. 
Section 3(5)(A) of the Act defines critical habitat as (i) the specific 
areas within the geographical area occupied by the species, at the time 
it is listed, on which are found those physical or biological features 
(I) essential to the conservation of the species and (II) which may 
require special management considerations or protections; and (ii) 
specific areas outside the geographical area occupied by the species at 
the time it is listed, upon a determination by the Secretary that such 
areas are essential for the conservation of the species. Section 
4(b)(2) of the Act states that the Secretary must make the designation 
on the basis of the best scientific data available and after taking 
into consideration the economic impact, the impact on national 
security, and any other relevant impacts of specifying any particular 
area as critical habitat.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other governmental agencies, Native 
American Tribes, the scientific community, industry, or any other 
interested parties concerning this proposed rule. We particularly seek 
comments concerning:
    (1) The species' biology, range, and population trends, including:
    (a) Biological or ecological requirements of the species, including 
habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns, 
alternative migratory pathways, and the locations of any additional 
populations of this species;
    (d) Population dynamics and contributions from the nonmigratory 
populations, specifically resident monarchs in southern Florida, the 
Gulf Coast, the southern Atlantic Coast, and the southern Pacific 
Coast;
    (e) Historical and current population levels, and current and 
projected trends; and
    (f) Past and ongoing conservation measures for the species, its 
habitat, or both.
    (2) Threats and conservation actions affecting the species, 
including:
    (a) Factors that may be affecting the continued existence of the 
species, which may include habitat modification or destruction, 
overutilization, disease, predation, the inadequacy of existing 
regulatory mechanisms, or other natural or manmade factors;
    (b) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species;
    (c) Existing regulations or conservation actions that may be 
addressing threats to this species; and
    (d) Other potential threats that were not identified as key threats 
to the species.
    (3) Additional information concerning the historical and current 
status of this species.
    (4) Information to assist us with applying or issuing protective 
regulations under section 4(d) of the Act that may be necessary and 
advisable to provide for the conservation of the monarch butterfly. In 
particular, we seek information concerning:
    (a) The extent to which we should include any of the Act's section 
9 prohibitions in the 4(d) rule;
    (b) Whether we should consider any modifications or additional 
exceptions from the prohibitions in the 4(d) rule;
    (c) Whether the provisions related to the maintenance, enhancement, 
removal, or establishment of milkweed should be revised to include 
spatial or temporal restrictions or deferments;
    (d) Whether we should include an exception for the use of 
pesticides and, if so, what measures are reasonable, feasible, and 
adequate to reduce or offset pesticide exposure to monarchs from 
agricultural and non-agricultural uses (e.g., rangeland, rights-of-way, 
forestry, commercial areas, and mosquito control), including measures 
for specific classes of pesticides (e.g., herbicides, insecticides), 
pesticide uses, and application methods;
    (e) Whether we should include an exception for direct impacts from 
transportation and energy infrastructure, including mortality from 
collisions with wind turbines; and
    (f) Whether we could improve or modify our approach to the 4(d) 
rule in any way to provide for greater public participation and 
understanding, or to better accommodate public concerns and comments.
    (5) Specific information related to critical habitat, such as the 
following:
    (a) The amount and distribution of monarch butterfly habitat;
    (b) Any additional areas occurring within the range of the species 
in the United States, especially in breeding, migratory, or 
overwintering areas, that should be included in the critical habitat 
designation because they (i) are occupied at the time of listing and 
contain the physical or biological features that are essential to the 
conservation of the species and that may require special management 
considerations, or (ii) are unoccupied at the time of listing and are 
essential for the conservation of the species; and
    (c) Special management considerations or protection that may be 
needed in critical habitat areas we are proposing, including managing 
for the potential effects of climate change.
    (6) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat.
    (7) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation, and the related benefits of including or excluding 
specific areas.
    (8) Information on the extent to which the description of probable 
economic impacts in the economic analysis is a reasonable estimate of 
the likely economic impacts and any additional information regarding 
probable economic impacts that we should consider.
    (9) Whether any specific areas we are proposing for critical 
habitat designation should be considered for exclusion under section 
4(b)(2) of the Act, and whether the benefits of potentially excluding 
any specific area outweigh the benefits of including that area. If you 
think we should exclude any additional areas, please provide 
information supporting a benefit of exclusion.
    (10) Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to

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allow us to verify any scientific or commercial information you 
include.
    Please note that submissions merely stating support for, or 
opposition to, the action under consideration without providing 
supporting information, although noted, do not provide substantial 
information necessary to support a determination. Section 4(b)(1)(A) of 
the Act directs that determinations as to whether any species is an 
endangered or a threatened species must be made solely on the basis of 
the best scientific and commercial data available, and section 4(b)(2) 
of the Act directs that the Secretary shall designate critical habitat 
on the basis of the best scientific data available.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the website. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov.
    Our final determination may differ from this proposal because we 
will consider all comments we receive during the comment period as well 
as any information that may become available after this proposal. Based 
on the new information we receive (and, if relevant, any comments on 
that new information), we may conclude that the species is endangered 
instead of threatened, or we may conclude that the species does not 
warrant listing as either an endangered species or a threatened 
species. For critical habitat, our final designation may not include 
all areas proposed, may include some additional areas that meet the 
definition of critical habitat, or may exclude some areas if we find 
the benefits of exclusion outweigh the benefits of inclusion and 
exclusion will not result in the extinction of the species. In 
addition, we may change the parameters of the prohibitions or the 
exceptions to those prohibitions in the protective regulations issued 
or applied under section 4(d) of the Act if we conclude it is 
appropriate in light of comments and new information received. For 
example, we may expand the prohibitions if we conclude that the 
protective regulation as a whole, including those additional 
prohibitions, is necessary and advisable to provide for the 
conservation of the species. Conversely, we may establish additional or 
different exceptions to the prohibitions in the final rule if we 
conclude that the activities would facilitate or are compatible with 
the conservation and recovery of the species. In our final rule, we 
will clearly explain our rationale and the basis for our final 
decision, including why we made changes, if any, that differ from this 
proposal.

Public Hearing

    We have scheduled two public informational meetings with public 
hearings on this proposed rule for the monarch butterfly. We will hold 
the public informational meetings and public hearings on the dates and 
times listed above under Public informational meeting and public 
hearing in DATES. We are holding the public informational meetings and 
public hearings via the Zoom online video platform and via 
teleconference so participants can attend remotely. For security 
purposes, registration is required. To listen and view a meeting and 
hearing via Zoom, listen to a meeting and hearing by telephone, or 
provide oral public comments at a public hearing by Zoom or telephone, 
you must register. For information on how to register, or if you 
encounter problems joining Zoom the day of the meeting, visit https://www.fws.gov/species/monarch-danaus-plexippus. Registrants will receive 
the Zoom link and the telephone number for the public informational 
meeting and public hearing for which they have registered. If 
applicable, interested members of the public not familiar with the Zoom 
platform should view the Zoom video tutorials (https://support.zoom.us/hc/en-us/articles/206618765-Zoom-video-tutorials) prior to the public 
informational meetings and public hearings.
    The public hearings will provide interested parties an opportunity 
to present verbal testimony (formal, oral comments) regarding this 
proposed rule. While the public informational meetings will be 
opportunities for dialogue with the Service, the public hearings are 
not: They are forums for accepting formal verbal testimony. In the 
event there is a large attendance, the time allotted for oral 
statements may be limited. Therefore, anyone wishing to make an oral 
statement at a public hearing for the record is encouraged to provide a 
prepared written copy of their statement to us through the Federal 
eRulemaking Portal, or U.S. mail (see ADDRESSES, above). There are no 
limits on the length of written comments submitted to us. Anyone 
wishing to make an oral statement at a public hearing must register 
before the hearing https://www.fws.gov/species/monarch-danaus-plexippus. The use of a virtual public hearing is consistent with our 
regulations at 50 CFR 424.16(c)(3).

Previous Federal Actions

    On August 26, 2014, we received a petition from the Center for 
Biological Diversity, Center for Food Safety, Xerces Society for 
Invertebrate Conservation, and Dr. Lincoln Brower, requesting that we 
list the monarch butterfly as a threatened species under the Act. On 
December 31, 2014, we published a 90-day finding that the petition 
presented substantial scientific or commercial information, indicating 
that listing the monarch butterfly may be warranted (79 FR 78775). On 
December 17, 2020, we published a 12-month finding that listing the 
species as an endangered or threatened species is warranted but 
precluded by higher priority actions (85 FR 81813). The species 
remained so designated in the annual candidate notices of review on May 
3, 2022 (87 FR 26152), and June 27, 2023 (88 FR 41560).

Peer Review

    A species status assessment (SSA) team prepared an SSA report for 
the monarch butterfly. The SSA team was composed of Service biologists, 
in consultation with other species experts. The SSA report represents a 
compilation of the best scientific and commercial data available 
concerning the status of the species, including the impacts of past, 
present, and future factors (both negative and beneficial) affecting 
the species.
    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 
2016, memorandum updating and clarifying the role of peer review in 
listing actions under the Act (https://www.fws.gov/sites/default/files/documents/peer-review-policy-directors-memo-2016-08-22.pdf), we 
solicited independent scientific review of the information contained in 
the monarch butterfly SSA report. In 2018, we sent the first version 
(1.0) of the SSA report to 6 independent peer reviewers and received 5 
responses. In 2020, we sent the second version (2.0) of the SSA report 
to 3 peer reviewers and received 2 responses. In 2023, we sent the SSA

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report version 2.2 to 13 peer reviewers and received 7 responses. No 
individual peer reviewed the SSA report more than once. Results of this 
structured peer review process can be found at https://www.regulations.gov. In preparing this proposed rule, we incorporated 
the results of these reviews, as appropriate, into the SSA report, 
which is the foundation for this proposed rule.

Summary of Peer Reviewer Comments

    As discussed in Peer Review above, we received comments from 14 
total peer reviewers on the draft SSA report. We reviewed all comments 
we received from the peer reviewers for substantive issues and new 
information regarding the contents of the SSA report. The peer 
reviewers provided additional references, clarifications, and 
suggestions.
    We updated the SSA report based on these peer reviewers' comments, 
including restructuring several sections within the report, revising 
our description of adaptive capacity, clarifying specific points and 
terminology where appropriate, and adding additional details and 
suggested references when needed. Additional peer reviewer comments are 
addressed in the following summary, as well as throughout the Summary 
of Biological Status and Threats, below, and were incorporated into the 
SSA report as appropriate (Service 2024a, entire).
    Comment 1: Two reviewers asked us to elaborate on whether our 
assessment of resilience or the extinction threshold for western 
migratory monarchs should change based on a few years of numbers that 
have bounced back above 200,000 after the low of less than 2,000 
individuals in the winter of 2019-2020.
    Our response: It is plausible that migratory monarchs experienced 
good weather that resulted in abundant and well-timed milkweed and 
nectar resources across their breeding habitat in western North America 
in 2021, which provided for a significant increase in the overwintering 
count from below 2,000 individuals in 2019-2020. With only a few years 
of improved population numbers, we are currently unable to determine 
whether the western migratory population's status is improving or if 
these data support the continuation of its fluctuation and decline. 
While this does not change our current assessment of the population's 
resilience, we have added text clarifying this uncertainty to our SSA 
report to further address this comment.
    We also revisited our extinction thresholds in western North 
America. In the model presented in our SSA, we use a range of 
extinction thresholds, which are informed by scientific literature 
(i.e., Schultz et al. 2017, entire; Wells et al. 1990, p. 124). With 
the observed western population rebound, these estimates may be 
conservative. While the extinction thresholds we used are currently the 
best available, some uncertainty remains about the size of extinction 
thresholds and the time lag necessary to confirm assumptions about 
population stability or extinction trajectories. Therefore, we could be 
either overestimating or underestimating extinction risk depending on 
the accuracy of the thresholds.
    Comment 2: One reviewer questioned our reliance on overwintering 
counts to inform our understanding of eastern North American monarch 
butterfly population trends, in contrast to using surveys at other 
locations and at other times during the year.
    Our response: Monitoring at overwintering sites allows for the most 
practical and direct assessment of annual population levels, where the 
near-entirety of the migratory population can be evaluated consistently 
and comprehensively, reflecting the full range of threats and 
population dynamics encountered over the prior annual breeding and 
migration cycle. The question about the optimal approach for annual 
census of monarch butterfly populations (e.g., overwintering data v. 
non-overwintering data) has been addressed in a more recent review of 
the methodology, which concluded that the overwintering area of the 
eastern North American population is an accurate representation of the 
size of the population (Pleasants et al. 2024, p. 62). Our analysis of 
this topic based on the preponderance of scientific evidence is 
incorporated into the most recent version of the SSA report (Service 
2024a, pp. 70-76).
    Comment 3: Two reviewers noted that the decline of the eastern 
North American monarchs may have slowed or stabilized for the past 
decade or more, potentially due to an associated slowing or plateau of 
habitat loss. With this potential slowing or stabilization, one of 
these reviewers asked if the extinction risk may have thus decreased. 
They also noted differences in population decline based on the modeling 
assumption of density-dependence or independence.
    Our response: The estimates of population viability (and extinction 
risk) presented in the SSA report are based on the overall population 
trajectory (growth rate), along with the current population size and 
the fluctuations exhibited year-to-year. Growth rate and variability 
are derived using time series data, which may be influenced by the 
number of years being analyzed.
    Different analyses have explored the possibility that past declines 
in milkweed, or habitat more generally, alongside the expansion of 
genetically modified crops and associated herbicides and pesticides, 
may have effectively plateaued in recent years. Some evidence has 
emerged of a change in trajectory for the eastern population since 
2014, but as of 2020, statistical support for such a change was 
insufficient (Thogmartin et al. 2020, entire). More recently, an 
analysis of overwintering data for the eastern population estimated a 
median annual rate of growth of 0.93 (0.67-1.30, 95-percent confidence 
interval (CI)). These results indicate that the population is 
declining, even when assuming relatively stable land use and landcover 
change relative to the conditions that had driven steeper population 
declines in previous decades (Thogmartin 2024, entire).
    Other published analyses estimate monarch population growth rates 
and persistence/extinction risks using alternative models and different 
data sets. These include non-overwintering population data, different 
time-series of annual population estimates, different modeling 
assumptions about density-dependence, and different relationships 
between population size and growth (i.e., increased density of monarchs 
will result in decreased population growth and decreased density of 
monarchs will result in increased population growth). One recent 
analysis (Meehan and Crossley 2023, entire) used a variable change 
model to characterize the trend in eastern North American monarch 
abundance, suggesting that the monarch population has rebounded after a 
period of decline, thereby leading to a markedly lower risk of 
extinction relative to other assessments (e.g., Semmens et al. 2016, 
entire; Schultz et al. 2017, entire; Thogmartin 2024, entire), 
including our SSA analyses. Meehan and Crossley (2023, entire) assume 
density dependence, which constrains the uncertainty associated with 
the predicted abundance estimates (small populations recover faster 
under density-dependent assumptions than density-independent 
assumptions). Though their density dependent model provides a good fit 
for the 10-year dataset they analyzed, the models cannot identify the 
mechanism behind the apparent decline in growth rate as populations 
increase. The assessment by Meehan and Crossley (2023, entire) did not 
incorporate the impacts of changing future conditions.

[[Page 100666]]

    Another analysis that also did not incorporate the impacts of 
changing future conditions assumes the variability in the population 
numbers is now driven by environmental and demographic stochasticity 
(Thogmartin 2024, entire). This approach is more conservative because 
it results in increased variability at small populations sizes, as 
compared to the assumption of density dependence (which assumes 
increased per capita growth when populations are small). In this 
modeling approach, when population abundance has been reduced to a low 
level, demographic and environmental stochasticity alone (and not 
necessarily a declining trend) are now the driving factors, resulting 
in an increased risk of extinction. After careful examination, our 
estimates in the SSA for the annual rate of growth, population 
viability, and extinction risk continue to be in line with the best 
available information.
    Comment 4: One reviewer of a later version of the SSA asked for 
additional clarification on why the model for monarch butterfly 
extinction was not re-run with updated data that had been collected 
since the first version of the SSA.
    Our response: Based on our previous sensitivity testing of the 
model presented in the SSA, updated values would not significantly 
change the output and results, and thus would not change the outcomes 
in our report. Therefore, instead of rerunning the model, we instead 
prioritized evaluating new literature and information that might have 
changed the SSA analyses and conclusions. We provide further 
clarification and explanation in the updated SSA report (Service 2024a, 
p. 149).
    Comment 5: One reviewer commented that nonmigratory monarch 
butterflies might persist, even if the migratory monarchs were to 
become extirpated. The reviewer also suggested that one potential 
reason for the declines in migratory individuals in the West could be 
due to a shift to more individuals existing in nonmigratory populations 
during winter.
    Our response: According to recent research, the resident 
(nonmigratory) population in California is not sufficient to make up 
for the loss of the migratory population in western North America; 
there are still orders of magnitude fewer butterflies now than in the 
recent past (Crone and Schultz 2021, p. 1535). Also, the resident 
population probably lacks the demographic capacity to expand its range 
inland during summer months. Resident populations of monarch 
butterflies build up high levels of a protozoan parasite, Ophryocystis 
elektroscirrha (OE), at least in part due to the absence of migratory 
culling and migratory escape (Satterfield et al. 2015, pp. 4-5). In 
California, about 8 percent of migratory monarch butterflies are 
infected with OE, compared to about 75 percent of residents 
(Satterfield et al. 2016, p. 346). Similarly, for the eastern North 
American population, less than 10 percent of migratory monarch 
butterflies are infected with OE, compared to 75-100 percent of 
nonmigratory monarchs in Florida (Altizer and de Roode 2015, p. 91). 
OE-infected monarch butterflies experience lower survival, lower egg-
laying rates, and produce about 0.8 adult daughters per female (Crone 
and Schultz 2021, Supplement S4). This rate of increase is enough for 
resident monarch butterfly populations to persist in urban areas, but 
it does not provide the ability to rapidly colonize the other Western 
States (Crone and Schultz 2021, p. 1536). We acknowledge alternative 
overwintering strategies, including nonmigratory monarchs, in the 
uncertainties section of the SSA report (Service 2024a, pp. 70-76).

I. Proposed Listing Determination

Background

    A thorough review of the taxonomy, life history, and ecology of the 
monarch butterfly (Danaus plexippus; referred to as ``monarch'' or 
``monarch butterfly'' herein) is presented in the SSA report version 
2.3 (Service 2024a, entire).
    The monarch is a brightly colored butterfly species, native to 
North America, with a range that has expanded west via human assistance 
to many islands in the Pacific Ocean and to the east to the Iberian 
Peninsula to now occupy 90 countries, islands, and island groups. 
Despite the expansion, over 90 percent of monarchs worldwide continue 
to live and migrate in their native range in North America. The species 
requires habitat with milkweed (genus Asclepias or closely related 
genera) as a larval host plant and floral nectar sources for adults. 
Migratory monarchs in North America also use overwintering habitat, 
where the adults cluster on trees.
    Adult monarch butterflies are large and conspicuous, with bright-
orange wings surrounded by a black border and covered with black veins. 
The black border has a double row of white spots, present on the upper 
side and lower side of forewings and hindwings (Bouseman and Sternburg 
2001, p. 222). Adult monarchs are sexually dimorphic, with males having 
narrower wing venation and scent patches (Commission for Environmental 
Cooperation (CEC) 2008, p. 11). The monarch butterfly has bright and 
contrasting coloration, which serves as a warning to predators that 
eating them can be toxic.
    The migratory North American populations are located east and west 
of the Rocky Mountains and overwinter primarily at sites with specific 
microhabitats in central Mexico and California, respectively. In 
central Mexico, the species primarily overwinters in mountainous 
regions where the monarchs form dense clusters mainly on oyamel fir 
trees (Abies religiosa). Western monarchs spend the fall and winter at 
tree groves along the California coast, northern Baja California, 
Mexico, and at a few inland sites in the Saline Valley of California. 
These groves are populated by a variety of tree species, including blue 
gum eucalyptus (Eucalyptus globulus), Monterey pine (Pinus radiata), 
Monterey cypress (Cupressus macrocarpa), and others. The overwintering 
sites for both the eastern and western North American migratory monarch 
populations provide protection from the elements and a microhabitat 
conducive for winter survival. In contrast, monarchs in habitats with 
suitable winter climates (e.g., some areas in California and Florida) 
may breed year-round without migrating.
    During the breeding season for monarchs, adults lay their eggs on 
milkweed, and larvae emerge after 2 to 5 days (Zalucki 1982, p. 242; 
CEC 2008, p. 12). Larvae develop through five larval instars (intervals 
between molts) over a period of 9 to 18 days, feeding on milkweed and 
sequestering toxic cardenolides as a defense against predators (Parsons 
1965, p. 299). The larva then pupates into a chrysalis before eclosing 
6 to 14 days later as an adult butterfly. Monarchs produce multiple 
generations during the breeding season, with most adult butterflies 
living approximately 2 to 5 weeks; however, migrating and overwintering 
adults enter into reproductive diapause (suspended reproduction) and 
live 6 to 9 months (Cockrell et al. 1993, pp. 245-246; Herman and Tatar 
2001, p. 2509).

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and the implementing 
regulations in title 50 of the Code of Federal Regulations (CFR) set 
forth the procedures for determining whether a species is an endangered 
species or a threatened species, issuing protective

[[Page 100667]]

regulations for threatened species, and designating critical habitat 
for endangered and threatened species.
    The Act defines an ``endangered species'' as a species that is in 
danger of extinction throughout all or a significant portion of its 
range, and a ``threatened species'' as a species that is likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range. The Act requires that we 
determine whether any species is an endangered species or a threatened 
species because of any of the following factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the species' expected response and 
the effects of the threats--in light of those actions and conditions 
that will ameliorate the threats--on an individual, population, and 
species level. We evaluate each threat and its expected effects on the 
species, then analyze the cumulative effect of all of the threats on 
the species as a whole. We also consider the cumulative effect of the 
threats in light of those actions and conditions that will have 
positive effects on the species, such as any existing regulatory 
mechanisms or conservation efforts. The Secretary determines whether 
the species meets the definition of an ``endangered species'' or a 
``threatened species'' only after conducting this cumulative analysis 
and describing the expected effect on the species.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis, which is 
further described in the 2009 Memorandum Opinion on the foreseeable 
future from the Department of the Interior, Office of the Solicitor (M-
37021, January 16, 2009; ``M-Opinion,'' available online at https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf). 
The foreseeable future extends as far into the future as the U.S. Fish 
and Wildlife Service and National Marine Fisheries Service (hereafter, 
the Services) can make reasonably reliable predictions about the 
threats to the species and the species' responses to those threats. We 
need not identify the foreseeable future in terms of a specific period 
of time. We will describe the foreseeable future on a case-by-case 
basis, using the best available data and taking into account 
considerations such as the species' life-history characteristics, 
threat projection timeframes, and environmental variability. In other 
words, the foreseeable future is the period of time over which we can 
make reasonably reliable predictions. ``Reliable'' does not mean 
``certain''; it means sufficient to provide a reasonable degree of 
confidence in the prediction, in light of the conservation purposes of 
the Act.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
threats to the species. The SSA report does not represent our decision 
on whether the species should be proposed for listing as an endangered 
or threatened species under the Act. However, it does provide the 
scientific basis that informs our regulatory decisions, which involve 
the further application of standards within the Act and its 
implementing regulations and policies.
    To assess monarch butterfly viability, we used the three 
conservation biology principles of resiliency, redundancy, and 
representation (Shaffer and Stein 2000, pp. 306-310). Briefly, 
resiliency is the ability of the species to withstand environmental and 
demographic stochasticity (for example, wet or dry, warm or cold 
years); redundancy is the ability of the species to withstand 
catastrophic events (for example, droughts, large pollution events); 
and representation is the ability of the species to adapt to both near-
term and long-term changes in its physical and biological environment 
(for example, climate conditions, pathogens). In general, species 
viability will increase with increases in resiliency, redundancy, and 
representation (Smith et al. 2018, p. 306). Using these principles, we 
identified the species' ecological requirements for survival and 
reproduction at the individual, population, and species levels, and 
described the beneficial and risk factors influencing the species' 
viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical 
and current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. Throughout all of these 
stages, we used the best available information to characterize 
viability as the ability of a species to sustain populations in the 
wild over time, which we then used to inform our regulatory decision.
    The following is a summary of the key results and conclusions from 
the SSA report; the full SSA report can be found at Docket FWS-R3-ES-
2024-0137 on https://www.regulations.gov.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of the 
species and its resources, and the threats that influence the species' 
current and future condition, in order to assess the species' overall 
viability and the risks to that viability.

Species Needs

Individual-Level Ecology
    The monarch life cycle varies by geographic location. Migratory 
monarchs in North America are the

[[Page 100668]]

ancestral population for all other monarch populations (Pierce et al. 
2014, p. 4; Zhan et al. 2014, p. 318; Hemstrom et al. 2022, pp. 4551-
4552), which dispersed from North America via human assistance, 
potentially aided through wind dispersal events (Brower 1995, p. 354), 
and now occur in Central and South America; Australia; New Zealand; 
islands of the Pacific and Caribbean, and elsewhere (Malcolm and 
Zalucki 1993, pp. 3-5) where milkweed (their larval host plant) was 
already present or introduced. In a few parts of North America (such as 
parts of Florida, the Gulf Coast, and California) and in most areas 
outside North America, monarchs breed year-round, repeatedly following 
the above-referenced life cycle throughout the year. However, monarchs 
in temperate climates such as eastern and western North America undergo 
long-distance migration, where the migratory generation of adults is in 
reproductive diapause and lives for an extended period of time (Herman 
and Tatar 2001, p. 2509).
    In the fall, in both eastern and western North America, monarchs 
begin migrating to their respective overwintering sites. This migration 
can take monarchs distances of over 2,000 miles (mi) (3,000 kilometers 
(km)) (Urquhart and Urquhart 1978, p. 1760) and last for over 2 months 
(Brower 1996, p. 93). The vast majority of migratory individuals in 
eastern North America fly south or southwest to mountainous 
overwintering grounds in central Mexico, although some minor 
alternative migratory routes have also been suggested (Dockx et al. 
2023, p. 314). Migratory individuals in western North America generally 
fly shorter distances south and west to overwintering groves along the 
California coast into northern Baja California (Solensky 2004, p. 79). 
Data from monarchs tagged in the southwestern States in the fall 
suggest that those in Nevada migrate to California, those in New Mexico 
migrate to Mexico, and those in Arizona migrate to either Mexico or 
California (Southwest Monarch Study Inc. 2018, unpaginated). In early 
spring (February-March), surviving monarchs break diapause and mate at 
the overwintering sites before dispersing (Leong et al. 1995, p. 46; 
van Hook 1996, pp. 16-17). The same individuals that undertook the 
initial southward migration begin flying back through the breeding 
grounds, and their offspring start the cycle of generational migration 
over again (Malcolm et al. 1993, p. 262).
    The spring monarch migrations in eastern and western North America 
represent massive annual range expansions. In eastern North America, 
monarchs travel north in the spring, from Mexico to Canada, over two to 
three successive generations, breeding along the way (Flockhart et al. 
2013, pp. 4-5). Individual monarchs may disperse as far north as they 
can physiologically tolerate based on climatic conditions and available 
vegetation; the most specific predictors of the northern distribution 
of individual monarchs are monthly mean temperature and precipitation 
(Flockhart et al. 2013, p. 4; Flockhart et al. 2017, p. 2570). The 
number of generations of monarchs produced in a given year in a 
migratory population can vary between three and five and is dependent 
upon environmental conditions (Brower 1996, p. 100). While a majority 
of the eastern monarchs shift to the more northern reaches of their 
range, western monarchs continue to occupy and breed in warmer climates 
throughout the summer, while also expanding to include the farther 
reaches of their range. In the spring in western North America, 
monarchs migrate north and east over multiple generations from coastal 
California toward the Rockies and to the Pacific Northwest (Urquhart 
and Urquhart 1977, p. 1585; Nagano et al. 1993, entire). In the 
southwestern States, migrating monarchs tend to occur more frequently 
near water sources such as rivers, creeks, roadside ditches, and 
irrigated gardens (Morris et al. 2015, p. 100).
    In addition to the monarchs that overwinter by clustering at known 
overwintering roost sites, some monarchs in North America also breed 
year-round or breed throughout the winter. These individuals require 
the breeding habitat and suitable climate (table 1) and are discussed 
further in Species-Level Ecology, below.
    To facilitate the massive annual spring range expansion, adult 
monarch butterflies require a diversity of blooming nectar resources, 
which they feed on both throughout their migration routes and in their 
breeding grounds (spring through fall). Monarchs also need milkweed 
(for both oviposition and larval feeding) embedded within this diverse 
nectaring habitat. The correct phenology, or timing, of both monarchs 
and nectar plants and milkweed is important for monarch survival. The 
position of these resources on the landscape is important as well (see 
Population-Level Ecology, below). In western North America, nectar and 
milkweed resources are often associated with riparian corridors, and 
milkweed may function as the principal nectar source for monarchs in 
more arid regions (Dingle et al. 2005, p. 494; Pelton et al. 2018, p. 
18; Waterbury and Potter 2018, p. 38; Dilts et al. 2018, p. 8). 
Individuals need nectar and milkweed resources year-round in 
nonmigratory populations. Additionally, many monarchs use a variety of 
roosting trees along the fall migration route (table 1).
    Migratory individuals of eastern and western North America require 
a specific microclimate at overwintering sites. The eastern population 
of monarchs overwinter in Mexico, where this microclimate is provided 
by forests primarily composed of oyamel fir trees, on which the 
monarchs form dense clusters (Williams and Brower 2015, pp. 109-110). 
These cluster formations provide a buffer for individuals against 
freezing temperatures, lipid depletion, and desiccation (Brower et al. 
2008, p. 186). The sites used for overwintering primarily occur in 
mountainous areas west of Mexico City located between elevations of 
9,500 feet (ft) (2,900 meters (m)) and 10,800 ft (3,300 m) (Slayback 
and Brower 2007, p. 147). The temperature must remain cool enough to 
prevent excessive lipid depletion (Alonso-Mej[iacute]a et al. 1997, p. 
935), while at the same time staying warm enough to prevent freezing 
(Anderson and Brower 1996, pp. 111-113). Exposure to these cooler 
temperatures also helps orient the monarchs northward in the spring 
(Guerra and Reppert 2013, pp. 421-422). The oyamel fir forest provides 
essential protection from the elements, including rain, snow, wind, 
hail, and excessive solar radiation (Williams and Brower 2015, p. 109). 
Many sites also provide a source of hydration via nectar plants or a 
water source (Brower et al. 1977, pp. 237-238). Most of the observed 
overwintering sites are located within the Monarch Butterfly Biosphere 
Reserve, which covers more than 138,000 acres (ac) (56,000 hectares 
(ha)) (Vidal and Rend[oacute]n-Salinas 2014, p. 169; Ram[iacute]rez et 
al. 2015, p. 158).
    Migratory monarchs in the western population primarily overwinter 
in groves along the coast of California and Baja California (Jepsen and 
Black 2015, p. 149). The location and structure of these sites provide 
the specific microclimate (although different from the Mexico 
overwintering microclimate) needed for survival in the western 
overwintering areas. Approximately 400 groves have been known to be 
occupied, but only a portion of these sites is occupied in any given 
year. These sites, typically close to the coast, span approximately 761 
mi (1,225 km) of coastline (COSEWIC 2010, p. 10). These groves are 
populated by a variety of tree species, including blue gum eucalyptus, 
Monterey pine, and Monterey cypress

[[Page 100669]]

(Griffiths and Villablanca 2015, pp. 41, 46-47), all of which act as 
roost trees. These groves provide indirect sunlight for the 
overwintering monarchs, sources of moisture for hydration, defense 
against freezing temperatures, and protection against strong winds 
(Tuskes and Brower 1978, p. 149; Leong 1990, pp. 908-910, Leong 1999, 
p. 213). The close proximity to the coast (average distance of 1.47 mi 
(2.37 km)) also provides a mild winter climate (Leong et al. 2004, p. 
180).

                   Table 1--Individual-Level Requisites for Monarch Survival and Reproduction
----------------------------------------------------------------------------------------------------------------
               Life stage                         Requirements                        Description
----------------------------------------------------------------------------------------------------------------
Egg, larva, and adult--breeding.........  Milkweed resources.........  Healthy and abundant milkweed is needed
                                                                        for oviposition and larval consumption.
Adult--breeding and migration...........  Nectar resources...........  Sufficient quality and quantity of nectar
                                                                        from flowers is needed for adult feeding
                                                                        throughout the breeding and migration
                                                                        seasons.
Adult--overwintering....................  Suitable habitat for         Habitat that provides a specific roosting
                                           overwintering.               microclimate for overwintering:
                                                                        protection from the elements (e.g.,
                                                                        rain, wind, hail, excessive radiation)
                                                                        and moderate temperatures that are warm
                                                                        enough to prevent freezing yet cool
                                                                        enough to prevent lipid depletion.
                                                                        Nectar and clean water sources located
                                                                        near roosting sites.
Adult--migration........................  Connectivity and phenology.  Nectar and milkweed resources along the
                                                                        migration route when butterflies are
                                                                        present; the size and spatial
                                                                        arrangement of habitat patches are
                                                                        generally thought to be important
                                                                        aspects, but currently unknown. Roosting
                                                                        sites may also be important for monarchs
                                                                        along their fall migration route.
----------------------------------------------------------------------------------------------------------------

Population-Level Ecology
    Monarchs, like many insects, are sensitive to environmental 
conditions (temperature and precipitation) and can experience large 
swings in population numbers from year to year in response to these 
conditions (Rend[oacute]n-Salinas et al. 2015, p. 3; Schultz et al. 
2017, pp. 345-346). During favorable conditions, monarch survival and 
reproductive rates are high and population numbers increase; 
conversely, when environmental conditions are unfavorable, survival and 
reproductive rates are low and population numbers can plummet. Thus, to 
successfully recruit over generations and years, they must be capable 
of withstanding large swings in population sizes (N). Specifically, 
they need a positive population growth rate (lambda, or [lambda]) that 
is sufficient for the species to recover from annual stochasticity.
    To support a strong growth rate, monarch populations require 
sufficiently large population sizes and an adequate quantity and 
quality of habitat to support these large population sizes. Large 
population sizes also help maintain genetic health and facilitate 
thermoregulation during the winter, which is important for good 
physical health. A sufficiently large population size may also be 
important for finding mates and repelling predators (Malcolm 2018, 
pers. comm.). Both migratory and breeding habitat need to be 
distributed throughout the landscape to ensure connectivity, allowing 
monarchs within a population to reach all portions of their range and 
to maximize lifetime fecundity (Zalucki and Lammers 2010, p. 84; Miller 
et al. 2012, p. 2).
Species-Level Ecology
    The ecological requisites at the species level include having a 
sufficient number and distribution of healthy populations to ensure the 
species can withstand annual variation in its environment (resiliency), 
catastrophes (redundancy), and novel biological and physical changes in 
its environment (representation). We describe the monarch's 
requirements for resiliency, redundancy, and representation below.
Resiliency
    Monarch populations with a robust growth rate, large effective 
population size, and suitable quality, quantity, and distribution of 
habitat conditions are better able to withstand and recover from 
environmental variability and stochastic perturbations (e.g., storms, 
dry years) than those populations that are less demographically, 
genetically, or physically healthy. Given the monarch's sensitivity to 
environmental conditions, which can cause large swings in population 
numbers year-to-year (Rend[oacute]n-Salinas et al. 2015, p. 3), 
monarchs occupying a diversity of environmental conditions and being 
widely distributed helps guard against populations being exposed to 
adverse conditions concurrently, and thus, fluctuating in synchrony. 
Asynchronous dynamics within and among populations minimizes the 
chances of concurrent losses, and thus, provides species resiliency.
Redundancy
    Monarch redundancy is best achieved by having a broad geographic 
distribution of monarchs relative to the spatial occurrence of 
catastrophic events. For the eastern North American migratory 
population, potential catastrophic events include extreme storms when 
monarchs are densely congregated and widespread drought. For the 
western North American migratory population, potential catastrophic 
events include widespread drought and co-occurrence of poor 
environmental conditions and low population abundance. For dispersed 
non-migratory populations, potentially catastrophic events include sea 
level rise, which can inundate habitat, and lethal high temperatures.
    Migratory North American monarchs are distributed across vast and 
diverse habitats across much of North America during their breeding and 
migratory seasons. However, while overwintering, most migratory 
monarchs are highly concentrated at sites in Mexico and California. 
Nonmigratory monarchs in North America are distributed in warmer, 
suitable areas throughout the year, including in parts of Florida, the 
Gulf Coast, and California. A very small proportion of the species is 
also distributed in nonnative or naturalized populations across diverse 
habitats throughout 90 countries, islands, and island groups.
Representation
    The monarch's ability to withstand novel changes in its environment 
is influenced by its adaptive capacity, which is primarily a function 
of the species' breadth of variation in biological traits and genetic 
diversity. Without such variation, species are less responsive to 
change and more prone to extinction (Spielman et al. 2004, p. 15263). 
Additionally, as populations with higher genetic diversity can more 
quickly adapt to novel changes, species with genetically healthy 
populations are better able to adapt (Ofori et al. 2017, p.

[[Page 100670]]

2). Below we describe monarch adaptive capacity by using the best 
available data.
    Migratory monarchs in North America are the ancestral population 
for all other monarch populations around the world (Pierce et al. 2014, 
p. 4; Zhan et al. 2014, p. 318; Hemstrom et al. 2022, pp. 4551-4552). 
Their unique genetics separate them from nonmigratory monarchs 
(Freedman et al. 2021, p. 7). Genetic sampling indicates that the 
monarchs from eastern and western North America have continued 
interchange between the two populations contributing to low genetic 
differentiation (Talla et al. 2020, p. 2573; Freedman et al. 2021, pp. 
7-8). During the annual breeding season, the North American migratory 
populations use a vast and diverse array of habitats. Following a long-
distance migration through more varied habitats and conditions, the 
North American migratory monarchs use sites with a diversity of 
physical structures and climatic conditions for overwintering. Having 
monarchs occupying areas of unique ecological diversity guards against 
losses of adaptive capacity due to stochastic or catastrophic events. 
Nonmigratory monarchs represent a life-history strategy that exposes 
them to selection pressures that differ from migratory monarchs.
    Eastern North American monarchs undergo long-distance migration 
every fall, a behavior that differentiates this population from 
nonmigratory populations or from migratory populations that fly shorter 
distances and to different locations. The migratory phenotype of 
monarchs in the eastern migratory population is distinct from monarchs 
in other populations that may have latent migratory phenotypes (Tenger-
Trolander et al. 2019, p. 14673). This migratory phenotype consists of 
both reproductive diapause and directional flight orientation to the 
south, and this migratory behavior of monarchs is remarkably sensitive 
to genetic and environmental change (Tenger-Trolander et al. 2019, p. 
14673). Monarchs from the eastern North American migratory population 
tend to have larger bodies and larger elongated wings compared to 
monarchs from most nonmigratory populations (Altizer and Davis 2010, 
pp. 1023-1025). Eastern North American migratory monarchs inhabit 70 
percent or more of the total area occupied by monarch butterflies in 
North America.
    Western North American monarchs also migrate long distances, 
although their migration is shorter than monarchs in eastern North 
America. Whereas eastern monarchs may fly well over 2,000 mi (3,000 km) 
to reach the Mexican overwintering sites, western monarchs reach the 
California coast by flying approximately 300 mi to 1,000 mi (500 km to 
1,600 km) (Yang et al. 2016, p. 1002; Edwards et al. 2023, p. 5). 
Western monarchs occupy warmer climates throughout the summer to 
include the farther reaches of their range while they continue to breed 
in the hotter regions (expand their range). Eastern monarchs, in 
contrast, follow more of a stepping-stone path into the northern 
States, vacating areas as they warm and recolonizing their range.
    Western North American migratory monarchs occupy as much as 30 
percent of the total area occupied by monarch butterflies in North 
America (Dilts et al. 2019, p. 11). Western monarchs use ecologically 
different breeding, migrating, and overwintering habitats (Brower et 
al. 1995, p. 542) compared to monarchs in eastern North America. 
Differences in breeding habitat include climate (Zalucki and Rochester 
2004, pp. 220-221) and availability and abundance of native nectar and 
native milkweed plants (Borders and Lee-M[auml]der 2015, entire). The 
West is generally hotter and drier than the East, and the milkweed and 
nectar resources used by monarchs in the West and East differ (Dilts et 
al. 2019, entire). In the fall, western monarchs migrate from Canada 
and States west of the Rockies to overwintering groves located 
primarily along the California coast south into Baja California, Mexico 
(Jepsen and Black 2015, pp. 147-156). Roosting tree species used by 
western monarchs for overwintering are different than those used by the 
eastern population and include blue gum eucalyptus, Monterey pine, and 
Monterey cypress (Griffiths and Villablanca 2015, pp. 43-44). The 
western population has fewer monarchs, spread out among hundreds of 
overwintering sites compared to fewer than 20 sites in Mexico for the 
eastern population (Jepsen and Black 2015, pp. 147-156; Vidal and 
Rend[oacute]n-Salinas 2014, entire).
    Migratory monarchs in eastern and western North America may also 
contribute unique phenotypic variation in wing morphology/coloration, 
lipid reserves, and reproductive behavior (Talla et al. 2020, pp. 2572-
2573; Freedman and Dingle 2018, p. 66; Davis 2009, p. 3; Brower et al. 
1995, p. 542; Herman et al. 1989, pp. 52-54; 56-57). Compared to 
monarchs in western North America and to nonmigratory monarchs in 
southern Florida, eastern North American monarchs have lower rates of 
infection by the protozoan parasite OE (<10 percent; Altizer et al. 
2000, p. 131), which may be due in part to their long-distance 
migration (Bartel et al. 2011, p. 348). Migratory monarchs in the West 
have OE infection rates (averaging 5-30 percent) that are lower than 
most nonmigratory populations but higher than the rates of infection in 
migratory monarchs in eastern North America (Altizer and de Roode 2015, 
p. 91).
    Resident (nonmigratory) monarchs in North America now live in areas 
where milkweed availability and climate permit year-round breeding, and 
thus are able to reside continually without migrating. These 
nonmigratory monarchs in southern Florida are genetically distinct from 
the migratory North American monarchs, although the southern Florida 
population gets an annual influx of individuals from the eastern 
migratory monarch population (Knight and Brower 2009, p. 821; Zhan et 
al. 2014, p. 322). Also, some monarchs remain or become reproductively 
active and breed throughout the winter along the Gulf Coast, the 
southern Atlantic Coast, and the southern Pacific Coast (Howard et al. 
2010, p. 3; Satterfield et al. 2016, p. 346). These monarchs are more 
likely to be infected with OE (Satterfield et al. 2016, p. 347; 2018, 
p. 1676), and there is some question of whether some of the offspring 
of these individuals might emerge in diapause and continue to Mexico or 
California overwintering sites later in the season (Batalden and 
Oberhauser 2015, p. 223). The best available information, including the 
quantity and quality of the habitat, indicates that the total number of 
resident monarchs appears to be quite small relative to the North 
American migratory populations that overwinter in Mexico and 
California. Some experts consider the resident monarch populations 
demographic sinks (see Crone and Schultz 2021, p. 1536), requiring 
continual influxes of monarchs from migratory populations to sustain 
them.
    Nonmigratory Florida monarchs experience some of the highest 
recorded OE infection rates compared to other monarchs worldwide and 
particularly high rates compared to migratory eastern and western North 
America monarch infection rates (75-100 percent average infection rates 
in Florida vs. 5-30 percent infection rates in the western North 
American population and less than 10 percent infection rates in the 
eastern North American population; Altizer and de Roode 2015, p. 91). 
This may be due both to their inability to escape infected habitat, as 
well as the nonmigratory behavior not leading to any migratory culling 
(the removal of

[[Page 100671]]

less fit individuals from a population due to their inability to 
migrate) (Bartel et al. 2011, entire). While we assume most monarchs 
found in southern Florida are nonmigratory, it is possible that some 
are migratory (Dockx et al. 2023, pp. 314-317).
    In the West, the population of migratory monarchs has declined from 
several million butterflies in the 1980s (Schultz et al. 2017, p. 345) 
to current levels (figure 1b). Concurrently in the West, a portion of 
nonmigratory monarch butterflies in urban gardens has been growing 
(Crone and Schultz 2021, entire). The increase in numbers of these 
nonmigratory monarchs do not seem to make up for the decline of the 
migratory population (Crone and Schultz 2021, entire). Additionally, 
the nonmigratory portion also probably lacks the demographic capacity 
to expand its range inland during summer months. Nonmigratory monarch 
butterflies build up high levels of OE, at least in part because of a 
lack of migratory culling and migratory escape (Satterfield et al. 
2015, pp. 4-5). In California, about 8 percent of migratory monarch 
butterflies are infected with OE, compared to about 75 percent of 
nonmigratory individuals (Satterfield et al. 2016, p. 346). OE-infected 
monarch butterflies have both lower survival and lower egg-laying rates 
and produce only about 0.8 adult daughters per female on average (Crone 
and Schultz 2021, Supplement S4). While this rate of increase is enough 
for nonmigratory monarch butterflies to persist in urban areas, it does 
not allow them to expand to other western States (Crone and Schultz 
2021, p. 1536). Additional information on the genetic structuring of 
monarchs outside of continental North America is available in the SSA 
report (Service 2024a, appendix 2).
    In order to better understand the population dynamics and 
contributions from the nonmigratory populations, we are requesting 
additional information on resident monarchs in southern Florida, the 
Gulf Coast, the southern Atlantic Coast, and the southern Pacific 
Coast. To submit information, see the Information Requested section.
Threats
    We have little to no information on positive or negative influences 
acting upon monarchs occurring outside of the eastern and western North 
American populations. There is limited information on predation, 
parasitism, and disease outside of eastern and western North American 
populations. Given this limited information, we were unable to 
ascertain to what extent predation, parasitism, and disease impact the 
monarch populations outside of the eastern and western North American 
populations. Similarly, while data suggest global use of insecticides 
is increasing, we are unable to estimate the degree of overlap with 
monarch populations and thus derive a credible projection of impact on 
the monarch populations outside of the eastern and western North 
American populations.
    The primary drivers affecting the health of the two North American 
migratory populations are loss and degradation of breeding, migratory, 
and overwintering habitat (from past conversion of grasslands and 
shrublands to agriculture and widespread use of herbicides; logging/
thinning at overwintering sites in Mexico; urban development, 
senescence, and incompatible management of overwintering sites in 
California; and drought); exposure to insecticides; and effects of 
climate change. Many other influences to monarchs were evaluated, 
including disease, parasitism, captive rearing, collection, impacts of 
tourism at overwintering sites, invasive swallow-wort plants, vehicle 
mortality, and natural catastrophes. However, these other potential 
influences were not determined to be key population drivers (Service 
2024a, pp. 109-111).
    Because the conversion of grasslands to agriculture was a key 
driver for past population declines, current and future activities that 
may remove milkweed and nectar resources within the breeding and 
migratory range, but that do not result in conversion of native or 
naturalized grassland, shrubland, or forested habitats and do not 
result in significant population-level mortality, are, therefore, not 
considered key population drivers. These include habitat restoration 
and management activities, livestock grazing and routine ranching 
activities, routine agricultural activities and conservation practices, 
fire management, silviculture and forest management, management of 
habitat on residential and other developed properties, and vegetation 
management activities when monarchs are not present. Given that so much 
milkweed has been lost historically and that monarchs are impacted by 
the ongoing effects of this past habitat loss and degradation, we need 
an approach that encourages landowners to add and maintain habitat in 
order to achieve a significant increase in the availability of milkweed 
and nectar resources. We expect localized removal of milkweed and 
nectar plants will be outweighed by an overall addition of these 
resources across the landscape, making broadscale public support for 
monarch conservation vitally important. For example, landscape-scale 
habitat restoration and management activities that provide for the 
habitat needs of monarch butterflies (e.g., mowing, haying native 
rangeland, prescribed and cultural burning, and control of invasive 
plants or noxious weeds) may remove milkweed and could result in loss 
of monarchs in the short term but would also increase the overall 
quality and quantity of breeding habitat, which is likely to benefit 
monarch populations in the long term. We are requesting information on 
both our identified key threats as well as other potential threats to 
the species, such as collisions with wind turbines (see Information 
Requested). The key influences for monarch butterflies are discussed 
below.

Availability, Distribution, and Quality of Breeding Habitat and 
Migratory Habitat

    The availability of milkweed is essential to monarch reproduction 
and survival. Reductions in milkweed are cited as a key driver in 
monarch declines (Brower et al. 2012, p. 97; Pleasants and Oberhauser 
2013, p. 141; Inamine et al. 2016, p. 1081; Thogmartin et al. 2017a, p. 
12; Waterbury and Potter 2018, pp. 42-44; Saunders et al. 2019, p. 
8612).
    A majority of the past milkweed loss has occurred in agricultural 
lands, where intensive herbicide usage for weed control has resulted in 
widespread milkweed eradication. More than 860 million milkweed stems 
were lost in the Midwest between 1999 and 2014, a decline of almost 40 
percent (Pleasants 2017, p. 48). Approximately 89 and 94 percent of 
corn and soybean crop acreages, respectively, are planted as glyphosate 
(herbicide)-tolerant crops (USDA 2018, unpaginated). When glyphosate is 
sprayed in or near fields where crops are produced, it kills the 
milkweed without harming the glyphosate-tolerant crops. Glyphosate use 
in western agricultural lands has also increased dramatically since the 
1990s, especially within the Central Valley of California, Snake River 
Plain of Idaho, and the Columbia River Basin, which spans the border 
between Washington and Oregon (USGS NAWQA 2017, unpaginated; Waterbury 
and Potter 2018, p. 42). As weed species develop increasing resistance 
to glyphosate, other herbicide (e.g., dicamba)-tolerant crops are 
developed, which can lead to a corresponding increase in use of those 
herbicides. Accordingly, herbicide impacts to milkweed and nectar 
plants will continue to impact monarch resources in agricultural lands.

[[Page 100672]]

    Milkweed has also been lost on the landscape through development 
and conversion of grasslands (Lark et al. 2015, pp. 3-4). Between 2008 
and 2016, a total of 4.9 million acres of grassland were converted to 
new cropland, including up to 3 million acres of Conservation Reserve 
Program land (Lark et al. 2015, p. 5). Past loss of agricultural 
milkweeds in the Midwest has resulted in an estimated 81 percent 
decline in monarch production, in part because monarch egg densities 
were higher on milkweed in agricultural fields (3.89 times more eggs 
than on non-agricultural milkweed; Pleasants and Oberhauser 2013, pp. 
139-140). This situation particularly impacts the eastern monarch 
population because more Mexico overwintering monarchs originate from 
the Midwest crop belt region than any other region (with estimates 
ranging from 38 percent to over 85 percent of all overwintering 
monarchs originating from the Midwest; Wassenaar and Hobson 1998, pp. 
15438-15439; Flockhart et al. 2017, p. 2568). Development and 
conversion of grasslands will continue to impact monarch resources in 
agricultural lands.
    Losses of nectar sources have also been implicated as a potential 
key driver in monarch declines (Inamine et al. 2016, p. 1081; 
Thogmartin et al. 2017a, p. 12; Saunders et al. 2019, p. 8612). Losses 
of nectar resources are due to the same stressors identified above for 
milkweed resources. Additionally, with a warming climate, drought 
impacts may affect the availability of nectar sources, especially in 
the western population and in the migratory bottleneck through Mexico 
and into Texas for the eastern population (see Climate Change Effects, 
below).
    Our future analyses forecast a range of projections for future 
nectar and milkweed throughout the monarch butterfly's range. While 
these breeding and migratory habitat resources show signs of regional 
stabilization or increase, even the best case scenario increases are 
less than the amount of milkweed and nectar resources that have been 
lost. The reduced amount of breeding and migratory habitat continues to 
negatively impact the viability of the migratory North American 
monarchs. Monarch conservation needs an approach that encourages and 
incentivizes landowners to add milkweeds and nectar resources and 
implement actions to maintain this habitat. Unlike with some at-risk 
species, the monarch's general habitat usage and wide distribution 
allow a broad range of landowners to participate in actions to support 
the species. Conservation for the species can occur on land parcels 
ranging from quite small to very large, including gardens, parks, 
grasslands, agricultural areas, and more.

Availability, Distribution, and Quality of Overwintering Habitat

    Both western and eastern monarchs rely on the microclimate provided 
by the trees at their overwintering sites (Leong et al. 2004, entire; 
Williams and Brower 2015, entire). Loss of trees occurs at 
overwintering sites in Mexico primarily through small- and large-scale 
logging, storms, and an increasingly unsuitable climate (see Climate 
Change Effects below). Most overwintering sites used by eastern 
monarchs occur within the Monarch Butterfly Biosphere Reserve 
(Reserve), a 139,019-ac (56,259-ha) protected area in Central Mexico. 
Within this area, logging is banned within the 33,485-ac (13,551-ha) 
core zone (Ram[iacute]rez et al. 2015, p. 158). However, logging has 
continued to occur both legally (including salvage logging allowed 
after storms) and illegally at multiple colonies within the Reserve 
(Vidal et al. 2014, pp. 180-185; Brower et al. 2016, entire).
    Logging was estimated in the core zone of the Reserve from 2002 
through 2012 (Vidal et al. 2014, p. 180). Within this period, 5,384 
acres (2,179 ha) of core zone were either deforested (less than 10 
percent canopy cover remained; 3,099 ac (1,254 ha)) or degraded (a 
decrease in canopy cover; 2,286 ac (925 ha)). Most of these losses were 
attributed to illegal logging (5,083 ac (2,057 ha)), with the remaining 
301 acres (122 ha) lost due to floods, drought, strong winds, and fire. 
Current estimates of forest loss throughout the Reserve vary from 0-2.4 
percent per year (Ram[iacute]rez et al. 2015, p. 163). While anti-
logging and reforestation efforts are underway (L[oacute]pez-
Garc[iacute]a 2022, p. 245), logging is still ongoing within the 
Reserve (Brower et al. 2016, entire). Although clearcutting of forests 
destroys habitat directly, thinning of the forest also changes the 
microclimate needed by overwintering monarchs, making them more 
susceptible to winter mortality (Brower et al. 2011, p. 43).
    Western monarch overwintering habitat along the Pacific Coast has 
been subject to loss through various forms of development, particularly 
urban development (Sakai and Calvert 1991, p. 149; Frey and Schaffner 
2004, p. 172). Since the 1980s, development has caused the loss of at 
least 63 known California overwintering sites (Sakai and Calvert 1991, 
pp. 148-49, Meade 1999, p. 97-100, Xerces Society 2024a, unpaginated). 
Habitat alteration, such as through natural tree senescence and 
improper grove management, can also alter the microclimate of the 
western overwintering sites, leading to less suitable habitat 
conditions (Jepsen et al. 2015, p. 17). Many other stressors can work 
alone or in tandem on the western overwintering sites, including 
disease and pests that impact the trees used for overwintering. Fire is 
also a threat, both indirectly through habitat loss and directly to 
overwintering monarchs (Pelton et al. 2016, pp. 28, 32). Drought in the 
West can further exacerbate the stressors on the western overwintering 
sites (see Climate Change Effects below).

Insecticide Exposure

    Insecticides are pesticides with chemical properties that are 
designed to kill insects and most are non-specific and broad-spectrum 
in nature. That is, insects exposed to these insecticides are 
susceptible to mortality or sublethal effects. Furthermore, the larvae 
of many lepidopterans (i.e., insects in the order that includes 
butterflies and moths) are considered major pest species, and 
insecticides are tested specifically on this taxon to ensure that they 
will effectively kill individuals at application rates indicated on 
product labels. Even though monarchs are not the target species of 
these products, they may be exposed to insecticides where they are 
applied and in areas beyond the insecticide application sites due to 
drift (Olaya-Arenas and Kaplan 2019, p. 1; Halsch et al. 2020, p. 3).
    Insecticide impacts to monarchs are primarily influenced by the 
extent to which monarchs are exposed to insecticides throughout their 
range. Although insecticide use is most often associated with 
agricultural production (e.g., between 2005 and 2012, 60 percent of 
insecticides applied occurred on agricultural lands; EPA 2017, p. 11), 
any habitat where monarchs are found may be subject to insecticide use. 
Insecticides can be used for insect pest control anywhere there is a 
pest outbreak or for general pest prevention. Homeowners may treat 
yards and gardens to protect plants from pests or purchase plants from 
nurseries that sell plants pre-treated or grown from seeds treated with 
insecticides as ornamentals. Natural areas, such as forests and parks, 
may be treated to control for insects that defoliate, bore into wood, 
or otherwise damage trees. Outbreaks of pests, such as spongy moths, 
mosquitoes, Mormon crickets, or grasshoppers, may trigger insecticide 
treatments over large areas to control populations. Use of insecticides 
in vector control, especially pyrethroids and organophosphates, may be 
significant in areas of the country where mosquitoes pose a public 
health threat

[[Page 100673]]

or reach nuisance levels. The most widely used classes of insecticides 
include organophosphates, pyrethroids, and neonicotinoids. Studies 
looking specifically at dose-response of monarchs to neonicotinoids, 
organophosphates, and pyrethroids have demonstrated monarch toxicity at 
product label application rates and field concentration levels (e.g., 
Krischik et al. 2015, entire; James 2019, entire; Krishnan et al. 2020, 
entire; Bargar et al. 2020, entire).
    Insecticides are a threat to monarchs based on their mode of action 
to target insects and their potential exposure to monarchs. Monarchs 
can be exposed to liquid insecticides from direct spray at the time of 
application, contact with vegetation contaminated with an insecticide, 
or ingestion of leaves or nectar contaminated with insecticide 
following a spray. This exposure can occur on the site of application 
or in adjacent areas as a result of insecticide drift. Biopesticides, 
another type of insecticide, generally affect only the target pest and 
closely related organisms. These products contrast with broad-spectrum 
and conventional insecticides that target all insects. The primary 
identified biopesticide exposure threat to monarchs is limited to the 
liquid application of certain types of Bacillus thuringiensis (Bt) that 
are active against lepidopterans and often used to control caterpillar 
pests (such as spongy moth).
    Monarchs may also be exposed to insecticides in forms other than 
liquids, such as those that have been systemically incorporated into 
plant tissues on which monarchs feed (e.g., milkweed leaves, flowers, 
pollen, and nectar) or dust that has drifted off treated seeds at the 
time of planting. Numerous types of insecticides may be incorporated 
into plants systemically or used to treat seeds, including 
neonicotinoids. However, there are limited data to suggest that 
insecticides used in this manner achieve concentrations likely to 
result in negative effects to monarchs. Thus, while monarchs may be 
exposed to insecticide residues from these application methods, the 
available information indicates that negative effects from insecticide 
residues are likely minimal. For insecticides applied in solid forms 
such as granules, no exposure is expected to monarchs; thus, negative 
effects from application of pesticides in solid forms are unlikely.
    Herbicides and fungicides are used within or near areas where 
monarchs may be present; however, only a subset of these have data 
showing direct negative effects to insects (i.e., as opposed to 
insecticides, where all pesticides within this class will cause 
negative effects to insects). As such, the information indicates the 
negative effects to monarchs from exposure to herbicides and fungicides 
is likely minor compared to the direct effects of exposure to 
insecticides.
    See Appendix 5--Supplementary Information About Pesticides in the 
monarch butterfly SSA report (Service 2024a, pp. 123-146) for further 
discussion of the risk of pesticides to the monarch, including data, 
references, and supporting information.

Climate Change Effects

    Climate change can affect monarchs both directly and indirectly 
(Nail and Oberhauser 2015, entire) on overwintering, migratory, and 
breeding grounds. Increasing storm frequency in the Mexican 
overwintering colonies can lead to catastrophic (up to 80 percent) 
mortality through the freezing temperatures that accompany these storms 
(Anderson and Brower 1996, p. 112; Brower et al. 2004, entire). 
Precipitation is predicted to increase during the winter when monarchs 
are present in Mexico (Oberhauser and Peterson 2003, p. 14067). Severe 
drought can cause tree loss and degradation, decreasing the 
availability and quality of overwintering roosting habitat in 
California as well (Pelton et al. 2016, p. 29). Eucalyptus trees, the 
dominant tree species in many of the groves, are drought sensitive and 
become vulnerable to infestation by insect borers when they are 
stressed, which can exacerbate tree loss in these groves (Marcar et al. 
1995, p. 46; Paine and Millar 2002, p. 148). Eucalyptus loss and 
degradation reduces availability of roosting habitat, lessens wind 
protection, and eliminates the primary overwintering source of nectar 
at many sites. Other dominant trees, such as Monterey pines and 
Monterey cypress, are more resistant to drought, but are the primary 
species in fewer than 25 percent of overwintering sites. Although 
overwintering grounds are widespread, drought could be equally as 
widespread, such that it could occur throughout many or most of the 
overwintering sites simultaneously. Given the above, extreme drought at 
overwintering sites poses a catastrophic risk for the western monarch 
population.
    Monarchs need a very specific microclimate at their overwintering 
sites not just to avoid storm mortality, but also to avoid early fat 
depletion. Changing precipitation patterns and temperatures may 
influence the microclimate needed by overwintering monarchs (Williams 
and Brower 2015, p. 116). For example, current modeling of the 
monarch's fundamental niche predicts the loss of 38.6 to 69.8 percent 
of current suitable habitat within the Reserve due primarily to 
expected temperature changes (Zagorski 2016, p. 17). In western North 
America, climate change is predicted to cause a significant change in 
the distribution of overwintering monarchs in coastal California 
(Fisher et al. 2018, p. 10). While modeling projections suggest an 
inland and upslope displacement of suitable overwintering conditions by 
the year 2050, the best available evidence does not indicate that 
monarchs would move to or use these upslope areas (Fisher et al. 2018, 
pp. 10, 13-14).
    In addition to the direct impact of climate change on overwintering 
monarchs, the Mexico overwintering sites are predicted to be less 
suitable for oyamel fir trees, the predominant monarch roosting tree. 
The overwintering sites are predicted to become increasingly warm 
throughout the year, potentially making 50 percent or more of the sites 
unsuitable for oyamel fir trees in 2030 (S[aacute]enz-Romero et al. 
2012, p. 102; Ram[iacute]rez et al. 2015, p. 167). Widespread drought 
is similarly likely to negatively impact trees in the western 
overwintering areas both directly and indirectly due to increased 
susceptibility to pests (Paine and Millar 2002, p. 148).
    Direct effects of climate change, particularly increasing 
temperatures, may impact monarch fecundity (reproductive rate) 
(Oberhauser 1997, pp. 168-169), mating success (Solensky and Oberhauser 
2009, p. 333), and survival during migration and while overwintering 
(Masters et al. 1988, entire; Alonso-Mej[iacute]a et al. 1997, entire). 
Laboratory studies indicate optimal temperatures for monarch range 
between 81-84 [deg]F (27-29 [deg]C) with sublethal effects beginning 
around 86-97 [deg]F (30-36 [deg]C) range and an upper lethal thermal 
limit of 108 [deg]F (42 [deg]C) (Zalucki 1982, p. 243; York and 
Oberhauser 2002, p. 294; Zalucki and Rochester 2004, p. 225; Nail et 
al. 2015, p. 101). Research also indicates that cooler nighttime 
temperatures provide respite from elevated daytime temperatures and are 
important in allowing monarchs to survive temperature stress (Nail et 
al. 2015, p. 104). Temperatures consistently above 91-95 [deg]F (33-35 
[deg]C) are unsuitable for monarchs and may account for their general 
absence from the southern U.S. after spring (Malcolm et al. 1987, p. 
78; Zalucki and Rochester 1999, pp. 155-157).

[[Page 100674]]

    High temperatures and drought conditions may be particularly 
impactful during the crucial spring migration (Taylor 2020, pers. 
comm.). Spring temperatures and precipitation in the southern U.S. 
portion of the migratory range have been modeled to have a high 
relative importance affecting summer population size of eastern 
monarchs (a larger impact than compared to summer weather, summer 
herbicide use in cropland, and late-winter population size) (Zylstra et 
al. 2021, p. 1443). However, considerable uncertainty remains regarding 
the extent, intensity, and biological impacts of climate change during 
spring migration (Neupane et al. 2022, pp. 10-14). While increased 
temperatures may reduce monarch habitat in some areas, the climatically 
suitable niche for monarchs may increase northward, potentially 
increasing their summer breeding grounds if both monarchs and milkweed 
are able to adapt and track this niche northward (Lemoine 2015, pp. 10-
17).
    A warming climate may influence breeding habitat by altering 
suitable locations for both monarchs (Batalden et al. 2007, pp. 1369-
1370) and their milkweed host plant (Lemoine 2015, entire). Nectar 
resources during migration may be reduced under climate conditions 
(decreased precipitation) projected for south-central Texas (Saunders 
et al. 2019, p. 8612). Drought may also influence the amount and 
availability of nectar needed for migrating butterflies (Brower et al. 
2015, entire; Stevens and Frey 2010, p. 740; Espeset et al. 2016, p. 
826). Widespread drought caused by climate change is expected to 
increase into the future (IPCC 2023, p. 69) negatively impacting 
monarchs and their habitat.
    Sea level rise is increasing due to climate change. These rising 
sea levels are likely to impact monarch populations in coastal areas 
(e.g., along the Gulf Coast) and low lying islands through loss of 
habitat (TBCSAP 2015, entire; IPCC 2023, p. 69).
    Climate change may additionally impact monarchs in ways that are 
more difficult to measure. This may include phenological mismatch 
(e.g., timing of milkweed and nectar sources not aligning with monarch 
migration; Thogmartin et al. 2017a, p. 13) or range mismatch with 
associated species. For example, a change in environmental suitability 
could cause a range shift for monarch predators and parasitoids, 
increasing or decreasing their overlap with the monarch's range 
(McCoshum et al. 2016, p. 229-233).

Conservation Efforts and Regulatory Mechanisms

    While many factors have been implicated in the decline in monarch 
populations, the loss of milkweed and nectar resources (i.e., breeding 
and migratory habitat) has been targeted as the threat that can be most 
easily addressed through conservation efforts. Because of the monarch 
butterfly's general habitat use and wide distribution, all sectors of 
society, including the general public, have an opportunity to 
participate in a broad range of conservation efforts throughout the 
species' range. Protection, restoration, enhancement, and creation of 
habitat is a central aspect of recent monarch conservation strategies, 
thus highlighting the importance of restoring and enhancing milkweed 
and nectar resources (Oberhauser et al. 2017, pp. 56-58; Pleasants 
2017, p. 43; Thogmartin et al. 2017a, pp. 2-3; MAFWA 2018, p. 52; 
Pelton et al. 2019, pp. 4-5, WAFWA 2019, p. 41). Management at 
overwintering sites in California has also been targeted to improve the 
status of western North American monarch butterflies (Pelton et al. 
2019, p. 4; WAFWA 2019, pp. 37-40). We are not aware of conservation 
actions for the populations outside of eastern and western North 
America, but conservation measures for the eastern and western North 
American populations are described below.
    Major overarching landscape-level conservation plans and efforts 
include the Mid-America Monarch Conservation Strategy developed by the 
Midwest Association of Fish and Wildlife Agencies (MAFWA) and the 
Western Monarch Butterfly Conservation Plan developed by the Western 
Association of Fish and Wildlife Agencies (WAFWA). The Mid-America 
Monarch Conservation Strategy established a goal of adding 1.3 billion 
stems of milkweed on the landscape by 2038 (MAFWA 2018, p. 42). The 
1.3-billion-stem goal is an estimated target for adding enough breeding 
and migratory habitat to support 14.8 ac (6 ha) of forest occupied by 
overwintering monarchs for the eastern North American population 
(Thogmartin et al. 2017b, pp. 2-3). Twenty-nine States--including 
Arkansas, Connecticut, Delaware, Illinois, Indiana, Iowa, Kansas, 
Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, 
Missouri, Nebraska, New Hampshire, New Jersey, New York, North Dakota, 
Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Texas, 
Vermont, Virginia, West Virginia, and Wisconsin--have agreed to 
participate in the effort to reach the 1.3-billion-stem goal, which 
will also need contributions from multiple sectors of society, 
including private landowners, agricultural and nongovernmental 
organizations, rights-of-way organizations, and Federal, State, and 
local governments.
    The Western Monarch Butterfly Conservation Plan currently 
encompasses the States of Arizona, California, Idaho, Nevada, Oregon, 
Utah, and Washington, which comprise the core of the western monarch 
range (WAFWA 2019, p. 3). The plan includes short-term goals of: (1) 
protecting and managing 50 percent of all currently known and active 
monarch overwintering sites, including 90 percent of the most important 
overwintering sites by 2029; and (2) providing a minimum of 50,000 
additional acres of monarch-friendly habitat in California's Central 
Valley and adjacent foothills by 2029. It also includes overwintering 
and breeding habitat conservation strategies, education and outreach 
strategies, and research and monitoring needs. Many land managers who 
oversee overwintering sites in California have developed and 
implemented grove management strategies or have included monarch groves 
in their general management plans. Conservation efforts in California's 
Central Valley currently amount to nearly 9,000 ac (3,600 ha). As of 
September 2024, State agencies had implemented milkweed restoration 
efforts on over 8,780,404 ac (3,553,303 ha), adding more than an 
estimated 546 million milkweed stems to the landscape nationwide.
    In early 2020, the Nationwide Candidate Conservation Agreement for 
Monarch Butterfly on Energy and Transportation Lands: An Integrated 
Candidate Conservation Agreement with Assurances (CCAA) and Candidate 
Conservation Agreement (CCA) was finalized and is contributing to MAFWA 
Strategy and WAFWA Plan goals. Under this agreement, energy and 
transportation entities are providing habitat for the species along 
energy and transportation rights-of-way corridors across the country. 
Participants carry out conservation measures to reduce or remove 
threats to the species and create and maintain habitat annually. In 
exchange for implementing voluntary conservation efforts and meeting 
specific requirements and criteria, those businesses and organizations 
enrolled in this CCAA/CCA receive assurance from the Service that they 
will not have to implement additional conservation measures should the 
species be listed. The goal of this CCAA/CCA is

[[Page 100675]]

enrollment of up to 26 million acres of land in the agreement, 
providing more than 300 million additional stems of milkweed (Rights-
of-Way as Habitat Working Group 2020, p. 3). As of June 2024, this 
CCAA/CCA had 57 enrollees with over 981,812 ac (397,325 ha) of enrolled 
habitat.
    Many conservation efforts implemented under Federal, Tribal, State, 
or other programs, such as the Farm Service Agency's Conservation 
Reserve Program; the Natural Resource Conservation Service's 
Environmental Quality Incentives Program, Agricultural Conservation 
Easement Program and Conservation Stewardship Program; and the 
Service's Partners for Fish and Wildlife Program, are expected to 
contribute to the overarching habitat and population goals of the MAFWA 
Strategy and WAFWA Plan. Smaller conservation efforts, such as 
pollinator gardens, implemented by local governments, nongovernmental 
organizations, private businesses, and interested individuals will also 
play an important role in reaching habitat and population goals 
established in the MAFWA Strategy and WAFWA Plan.
    Many land managers who oversee overwintering sites in California 
have developed and implemented grove management strategies or have 
included monarch groves in their general management plans. Many others 
are in the process of developing grove management plans. As of January 
2024, grove management plans are being implemented at no fewer than 24 
overwintering sites and are currently being developed for at least a 
dozen more. Management and restoration of these sites may include 
activities such as replacing dead trees, modifying canopy structure, 
planting fall- and winter-blooming shrubs as nectar sources, and 
addressing monarch predation issues (Jepsen et al. 2017, entire).
    The Service developed the Monarch Conservation Database (MCD) to 
capture information about monarch conservation plans and efforts to 
inform the listing decision. As of September 2024, the MCD had 145,455 
complete monarch conservation effort records that have a status of 
completed, implemented, or planned since 2014 and 126 monarch 
conservation plans. These efforts constitute a total of 10,457,316 ac 
(4,231,926 ha) of land area in the United States (10,246,876 ac 
(4,146,764 ha) and 178,920 ac (72,406 ha) in the eastern and western 
populations, respectively) enhanced or created for monarchs, with the 
most common conservation effort being direct planting of milkweed and 
other nectar resources (note that these values include all completed, 
implemented, and not yet completed efforts; completed and implemented 
efforts to date total 7,415,731 ac (3,001,040 ha) nationally). These 
conservation efforts are increasing the amount of milkweed and nectar 
resources on the landscape. However, additional milkweed and nectar 
resources are required, as initial estimates of the amount of acreage 
needed to reach the 1.3-billion-stem goal within the MAFWA Strategy 
planning area were around 20 million acres.
    In addition to conservation measures for monarch butterflies, there 
are also mechanisms that regulate direct and indirect threats to the 
species. One such mechanism is the Federal Insecticide, Fungicide, and 
Rodenticide Act (FIFRA), which provides for Federal regulation of 
pesticide distribution, sale, and use. The term pesticide includes 
insecticides, which can directly kill monarchs upon exposure, and 
herbicides that can indirectly affect monarchs by impacting their 
milkweed and nectar resources. All pesticides distributed or sold in 
the United States must be registered (licensed) by the U.S. 
Environmental Protection Agency (EPA). Before the EPA registers a 
pesticide under FIFRA, the applicant must show, among other things, 
that using the pesticide according to specifications ``will not 
generally cause unreasonable adverse effects on the environment.''
    In 2021, the EPA began developing a comprehensive, long-term 
approach to meeting its section 7(a)(2) obligations for FIFRA actions 
(EPA 2022, unpaginated). As part of that work, the EPA in August 2024 
finalized its first-ever strategy to identify which agricultural uses 
of conventional herbicides impact listed species and how to determine 
the amount and location of mitigation measures for those herbicides, 
hereon referred to as the Herbicide Strategy (EPA 2024a, entire). The 
strategy covers listed plants and listed animals whose survival depends 
on listed plants, including many insects that depend on plants for 
food. The EPA has begun applying the strategy to the registration of 
new pesticide registrations (EPA 2024d, unpaginated) and expects to 
apply the strategy when the agency reevaluates the registration of 
existing pesticides every 15 years.
    Similarly, in July 2024 the EPA released its draft Insecticide 
Strategy, which proposes a framework to identify which agricultural 
uses of conventional insecticides impact listed species and how to 
determine the amount and location of mitigation measures for those 
insecticides (EPA 2024b, entire). The EPA has agreed to finalize the 
Insecticide Strategy by March 31, 2025, and then expects to apply it 
when the agency registers a new insecticide or reevaluates an existing 
one. The EPA is also pursuing other initiatives to minimize pesticide 
impacts on listed species, including through section 7(a)(2) 
consultations with FWS on individual pesticide active ingredients and 
through its Vulnerable Species Action Plan, which identifies mitigation 
measures for listed species particularly vulnerable to pesticides (EPA 
2024c, entire).
    Under the authority of the Plant Protection Act, the U.S. 
Department of Agriculture (USDA) regulates the importation and movement 
of plant pests, which covers plant-feeding insects such as the monarch 
butterfly. Under this regulation, a permit from USDA-Animal and Plant 
Health Inspection Service (APHIS) is required for the importation, 
interstate movement, and environmental release of butterflies, 
including monarchs. However, multiple States, including Alaska, 
Arizona, Connecticut, Hawaii, Montana, and Nevada, plus Puerto Rico, 
the Virgin Islands, and Guam, prohibit importation and/or interstate 
movement of monarchs for the purpose of environmental release. In 
addition, APHIS does not allow the movement of monarchs across the 
Continental Divide for environmental release.
    Despite these conservation efforts and regulatory mechanisms, the 
continued threats facing the monarch butterfly have not been 
ameliorated.

Cumulative Effects

    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have 
analyzed the cumulative effects of identified threats and conservation 
actions on the species. The best available scientific information 
indicates that there are synergistic and cumulative interactions among 
the factors influencing monarch butterfly viability. For example, 
climate change can impact the monarch directly through increased 
temperatures and can also impact other potential threats to the 
species, including habitat availability, disease, and predators. We 
incorporate the cumulative effects into our SSA analysis when we 
characterize the current and future condition of the species. To assess 
the current and future condition of the species, we evaluate the 
effects of all the relevant factors that may be influencing the 
species, including threats and conservation

[[Page 100676]]

efforts. Because the SSA framework considers not just the presence of 
the factors, but to what degree they collectively influence risk to the 
entire species, our assessment integrates the cumulative effects of the 
factors and replaces a standalone cumulative-effects analysis.

Current Condition

Eastern North American Population
    Based on the past annual censuses, the eastern North American 
population has been generally declining over the last 30 years (figure 
1a). Because it is not possible to count individual monarchs at the 
overwintering sites in Mexico, the size of the eastern North American 
population is measured based on the area occupied by clustered 
monarchs. Although the numbers at the overwintering sites have 
declined, we did not find a corresponding change in the spatial extent 
of the population during the breeding season. We developed a population 
model that incorporated the current size, growth rate, and year-to-year 
variability of the eastern North American population. The results 
indicate that the probability of the population abundance reaching the 
point at which extinction is inevitable (``probability of extinction'') 
in is less than 10 percent within 10 years (Service 2024a, p. 29). The 
probability of extinction does not account for risks from catastrophic 
events (discussed below in Future Condition).
Western North American Population
    Based on the past annual censuses, the western North American 
population has been generally declining over the last 27 years, despite 
an increasing number of sites being surveyed (figure 1b). We developed 
a similar model for the western North American population as we did for 
the eastern population. Under current conditions, the risk of 
extinction is predicted to increase sharply over time, between 60 to 68 
percent within 10 years (Service 2024a, p. 30). The probability of 
extinction does not account for risks from catastrophic events 
(discussed below in Future Condition).
[GRAPHIC] [TIFF OMITTED] TP12DE24.000


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[GRAPHIC] [TIFF OMITTED] TP12DE24.001

Figure 1--(a.) Area occupied (in hectares) by eastern North American 
monarch butterflies at overwintering sites in Mexico. Year displayed is 
the beginning year for the winter (e.g., 2017 represents the number for 
the winter of 2017-2018). (Data from Rend[oacute]n-Salinas et al. 2024 
(p. 3).)
(b.) Survey counts showing the number of western North American monarch 
butterflies observed at overwintering sites (bars). The black line 
shows the number of sites monitored (survey effort) for a given year. 
(Data from the Xerces Society for Invertebrate Conservation (2024a, 
entire).)
Dispersed Nonmigratory Populations
    Limited information is available on the status and health of 
monarchs outside of the North American migratory populations or 
regarding the positive or negative influences acting upon these 
populations. Based on observations of the species throughout its range, 
69 of the 90 countries, islands, and island groups are currently 
extant. Monarch presence within the remaining 21 countries, islands, 
and island groups has not been confirmed since 2000, but with no 
evidence of extirpation, they are all presumed extant. Furthermore, we 
grouped occurrences into 31 populations. Of the 29 populations outside 
of North America, 25 are confirmed extant and the remaining 4 are 
presumed extant (Service 2024a, pp. 40-42). We were not able to further 
assess the level of resiliency of these populations.
Current Resiliency, Redundancy, and Representation
    The species' redundancy is evident through its confirmed or 
presumed presence in all 90 of the countries, islands, and island 
groups where it occurred historically or to where it has dispersed. The 
species' adaptive capacity (representation) is evident through its 
presence over a large geographical range made up of 31 known 
populations (2 North American migratory populations and 29 nonmigratory 
or dispersed populations) where the climatic conditions and habitat 
vary widely. The species' resiliency varies between populations, with 
the estimated probability of extinction for the eastern migratory North 
American population at less than 10 percent in 10 years and 60 to 68 
percent for the western migratory North American population in 10 
years. For monarchs outside of the North American migratory 
populations, 69 of the 90 countries, islands, and island groups are 
considered currently extant, although we were not able to further 
assess the level of resiliency of these populations.

Future Condition

Future Scenarios and Catastrophic Events
North American Migratory Populations
    To assess the future condition of monarch populations, we organized 
the key factors driving monarch population dynamics into six 
categories: (1) milkweed availability, (2) breeding nectar 
availability, (3) migration nectar availability, (4) overwintering 
habitat availability, (5) climate change effects, and (6) insecticide 
exposure. We then forecasted plausible increases and/or decreases, as 
appropriate, for each of these influences, using the best available 
information, including scientific literature and expert input. We also 
included conservation efforts outlined in large-scale monarch 
conservation plans, such as the MAFWA Strategy and WAFWA Plan. We did 
not evaluate these plans under the Policy for Evaluating Conservation 
Efforts (68 FR 15100; March 28, 2003) because these formalized 
conservation efforts have been implemented. Next, we combined the upper 
plausible limit and the lower plausible limit for each influence 
(changes in milkweed, nectar, and overwintering habitat; climate 
change; and insecticides) to form composite plausible best case and 
plausible worst case scenarios, respectively. Lastly, we incorporated 
these scenarios into the population models described in the Current 
Condition section, and forecasted population numbers to 60 years to 
determine the probability of extinction for both the eastern and 
western migratory North American populations to 2080 (Service 2024a, 
tables 6.1 and 6.2, pp. 45-47).
    We also evaluated several potential events to determine if they 
were of sufficient magnitude and severity to cause a population 
collapse (i.e., a catastrophic event). We determined that extreme storm 
events and widespread

[[Page 100678]]

drought have sufficient potential to pose a catastrophic risk to the 
eastern population, and widespread drought and co-occurrence of poor 
environmental conditions and low population abundance have sufficient 
potential to pose a catastrophic risk to the western population.
Dispersed Nonmigratory Populations
    Due to a lack of information on current influences, we were unable 
to forecast future scenarios for the populations outside of eastern and 
western North America. However, we identified two potential 
catastrophic events, both of which are effects of climate change: sea 
level rise and lethal high temperatures.
Future Conditions
Eastern North American Population
    Under both best and worst case scenarios described above, the 
population continues to decline ([lambda] < 1). The greatest impact on 
the population occurs during the first 20 years for both scenarios; we 
had a slight increase in the growth rate from the current value under 
the best case scenario and a decrease of 4.5 percent under the worst 
case scenario. As expected under a declining growth rate, the 
probability of extinction increases over time (Service 2024a, p. 64). 
In 30 years, probability of extinction ranges from 24 to 46 percent. In 
60 years, the probability of extinction for the eastern North American 
population ranges from 56 to 74 percent.
    We were unable to incorporate direct effects from increasing 
temperatures and catastrophic risks into the population models, so we 
qualitatively discuss the implications of these factors on the future 
condition of the population. We evaluated the changes in the spatial 
extent and number of days with projected temperatures above lethal and 
sublethal thermal thresholds during critical time periods in monarch 
migration (Service 2024a, pp. 120-122). We assessed these changes under 
two future scenarios, using Representative Concentration Pathways 
(RCPs). RCPs reflect different levels of greenhouse gas emissions and 
the resulting climate change scenarios (IPCC 2014, p. 57). We used 
RCP4.5 and RCP8.5 scenarios projected to 2069 (Service 2024a, p. 122). 
Under the RCP4.5 scenario, both the spatial extent and the average 
number of days above 38 [deg]C (100 [deg]F) (the threshold for 
sublethal effects and moderate reductions in survival) are projected to 
markedly increase throughout much of the range, including the southern 
and northeastern portions of the eastern North American monarch 
breeding range. Although in the northcentral area of the breeding 
range, there is a projected decrease in spatial extent and the average 
number of days above 38 [deg]C (100 [deg]F). Under the RCP8.5 scenario, 
both the spatial extent and the average number of days above 38 [deg]C 
(100 [deg]F) have large increases throughout the entirety of the 
breeding range. The spatial extent and average number of days above 42 
[deg]C (107.6 [deg]F) (the lethal threshold) are projected to increase 
dramatically in the southern U.S. during the same period under both 
scenarios. Given these results, monarch reproductive success and 
survival rates of the first generation of monarchs coming from the 
wintering grounds are likely to decline, although the extent to which 
these rates will decline is unknown.
    Similarly, given the projected population decline described above, 
the eastern population will be increasingly vulnerable to catastrophic 
losses due to extreme storm events at the overwintering grounds and 
widespread droughts during the breeding season and along the migratory 
route. Although we cannot quantify this increased risk, the longer the 
eastern population remains at low population abundance, the more likely 
it is that catastrophic losses will occur and the greater the 
extinction risk for the eastern population.
Western North American Population
    Under both scenarios, the population continues to decline ([lambda] 
< 1). Under the best case scenario, monarchs have a slight increase in 
the growth rate from the current value; however, even with an increase, 
this was still a declining growth rate. Under the worst case scenario, 
the growth rate decreased to a lower rate than the current rate. As 
would be expected with a declining growth rate, the probability of 
extinction increases over time (Service 2024a, p. 66). In 30 years, 
probability of extinction ranges from 92 percent to 95 percent. By year 
60, the probability of extinction reaches 99 percent for the western 
North American population.
    Under the RCP4.5 scenario, increases are projected for the average 
numbers of days above 38 [deg]C (100.4 [deg]F) (38 percent) and above 
42 [deg]C (107.6 [deg]F) (11 percent). Given this, monarch reproductive 
success and survival rates are likely to decline, although the extent 
to which these rates will decline is unknown.
    Similarly, given the projections of monarch health described above, 
the western population is vulnerable to catastrophic losses due to both 
widespread drought events and the co-occurrence of poor environmental 
conditions and low population abundance. The risk of extinction due to 
these events increases the longer the population remains at the current 
low abundances.
Dispersed Nonmigratory Populations
    We qualitatively assessed the impact due to predicted climate 
change effects. Fifteen of the 29 populations are classified as being 
``at risk'' due to threats associated with climate change (6 due to sea 
level rise and 9 due to unsuitably high temperatures). The populations 
susceptible to sea level rise (Johnston Atoll, Kiribati, Marshall 
Islands, Nauru, Tokelau, and Tuvalu) are at risk of losing at least 
some of their monarch habitat; thus, redundancy could decrease with the 
loss of those areas. However, the best available information does not 
indicate if populations at risk to high temperatures will lose all or 
just a portion of their monarch habitat; thus, they may continue to 
contribute to redundancy. Each of the populations at risk due to sea 
level rise contains a single country, island, or island group. 
Therefore, in the dispersed nonmigratory populations the species will 
continue to have redundancy through continued presence in an estimated 
84 of the 90 countries, islands, and island groups where it occurred 
historically or to where it has dispersed. We anticipate the species 
will continue to have adaptive capacity (representation) through its 
presence over a large geographical range where the climatic conditions 
and habitat vary widely.
Future Resiliency, Redundancy, and Representation
    Both the eastern and western migratory North American populations 
become more vulnerable to catastrophic events (e.g., extreme storms at 
the overwintering habitat) into the future resulting in lower 
redundancy for the species. Under plausible climate change scenarios, 
monarch butterflies will be exposed to unsuitably high temperatures for 
more days each year and over larger areas of their range in North 
America. Outside of the two North American migratory populations, 15 of 
the 29 nonmigratory or dispersed populations are at risk in the future 
due to threats associated with climate change (6 due to sea level rise 
and 9 due to unsuitably high temperatures). The populations susceptible 
to sea level rise are at risk of losing at least some of their monarch 
habitat; thus, redundancy could decrease with the loss of those areas. 
Rangewide, the species is likely to maintain considerable redundancy 
and adaptive capacity (representation)

[[Page 100679]]

through continued presence in an estimated 84 of the 90 countries, 
islands, and island groups where it occurred historically or to where 
it has dispersed. Despite uncertainties about resiliency at the 
nonmigratory and dispersed populations, the widespread distribution of 
monarch populations indicates that the species has low risk of becoming 
extirpated from multiple locations should a large-scale catastrophic 
event occur; thus, it is unlikely that a single catastrophic event 
would affect the entire species across its large range.
    In the future, the resiliency of the eastern and western North 
American migratory populations will continue to decline. The estimated 
probability of extinction for the eastern migratory North American 
population is 56-74 percent in 60 years and greater than 99 percent for 
the western migratory North American population in 60 years.

Determination of Monarch Butterfly Status

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species meets the definition of an endangered species or a 
threatened species. The Act defines an ``endangered species'' as a 
species in danger of extinction throughout all or a significant portion 
of its range, and a ``threatened species'' as a species likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range. The Act requires that we 
determine whether a species meets the definition of an endangered 
species or a threatened species because of any of the following 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence.

Status Throughout All of Its Range

    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we determined that the primary threats affecting the monarch 
and its habitat are the ongoing impacts from loss and degradation of 
breeding, migratory, and overwintering habitat (from past conversion of 
grasslands and shrublands to agriculture and widespread use of 
herbicides; logging/thinning at overwintering sites in Mexico; urban 
development, senescence, and incompatible management of overwintering 
sites in California; and drought) (Factor A); exposure to insecticides 
(Factor E); and effects of climate change (Factor E).
    While the monarch butterfly is historically native to North America 
with migratory and nonmigratory populations, monarchs have dispersed 
via human assistance from North America in the past two centuries and 
their range now includes populations throughout 90 countries, islands, 
and island groups where milkweed was already present or introduced. 
Populations exist in Central and South America, Australia, New Zealand, 
islands of the Pacific and Caribbean, and elsewhere (see Service 2024a, 
pp. 41-42). The primary threats have been affecting the resiliency of 
the eastern and western North American migratory populations over the 
last 20 years, and both populations now have lower abundances and 
declining population growth rates. However, in its current condition, 
the probability of extinction of the eastern migratory population is 
less than 10 percent over the next 10 years. The probability of 
extinction of the western migratory population over that same time 
period is higher (60-68 percent).
    For monarchs outside of the two North American migratory 
populations, 69 of the 90 countries, islands, and island groups are 
considered currently extant. Monarch presence within the remaining 21 
countries, islands, and island groups has not been confirmed since 
2000, but the best available information does not indicate they are 
extirpated, and thus they are all presumed extant. Of the 29 
populations outside of North America, 25 are confirmed extant, and the 
remaining 4 are presumed extant (see Service 2024a, pp. 40-42). 
Although we were not able to further assess the level of resiliency of 
these 29 nonmigratory or dispersed populations, the species' redundancy 
is evident through its confirmed or presumed presence in all 90 of the 
countries, islands, and island groups where it occurred historically or 
to where it has dispersed. The species' adaptive capacity is evident 
through its presence over a large geographical range made up of 31 
known populations (2 North American migratory populations and 29 
nonmigratory or dispersed populations) where the climatic conditions 
and habitat vary widely. Despite uncertainties about resiliency at some 
of the locations (i.e., the 29 nonmigratory and dispersed populations), 
the number and distribution of populations at multiple locations makes 
it unlikely that a single catastrophic event would affect the entire 
species across its large range. Based on the best scientific and 
commercial data available, we conclude that the monarch butterfly is 
not currently in danger of extinction throughout all of its range.
    While the monarch butterfly is not currently in danger of 
extinction, under the Act we must determine whether the species is 
likely to become in danger of extinction within the foreseeable future 
throughout all of its range (i.e., whether the species warrants listing 
as threatened). In the foreseeable future, we anticipate the status of 
the eastern and western North American migratory populations will 
continue to decline due to the primary threats listed above. The 
probability of extinction of the eastern migratory population in the 
foreseeable future, which is 60 years, is estimated to be 56-74 
percent, and the probability of extinction for the western migratory 
population is estimated to be 99 percent. Outside of the two North 
American migratory populations, we found that 15 of the 29 nonmigratory 
or dispersed populations are at risk in the future due to threats 
associated with climate change (6 due to sea level rise and 9 due to 
unsuitably high temperatures). The populations susceptible to sea level 
rise are at risk of losing at least some of their monarch habitat; 
thus, redundancy could decrease with the loss of those areas. However, 
the best scientific and commercial data available do not indicate if 
populations susceptible to high temperatures are at risk of losing all 
or just a portion of their monarch habitat; thus, they may continue to 
contribute to redundancy. Therefore, rangewide, we conclude that the 
species is likely to maintain considerable redundancy through continued 
presence in an estimated 84 of the 90 countries, islands, and island 
groups where it occurred historically or to where it has dispersed.
    We find that the species will continue to have adaptive capacity 
(representation) through its presence over a large geographical range 
where the climatic conditions and habitat vary widely. Despite 
uncertainties about resiliency at the nonmigratory and dispersed 
populations, the widespread distribution of monarch populations 
indicates that the species has low risk of becoming extirpated from 
multiple locations should a large-scale catastrophic event occur; thus, 
it is unlikely that a single catastrophic event would affect the entire 
species across its large range. Thus, after assessing the best 
available information, we conclude that the monarch butterfly is not 
likely

[[Page 100680]]

to become in danger of extinction within the foreseeable future 
throughout all of its range.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
within the foreseeable future throughout all or a significant portion 
of its range. The court in Center for Biological Diversity v. Everson, 
435 F. Supp. 3d 69 (D.D.C. 2020) (Everson), vacated the provision of 
the Final Policy on Interpretation of the Phrase ``Significant Portion 
of Its Range'' in the Endangered Species Act's Definitions of 
``Endangered Species'' and ``Threatened Species'' (hereafter ``Final 
Policy''; 79 FR 37578, July 1, 2014) that provided if the Services 
determine that a species is threatened throughout all of its range, the 
Services will not analyze whether the species is endangered in a 
significant portion of its range.
    Therefore, we proceed to evaluating whether the species is 
endangered in a significant portion of its range--that is, whether 
there is any portion of the species' range for which both (1) the 
portion is significant; and (2) the species is in danger of extinction 
in that portion. Depending on the case, it might be more efficient for 
us to address the ``significance'' question or the ``status'' question 
first. We can choose to address either question first. Regardless of 
which question we address first, if we reach a negative answer with 
respect to the first question that we address, we do not need to 
evaluate the other question for that portion of the species' range.
    Following the court's holding in Everson, we now consider whether 
there are any significant portions of the species' range where the 
species is in danger of extinction now (i.e., endangered). In 
undertaking this analysis for the monarch butterfly, we choose to 
address the significance question first. We assessed whether any 
portions of the species' range are biologically significant by 
considering them in terms of each portion's contribution to resiliency, 
redundancy, or representation of the species as a whole.
    The monarch butterfly is historically native to North America, and, 
as discussed above, it now occurs in nonnative or naturalized 
populations throughout 90 countries, islands, and island groups, 
including parts of Central and South America, Australia, New Zealand, 
islands of the Pacific and Caribbean, and elsewhere (see Service 2024a, 
pp. 41-42). To identify portions for evaluation, we considered these 
geographic areas independently and in various combinations to identify 
those which are biologically meaningful to the species.
    We found that monarch habitat in North America represents a 
significant portion of the range. This geographical portion is 
significant because it is physically large, representing a large 
proportion of the species' range, and has unique habitat features that 
support monarch migration. The monarch's North American portion of the 
range covers approximately 2.8 billion ac (1.1 billion ha), encompasses 
an estimated 62 percent of the species' geographic range, and 
represents a vast majority of monarch butterflies worldwide. The 
portion is the ancestral source for migratory monarchs in North America 
and includes nonmigratory monarchs that have descended from migratory 
monarchs. The best available information indicates that the total 
number of nonmigratory monarchs in North America appears to be quite 
small relative to the North American migratory populations that 
overwinter in Mexico and California. The portion contains the entirety 
of breeding, migratory, and overwintering habitats used by monarchs in 
the eastern and western migratory populations. The monarchs within 
eastern and western North America have continued interchange between 
the two populations contributing to low genetic differentiation and 
forming an admixed population (Lyons et al. 2012, p. 3441; Talla et al. 
2020, p. 2573; Freedman et al. 2021, pp. 7-8). These habitats in North 
America are unique because they facilitate massive annual range 
expansions during the breeding season. Temporary, seasonal resources 
allow monarchs to escape habitats as they become more heavily infected 
with diseases like OE (Bartel et al. 2011, entire). This seasonal 
movement also facilitates migratory culling where smaller and unhealthy 
individuals are removed from the breeding population because they are 
unable to survive long-distance migration (Bartel et al. 2011, entire; 
Majewska et al. 2021, p. 788). Years with favorable conditions across 
the broad and spatially diffuse breeding habitat in this portion have 
the potential to support rapid migratory monarch population increases 
(Yang et al. 2022, p. 20), which is important for population 
resiliency.
    We also considered eastern and western North America as individual 
portions. The portion of North America used by the eastern migratory 
population is the largest area used by a single population in terms of 
geographic size. It represents roughly 43 percent of the species' 
global range. The portion of North America used by the western 
migratory population encompasses roughly 18 percent of the species' 
global range. Individually, neither portion makes up a large enough 
geographic area relative to the remainder of the range. Both migratory 
populations require sufficient quality and quantity of milkweed and 
nectar resources, suitable habitat for overwintering, and adequate 
connectivity and aligned phenology. Both of these portions provide the 
resources and space needed to facilitate the massive annual migration 
and range expansions necessary to maintain the viability of the 
migratory populations, as described above. However, because these 
portions individually constitute smaller areas, they were not 
determined to be significant individually when compared to the portion 
encompassing both North American migratory populations.
    Having determined that North America is significant for the 
purposes of evaluating a significant portion of the monarch's range, we 
then proceeded to address the status question by examining the threats 
in that portion to determine if the species is endangered or threatened 
in that portion. The statutory difference between an endangered species 
and a threatened species is the timeframe in which the species becomes 
in danger of extinction; an endangered species is in danger of 
extinction while a threatened species is likely to become so (i.e., 
endangered) within the foreseeable future. As discussed under Status 
Throughout All of Its Range, above, the primary current threats to the 
monarch butterfly are the ongoing impacts from loss and degradation of 
breeding, migratory, and overwintering habitat (from past conversion of 
grasslands to agriculture; widespread use of herbicides; logging/
thinning at overwintering sites in Mexico; urban development, 
senescence, and incompatible management of overwintering sites in 
California; and drought), exposure to insecticides, and effects of 
climate change. We examined those threats along with the effects from 
disease and cumulative effects, and we considered whether conservation 
efforts and regulatory mechanisms ameliorated any of the effects.
    Many of these factors and threats influence the monarch butterfly 
rangewide; however, because we identified the North America portion as 
being significant, we considered whether the threats are causing 
monarchs in the portion to have a different status than the remainder 
of

[[Page 100681]]

the range. As discussed above, this portion contains the eastern and 
western North American migratory populations. For the two migratory 
populations, we estimated the probability of the population abundance 
reaching the point at which extinction is inevitable for each 
population. In its current condition, the eastern migratory population 
has a probability of extinction of less than 10 percent over the next 
10 years. The western migratory population has a higher risk of 
extinction due to current threats, with a probability of extinction of 
60-68 percent over the next 10 years. The probability of extinction 
estimates do not account for risks from catastrophic events; however, 
we do not anticipate these effects to significantly increase extinction 
risk of North American migratory monarchs in the near term. Based on 
the eastern migratory population's level of resiliency in the near term 
and because monarchs are distributed across a broad geographic area 
contributing to the redundancy and representation of the species in the 
portion, we concluded that the monarch butterfly in North America is 
not in danger of extinction within this significant portion of its 
range and does not meet the definition of an endangered species.
    We next considered whether the monarch butterfly is likely to 
become an endangered species within the foreseeable future in the North 
America portion (i.e., if it meets the Act's definition of a threatened 
species). Looking across the range of future conditions for which we 
can make reasonably reliable predictions, the probability of extinction 
for the eastern migratory population is estimated to be 24-46 percent 
in 30 years and 56-74 percent in 60 years. The probability of 
extinction for the western migratory population is estimated to be 92-
95 percent in 30 years and reaches 99 percent in 60 years. These 
probability of extinction estimates incorporate the primary factors 
that influence the populations' resiliency, including the ongoing 
impacts of availability of milkweed and nectar resources (losses as 
well as gains from conservation efforts), loss and degradation of 
overwintering habitat, insecticides, and effects of climate change. In 
addition to being affected by these factors, both the eastern and 
western migratory populations become more vulnerable to catastrophic 
events (e.g., extreme storms at the overwintering habitat) into the 
future. Under plausible climate change scenarios, monarch butterflies 
will be exposed to unsuitably high temperatures for more days each year 
and over larger areas of their range in North America.
    The best available scientific and commercial information indicates 
nonmigratory monarch populations in North America are very small 
compared to the size of the two migratory populations. In our 
assessment of the threats, we found that the three nonmigratory 
populations in Florida, the Caribbean, and countries in Central America 
are at risk due to unsuitably high temperatures associated with climate 
change. There is potential for nonmigratory monarch populations in 
North America to be demographic sinks (see Crone and Schultz 2021, p. 
1536), requiring continual influxes of monarchs from migratory 
populations to sustain them. Therefore, the status of nonmigratory 
monarchs in the North American portion is also in decline.
    After assessing the best scientific and commercial data available, 
we found that migratory monarch butterflies in North America, which 
represent the vast majority of monarch butterflies worldwide, have a 
high likelihood of becoming extirpated in 60 years. Therefore, we 
conclude that the monarch butterfly is likely to become in danger of 
extinction within the foreseeable future throughout North America. 
Therefore, having determined that the North America portion is both (1) 
significant; and (2) likely to become in danger of extinction within 
the foreseeable future, we conclude that the monarch butterfly is in 
danger of extinction within the foreseeable future within a significant 
portion of its range. This is consistent with the courts' holdings in 
Desert Survivors v. U.S. Department of the Interior, 321 F. Supp. 3d 
1011, 1070-74 (N.D. Cal. 2018) and Center for Biological Diversity v. 
Jewell, 248 F. Supp. 3d, 946, 959 (D. Ariz. 2017).

Determination of Status

    Based on the best scientific and commercial data available, we 
determine that the monarch butterfly meets the Act's definition of a 
threatened species. Therefore, we propose to add the monarch butterfly 
as a threatened species to the List of Endangered and Threatened 
Wildlife in 50 CFR 17.11(h) in accordance with sections 3(20) and 
4(a)(1) of the Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition as a listed 
species, planning and implementation of recovery actions, requirements 
for Federal protection, and prohibitions against certain practices. 
Recognition through listing results in public awareness, and 
conservation by Federal, State, Tribal, and local agencies, foreign 
governments, private organizations, and individuals. The Act encourages 
cooperation with the States and other countries and calls for recovery 
actions to be carried out for listed species. The protection required 
by Federal agencies, including the Service, and the prohibitions 
against certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Section 4(f) of the Act calls for the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The goal of this process is to restore listed 
species to a point where they are secure, self-sustaining, and 
functioning components of their ecosystems.
    The recovery planning process begins with development of a recovery 
outline made available to the public soon after a final listing 
determination. The recovery outline guides the immediate implementation 
of urgent recovery actions while a recovery plan is being developed. 
Recovery teams (composed of species experts, Federal and State 
agencies, nongovernmental organizations, and stakeholders) may be 
established to develop and implement recovery plans. The recovery 
planning process involves the identification of actions that are 
necessary to halt and reverse the species' decline by addressing the 
threats to its survival and recovery. The recovery plan identifies 
recovery criteria for review of when a species may be ready for 
reclassification from endangered to threatened (``downlisting'') or 
removal from protected status (``delisting''), and methods for 
monitoring recovery progress. Recovery plans also establish a framework 
for agencies to coordinate their recovery efforts and provide estimates 
of the cost of implementing recovery tasks. Revisions of the plan may 
be done to address continuing or new threats to the species, as new 
substantive information becomes available. The recovery outline, draft 
recovery plan, final recovery plan, and any revisions will be available 
on our website as they are completed (https://www.fws.gov/program/endangered-species), or from our Midwest Region

[[Page 100682]]

Headquarters (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    To improve future conditions so that the monarch migratory 
populations stabilize and grow, we need to (1) achieve a significant 
increase in the availability of milkweed and nectar plants in monarch 
breeding and migratory areas; (2) protect and enhance overwintering 
habitat; (3) avoid and minimize impacts to monarchs and their habitat 
from insecticides and herbicides; and (4) maintain public support for 
the conservation of monarch butterflies. Because of the monarch 
butterfly's general habitat use and wide distribution, all sectors of 
society, including the general public, have an opportunity to 
participate in a broad range of conservation efforts throughout the 
species' range.
    If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost-share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. In addition, 
pursuant to section 6 of the Act, the States of Alabama, Arizona, 
Arkansas, California, Colorado, Connecticut, Delaware, Florida, 
Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, 
Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, 
Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New 
Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, 
Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South 
Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West 
Virginia, Wisconsin, and Wyoming; the U.S. Commonwealths of the 
Northern Mariana Islands and Puerto Rico; and the U.S. Territories of 
American Samoa, Guam, and the U.S. Virgin Islands would be eligible for 
Federal funds to implement management actions that promote the 
protection or recovery of the monarch butterfly. Information on our 
grant programs that are available to aid species recovery can be found 
at: https://www.fws.gov/service/financial-assistance.
    Although the monarch butterfly is only proposed for listing under 
the Act at this time, please let us know if you are interested in 
participating in recovery efforts for this species. Additionally, we 
invite you to submit any new information on this species whenever it 
becomes available and any information you may have for recovery 
planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7 of the Act is titled, ``Interagency Cooperation,'' and it 
mandates all Federal action agencies to use their existing authorities 
to further the conservation purposes of the Act and to ensure that 
their actions are not likely to jeopardize the continued existence of 
listed species or adversely modify critical habitat. Regulations 
implementing section 7 are codified at 50 CFR part 402.
    Section 7(a)(1) directs all Federal agencies, in consultation with 
the Secretary, to utilize their authorities to carry out ``programs for 
the conservation of endangered and threatened species.'' This provision 
provides an affirmative and broad mandate to all agencies to take 
action to conserve threatened and endangered species. This section 
affords broad discretion to agencies on the measures they undertake as 
part of their conservation programs within their existing authorities, 
and robust section 7(a)(1) programs may assist Federal agencies with 
their obligations under section 7(a)(2). Section 7(a)(2) states that 
each Federal action agency shall, in consultation with the Secretary, 
ensure that any action they authorize, fund, or carry out is not likely 
to jeopardize the continued existence of a listed species or result in 
the destruction or adverse modification of designated critical habitat. 
Each Federal agency shall review its action at the earliest possible 
time to determine whether it may affect listed species or critical 
habitat. If a determination is made that the action may affect listed 
species or critical habitat, formal consultation is required (50 CFR 
402.14(a)), unless the Service concurs in writing that the action is 
not likely to adversely affect listed species or critical habitat. At 
the end of a formal consultation, the Service issues a biological 
opinion, containing its determination of whether the Federal action is 
likely to result in jeopardy or adverse modification.
    In contrast, section 7(a)(4) of the Act requires Federal agencies 
to confer with the Service on any action which is likely to jeopardize 
the continued existence of any species proposed to be listed under the 
Act or result in the destruction or adverse modification of critical 
habitat proposed to be designated for such species. Although the 
conference procedures are required only when an action is likely to 
result in jeopardy or adverse modification, action agencies may 
voluntarily confer with the Service on actions that may affect species 
proposed for listing or critical habitat proposed to be designated. In 
the event that the subject species is listed or the relevant critical 
habitat is designated, a conference opinion may be adopted as a 
biological opinion and serve as compliance with section 7(a)(2) of the 
Act.
    Examples of discretionary actions for the monarch butterfly that 
may be subject to conference and consultation procedures under section 
7 are management of Federal lands administered by the Army Corps of 
Engineers, Bureau of Land Management, Department of Defense (DoD), 
National Park Service, Office of Surface Mining, and U.S. Forest 
Service as well as actions that require a Federal permit (such as a 
permit from the U.S. Army Corps of Engineers under section 404 of the 
Clean Water Act (33 U.S.C. 1251 et seq.)) or actions funded by Federal 
agencies such as the Federal Highway Administration, Federal Aviation 
Administration, U.S. Department of Agriculture, or the Federal 
Emergency Management Agency. We also anticipate conferencing or 
consultation by the EPA as part of their pesticide registration actions 
under FIFRA. Federal actions not affecting listed species or critical 
habitat--and actions on State, Tribal, local, or private lands that are 
not federally funded, authorized, or carried out by a Federal agency--
do not require section 7 consultation. Federal agencies should 
coordinate with the local Service Field Office or Midwest Region 
Headquarters (see FOR FURTHER INFORMATION CONTACT) with any specific 
questions on section 7 consultation and conference requirements.

II. Protective Regulations Under Section 4(d) of the Act

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the Secretary shall issue such regulations as she deems 
necessary and advisable to provide for the conservation of species 
listed as threatened species. Conservation is defined in the Act to 
mean the use of all methods and procedures which are

[[Page 100683]]

necessary to bring any endangered species or threatened species to the 
point at which the measures provided pursuant to the Act are no longer 
necessary. Additionally, the second sentence of section 4(d) of the Act 
states that the Secretary may by regulation prohibit with respect to 
any threatened species any act prohibited under section 9(a)(1), in the 
case of fish or wildlife, or section 9(a)(2), in the case of plants. 
With these two sentences in section 4(d), Congress delegated broad 
authority to the Secretary to determine what protections would be 
necessary and advisable to provide for the conservation of threatened 
species, and even broader authority to put in place any of the section 
9 prohibitions, for a given species.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld, as a valid 
exercise of agency authority, rules developed under section 4(d) that 
included limited prohibitions against takings (see Alsea Valley 
Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington 
Environmental Council v. National Marine Fisheries Service, 2002 WL 
511479 (W.D. Wash. 2002)). Courts have also upheld 4(d) rules that do 
not address all of the threats a species faces (see State of Louisiana 
v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted in the legislative 
history when the Act was initially enacted, ``once an animal is on the 
threatened list, the Secretary has an almost infinite number of options 
available to [her] with regard to the permitted activities for those 
species. [She] may, for example, permit taking, but not importation of 
such species, or [she] may choose to forbid both taking and importation 
but allow the transportation of such species'' (H.R. Rep. No. 412, 93rd 
Cong., 1st Sess. 1973).
    The provisions of this species' proposed protective regulations 
under section 4(d) of the Act are one of many tools that we would use 
to promote conservation of the monarch butterfly by encouraging 
creation and management of habitat in ways that address threats to the 
species and maintain public support for its conservation. To achieve a 
significant increase in the availability of milkweed and nectar plants 
in monarch breeding areas, we need to incentivize return of milkweed to 
large portions of the landscape where it is now nonexistent or where 
what remains is highly fragmented. Given that so much milkweed has been 
lost historically and that monarchs are impacted by the ongoing effects 
of this past habitat loss and degradation, we need an approach that 
encourages landowners to add milkweeds and nectar plants and implement 
actions to maintain them. Creation, enhancement, and maintenance of 
higher quality habitat by the public may lead to the temporary 
destruction of milkweed and nectar plants and incidental take of 
monarchs. Private landowner and general public support are crucial 
because the species is wide-ranging and needs broad conservation 
action, from small- to large-scale efforts, throughout its range. 
Conservation for the species can occur on land parcels ranging from 
quite small to very large, including gardens, parks, grasslands, 
agricultural areas, and more. Because of the monarch butterfly's 
general habitat use and wide distribution, all sectors of society, 
including the general public, have an opportunity to participate in a 
broad range of conservation efforts throughout the species' range. The 
proposed 4(d) rule allows for the general public to take action to 
participate in the recovery of monarchs without fear of unintentional 
violation for the Act. Public action is necessary for the conservation 
of the species.
    The proposed protective regulations would apply only if and when we 
make final the listing of the monarch butterfly as a threatened 
species. Nothing in 4(d) rules changes in any way the recovery planning 
provisions of section 4(f) of the Act, the consultation requirements 
under section 7 of the Act, or the ability of the Service to enter into 
partnerships for the management and protection of the monarch 
butterfly.
    As mentioned previously in Available Conservation Measures, section 
7(a)(2) of the Act requires Federal agencies, including the Service, to 
ensure that any action they authorize, fund, or carry out is not likely 
to jeopardize the continued existence of any endangered species or 
threatened species or result in the destruction or adverse modification 
of designated critical habitat of such species. In addition, even 
before the listing of any species or the designation of its critical 
habitat is finalized, section 7(a)(4) of the Act requires Federal 
agencies to confer with the Service on any agency action which is 
likely to jeopardize the continued existence of any species proposed to 
be listed under the Act or result in the destruction or adverse 
modification of critical habitat proposed to be designated for such 
species. These requirements are the same for a threatened species 
regardless of what is included in its 4(d) rule.
    Section 7 consultation is required for Federal actions that ``may 
affect'' a listed species regardless of whether take caused by the 
activity is prohibited or excepted by a 4(d) rule (under application of 
a ``blanket rule'' (for more information, see 89 FR 23919, April 5, 
2024) or a species-specific 4(d) rule). A 4(d) rule does not change the 
process and criteria for informal or formal consultations and does not 
alter the analytical process used for biological opinions or 
concurrence letters. For example, as with an endangered species, if a 
Federal agency determines that an action is ``not likely to adversely 
affect'' a threatened species, this will require the Service's written 
concurrence (50 CFR 402.13(c)). Similarly, if a Federal agency 
determinates that an action is ``likely to adversely affect'' a 
threatened species, the action will require formal consultation with 
the Service and the formulation of a biological opinion (50 CFR 
402.14(a)). Because consultation obligations and processes are 
unaffected by 4(d) rules, we may consider developing tools to 
streamline future intra-Service and interagency consultations for 
actions that result in forms of take that are not prohibited by the 
4(d) rule (but that still require consultation). These tools may 
include consultation guidance; streamlined, online consultation 
processes via the Service's digital project planning tool (Information 
for Planning and Consultation; https://ipac.ecosphere.fws.gov/); 
template language for biological opinions; or programmatic 
consultations. Nonetheless, section 7(a)(1) authority provides a great 
deal of unrealized potential in achieving recovery goals, and this 4(d) 
rule incentivizes agencies to fully utilize their authorities to design 
and implement conservation programs that meaningfully benefit monarch 
butterflies.

Provisions of the Proposed 4(d) Rule

    Exercising the Secretary's authority under section 4(d) of the Act, 
we have developed a proposed rule that is designed to address the 
monarch butterfly's conservation needs. As discussed previously in 
Summary of Biological Status and Threats, we have concluded that the 
monarch butterfly is likely to become in danger of extinction within 
the foreseeable future primarily due to the ongoing impacts of loss and 
degradation of breeding, migratory, and overwintering habitat (from 
past conversion of grasslands and shrublands to agriculture and 
widespread use of herbicides; logging/thinning at overwintering sites 
in Mexico; urban development, senescence, and

[[Page 100684]]

incompatible management of overwintering sites in California; and 
drought), exposure to insecticides, and effects of climate change. 
Section 4(d) requires the Secretary to issue such regulations as she 
deems necessary and advisable to provide for the conservation of each 
threatened species and authorizes the Secretary to include among those 
protective regulations any of the prohibitions that section 9(a)(1) of 
the Act prescribes for endangered species. We are not required to make 
a ``necessary and advisable'' determination when we apply or do not 
apply specific section 9 prohibitions to a threatened species (In re: 
Polar Bear Endangered Species Act Listing and 4(d) Rule Litigation, 818 
F. Supp. 2d 214, 228 (D.D.C. 2011) (citing Sweet Home Chapter of 
Communities for a Great Oregon v. Babbitt, 1 F.3d 1, 8 (D.C. Cir. 
1993), rev'd on other grounds, 515 U.S. 687 (1995))). Nevertheless, 
even though we are not required to make such a determination, we have 
chosen to be as transparent as possible and explain below why we find 
that, if finalized, the protections, prohibitions, and exceptions in 
this proposed rule as a whole satisfy the requirement in section 4(d) 
of the Act to issue regulations deemed necessary and advisable to 
provide for the conservation of the monarch butterfly.
    The protective regulations we are proposing for the monarch 
butterfly incorporate prohibitions from section 9(a)(1) to address the 
threats to the species. The prohibitions of section 9(a)(1), and the 
implementing regulations codified at 50 CFR 17.21, make it illegal for 
any person subject to the jurisdiction of the United States to commit, 
to attempt to commit, to solicit another to commit or to cause to be 
committed any of the following acts with regard to any endangered 
wildlife: (1) import into or export from, the United States; (2) take 
(which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect, or to attempt to engage in any such conduct) 
within the United States, within the territorial sea of the United 
States, or on the high seas; (3) possess, sell, deliver, carry, 
transport, or ship, by any means whatsoever, any such wildlife that has 
been taken illegally; (4) deliver, receive, carry, transport, or ship 
in interstate or foreign commerce, by any means whatsoever and in the 
course of commercial activity; or (5) sell or offer for sale in 
interstate or foreign commerce. This protective regulation includes all 
these prohibitions because the eastern and western North America 
monarch populations are at risk of extinction within the foreseeable 
future and putting these prohibitions in place will help to prevent 
further declines, slow the rate of decline, and decrease negative 
effects from other ongoing or future threats.
    In particular, this proposed 4(d) rule would provide for the 
conservation of the monarch butterfly by prohibiting the following 
activities, unless they fall within specific exceptions or are 
otherwise authorized or permitted: importing or exporting; take; 
possession and other acts with unlawfully taken specimens; delivering, 
receiving, carrying, transporting, or shipping in interstate or foreign 
commerce in the course of commercial activity; or selling or offering 
for sale in interstate or foreign commerce. We are proposing to 
prohibit these activities in the contiguous United States, Puerto Rico, 
and the U.S. Virgin Islands. We are not proposing to prohibit these 
activities in Hawaii or other U.S. Territories because these areas are 
outside the historical range of the species and monarchs in these areas 
will not contribute to recovery of the species in North America. We are 
also not proposing to prohibit these activities in Alaska because the 
species does not occur there. Further, import and interstate movement 
of monarch butterflies is regulated by the U.S. Department of 
Agriculture, and monarchs may not be transported to Hawaii, Alaska, or 
any of the U.S. Territories under existing regulations in 7 CFR part 
330.
    Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, or collect, or to attempt to engage in any 
such conduct. Some of these provisions have been further defined in 
regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by 
direct and indirect impacts, intentionally or incidentally. Regulating 
take would help to preserve the species' migratory populations, slow 
their rates of decline, and decrease synergistic, negative effects from 
other ongoing or future threats. Therefore, we propose to prohibit take 
of the monarch butterfly, except for take resulting from those actions 
and activities specifically excepted by the 4(d) rule.
    Exceptions to the prohibition on take would include all the general 
exceptions to the prohibition on take of endangered wildlife, as set 
forth in 50 CFR 17.21 and additional exceptions, as described below.
    Despite these prohibitions regarding threatened species, we may 
under certain circumstances issue permits to carry out one or more 
otherwise-prohibited activities, including those described above. The 
regulations that govern permits for threatened wildlife state that the 
Director may issue a permit authorizing any activity otherwise 
prohibited with regard to threatened species. These include permits 
issued for the following purposes: for scientific purposes, to enhance 
propagation or survival, for economic hardship, for zoological 
exhibition, for educational purposes, for incidental taking, or for 
special purposes consistent with the purposes of the Act (50 CFR 
17.32). The statute also contains certain exemptions from the 
prohibitions, which are found in sections 9 and 10 of the Act.
    In addition, to further the conservation of the species, any 
employee or agent of the Service, any other Federal land management 
agency, the National Marine Fisheries Service, a State conservation 
agency, or a federally recognized Tribe, who is designated by their 
agency or Tribe for such purposes, may, when acting in the course of 
their official duties, take threatened wildlife without a permit if 
such action is necessary to: (i) Aid a sick, injured, or orphaned 
specimen; or (ii) dispose of a dead specimen; or (iii) salvage a dead 
specimen that may be useful for scientific study; or (iv) remove 
specimens that constitute a demonstrable but nonimmediate threat to 
human safety, provided that the taking is done in a humane manner. Such 
taking may involve killing or injuring only if it has not been 
reasonably possible to eliminate such threat by live-capturing and 
releasing the specimen unharmed, in an appropriate area.
    We recognize the special and unique relationship that we have with 
our State natural resource agency partners in contributing to 
conservation of listed species. State agencies often possess scientific 
data and valuable expertise on the status and distribution of 
endangered, threatened, and candidate species of wildlife and plants. 
State agencies, because of their authorities and their close working 
relationships with local governments and landowners, are in a unique 
position to assist us in implementing all aspects of the Act. In this 
regard, section 6 of the Act provides that we must cooperate to the 
maximum extent practicable with the States in carrying out programs 
authorized by the Act. Therefore, any qualified employee or agent of a 
State conservation agency that is a party to a cooperative agreement 
with us in accordance with section 6(c) of the Act, who is designated 
by his or her agency for such purposes, would be able to conduct 
activities designed to conserve monarch butterflies that may result in

[[Page 100685]]

otherwise prohibited take without additional authorization.
    The main threats affecting the two North American migratory 
populations of monarch butterflies are the ongoing impacts from loss 
and degradation of breeding, migratory, and overwintering habitat (from 
past conversion of grasslands and shrublands to agriculture and 
widespread use of herbicides; logging/thinning at overwintering sites 
in Mexico; urban development, senescence; and incompatible management 
of overwintering sites in California; and drought), exposure to 
insecticides, and effects of climate change. To improve future 
conditions so that the monarch migratory populations stabilize and 
grow, we need to (1) achieve a significant increase in the availability 
of milkweed and nectar plants in monarch breeding and migratory areas; 
(2) protect and enhance overwintering habitat; (3) avoid and minimize 
impacts to monarchs and their habitat from insecticides and herbicides; 
and (4) maintain public support for the conservation of monarch 
butterflies.
    The proposed 4(d) rule would also provide for the conservation of 
the species by allowing exceptions that incentivize conservation 
actions or that, while they may have some minimal level of take of the 
monarch butterfly, are not expected to rise to the level that would 
have a negative impact (i.e., would have only de minimis impacts) on 
the species' conservation. The proposed exceptions to these 
prohibitions include take resulting from activities conducted for the 
benefit of monarch butterflies or with only de minimis impacts that may 
maintain, enhance, remove, or establish milkweed and nectar plants 
within the breeding and migratory range; implementation of a 
comprehensive conservation plan developed by or in coordination with a 
State agency or implementation of a conservation program developed by a 
Federal agency; maintenance or improvement of monarch overwintering 
habitat in the United States consistent with a site-specific Service-
approved Overwintering Site Land Management Plan; monarch mortality due 
to vehicle strikes; small-scale (250 or fewer butterflies) collection, 
possession, captive-rearing, and release of monarchs; scientific 
research; educational activities; possession of dead monarchs; and sale 
of captively reared monarchs.
    In this proposed rule, the range of the monarch where these 
exceptions would apply include all areas under the jurisdiction of the 
U.S. Government where the monarch occurred historically and were not 
aided by human dispersal (i.e., the contiguous United States, Puerto 
Rico, and the U.S. Virgin Islands). These exceptions would not apply to 
States that are not part of the contiguous United States (e.g., Hawaii) 
or territories that are outside the historical range of the species 
(e.g., American Samoa) because, as noted above, these activities would 
not be prohibited there.
    (1) Activities that may maintain, enhance, remove, or establish 
milkweed and nectar plants within the breeding and migratory range that 
do not result in conversion of native or naturalized grassland, 
shrubland, or forested habitats.
    These activities include the following:
    (a) Habitat restoration and management activities, such as mowing 
and haying native rangeland, that sustain monarch butterfly habitat, 
including activities to eliminate plant communities that contain 
invasive plants or noxious weeds as part of site preparations or 
habitat enhancement activities.
    (b) Livestock grazing and routine ranching activities, including 
rotational grazing, patch-burn grazing, vegetation and invasive species 
management, other grazing practices implemented to make pasture and 
rangelands productive, construction and maintenance of fences, the 
gathering and management of livestock, and the development and 
maintenance of watering facilities for livestock.
    (c) Routine agricultural activities, including plowing, drilling, 
disking, mowing, and other mechanical manipulation and management of 
lands already in use for agricultural production (e.g., conventional 
row crops, pasture, hay fields, orchards, and vineyards). This also 
includes other mechanical manipulation and land management activities 
in direct support of cultivated agriculture, such as replacement, 
upgrades, maintenance, and operation of existing infrastructure (e.g., 
buildings, irrigation conveyance structures, fences, and roads), and 
routine implementation and maintenance of agricultural conservation 
practices, such as terraces, dikes, grassed waterways, and conservation 
tillage.
    (d) Fire management actions (e.g., prescribed burns, cultural 
burns, hazardous fuel reduction activities, vegetation management, 
maintenance of fuel breaks and minimum clearance requirements, and 
other fuels reduction activities).
    (e) Silviculture practices and forest management activities that 
use State-approved best management practices.
    (f) Maintenance, enhancement, removal, and establishment of 
milkweed and nectar plants on residential and other developed 
properties.
    (g) Vegetation management activities, such as mowing, ground 
disturbance, and other management activities, that remove milkweed and/
or nectar plants when conducted at times of year when monarchs are not 
likely present.
    We intend for this proposed exception to encourage numerous small- 
and large-scale projects that will increase the quality and quantity of 
breeding habitat on the landscape in the long term. We expect localized 
removal of milkweed and nectar plants will be outweighed by an overall 
addition of these resources across the landscape, making broadscale 
public support for monarch conservation vitally important. For example, 
landscape-scale habitat restoration and management activities that 
provide for the habitat needs of monarch butterflies (e.g., mowing, 
haying native rangeland, prescribed and cultural burning, and control 
of invasive plants or noxious weeds) may remove milkweed and could 
result in take of monarchs in the short term but would also increase 
the overall quality and quantity of breeding habitat, which is likely 
to benefit monarch populations in the long term. Similarly, forest, 
fuels and wildland management activities, and rangeland management may 
have some minimal level of take of monarch butterflies but are not 
expected to rise to the level that would have a negative impact (i.e., 
would have only de minimis impacts) on the species' conservation. These 
activities can help maintain and manage native, naturalized, and 
restored grassland, shrubland, and forested habitats, which is a 
conservation benefit to the species.
    Routine agricultural activities on lands already in use for 
agricultural production, not including conversion of native or 
naturalized grassland, shrubland, and forested habitats, would result 
in loss of milkweed and nectar plants that we consider inconsequential 
to the conservation of the species. Monarchs are impacted by the 
ongoing effects of past habitat loss and degradation; therefore, 
routine agricultural activities on lands already in use for 
agricultural production will not result in significant additional 
habitat loss and degradation. This is also true for maintenance, 
enhancement, removal, or establishment of milkweed and nectar plants on 
residential and other developed properties. Vegetation management 
activities that remove milkweed and/or nectar plants when conducted at 
times of year when monarchs are not likely present and that

[[Page 100686]]

do not result in conversion of native or naturalized grassland, 
shrubland, or forested habitats would also result in a level of take 
considered inconsequential to the conservation of the species. In 
addition, some activities may provide both conservation benefits to the 
species while also contributing to an inconsequential level of take 
(e.g., livestock grazing).
    While the goal of substantially increasing the breeding habitat 
available to monarchs and reducing fragmentation of their habitat will 
require working with people in many different sectors, a high priority 
needs to be placed on working with farmers as well as the Natural 
Resources Conservation Service, Farm Service Agency, and other partners 
who work with private landowners. We will especially focus on the key 
monarch breeding and migratory areas to encourage support for voluntary 
efforts to create suitable habitat and improve connectivity of these 
habitat patches to increase the productivity of monarchs and increase 
the carrying capacity of monarch habitat on the landscape in important 
parts of the species' range.
    Under this proposed 4(d) rule, incidental take caused by activities 
that may maintain, enhance, remove, or establish milkweed and nectar 
plants within the breeding and migratory range that do not result in 
conversion of native or naturalized grassland, shrubland, or forested 
habitats will not be prohibited. These exceptions to the prohibitions 
are intended to encourage widespread adoption of voluntary milkweed and 
nectar restoration and maintenance as well as reduce the regulatory 
requirements for the public on forms of take that are considered 
inconsequential to the conservation of the species.
    (2) Implementation of comprehensive conservation plans and 
programs.
    When making a determination as to whether incidental take from 
implementation of a conservation plan or program would be excepted 
pursuant to this 4(d) rule, we would consider the following:
     Whether the plan comprehensively addresses the threats 
affecting the monarch within the plan area;
     Whether the plan establishes objective, measurable 
biological goals and objectives for population and habitat necessary to 
ensure a net conservation benefit, and provides the mechanisms by which 
those goals and objectives will be achieved;
     Whether the plan administrators demonstrate the capability 
and funding mechanisms for effectively implementing all elements of the 
plan, including enrollment of participating landowners, monitoring of 
activities, and enforcement of plan requirements, as applicable;
     Whether the plan employs an adaptive management strategy 
to ensure future program adaptation as necessary and appropriate; and
     Whether the plan includes appropriate monitoring of 
effectiveness and compliance.
    To achieve a significant increase in the availability of monarch 
breeding areas that is required for improvement in the status of the 
species, breeding habitat needs to be returned to large portions of the 
landscape where it is now nonexistent or where what remains is highly 
fragmented. Given that so much milkweed has been lost historically and 
that monarchs are impacted by the ongoing effects of this past habitat 
loss and degradation, we need an approach that encourages landowners to 
add milkweeds and nectar plants and implement actions to maintain them, 
and comprehensive plans and projects to conserve the monarch butterfly 
could be important sources of that conservation across the broader 
landscape. State-wide plans developed by or in coordination with States 
and implemented by State agents and enrolled participants (e.g., 
private landowners, local governments) are opportunities for large-
scale conservation. Likewise, programs developed by Federal agencies in 
fulfillment of their section 7(a)(1) responsibilities are also 
opportunities for large-scale conservation. Therefore, we intend for 
this proposed exception to encourage implementation of conservation 
plans and programs that comprehensively address threats affecting the 
monarch within the plan area.
    (3) Maintenance or improvement of overwintering habitat.
    Overwintering habitat is defined as habitat that provides 
overwintering monarch butterflies with the abiotic and biotic 
conditions necessary for clustering, aggregating, and feeding 
(nectaring). An overwintering site is defined as an area where 
migratory monarch butterflies cluster on trees during the fall and/or 
winter. Unlike breeding habitat, which is widely dispersed across the 
continental United States and can be quickly created in a variety of 
locations, overwintering habitat in Mexico (for the eastern migratory 
population) and California (for the western migratory population) is 
usually restricted to specific areas and consists of tree groves that 
are not easily created in new locations. Migratory monarchs require a 
very specific microclimate at overwintering sites. Maintenance and 
improvement of overwintering habitat will aid conservation and recovery 
of the species by maintaining and enhancing those specific conditions 
at existing groves. We do not regulate take in foreign countries; 
therefore, we do not prohibit incidental take resulting from 
management, including logging, of monarch overwintering habitat in 
Mexico. Our proposed 4(d) exceptions apply only to incidental take 
resulting from maintenance or improvement of monarch overwintering 
habitat in California or elsewhere in the United States. Under this 
proposed 4(d) rule, incidental take resulting from maintenance or 
improvement of monarch overwintering habitat in the United States that 
is consistent with the goals and objectives of a site-specific Service-
approved overwintering site land management plan at the site would not 
be prohibited. Our current Overwintering Site Land Management Plan 
template and an example plan are available on https://www.regulations.gov under Docket No. FWS-R3-ES-2024-0137.
    (4) Vehicle strikes.
    It is common for monarchs to be struck by vehicles and killed in 
the course of normal driving activities. Research suggests there may be 
roadkill hotspots where monarch vehicle mortality is particularly high, 
especially during periods of migration (Kantola et al. 2019, pp. 153 
and 158). The best available information shows that mortality due to 
vehicle strikes is not one of the primary drivers of changes in monarch 
populations, and it was not identified as a primary driver by monarch 
experts (Service 2024a, p. 39). At this time the impacts from monarch 
deaths due to vehicle strikes are considered minimal and not affecting 
the monarch butterfly at a population or species level. Furthermore, 
research suggests that roadside monarch habitat can still provide a net 
benefit to the species, despite losses due to collisions, through 
strategic improvements to roadside vegetation management (Kasten et al. 
2016, entire; Phillips et al. 2019, entire). Habitat along roadsides 
may provide milkweed and nectar resources in otherwise heavily 
developed and agricultural regions, as well as provide needed habitat 
connectivity across the landscape (Wu-Smart & Schacht 2019, entire; 
Ding & Eldridge 2022, entire).
    We conclude that the overall impact of vehicle strikes is not 
expected to negatively affect conservation and recovery efforts for the 
monarch butterfly. Therefore, we propose that

[[Page 100687]]

take due to vehicle strikes not be prohibited under this 4(d) rule.
    (5) Non-lethal collection, possession, captive-rearing, and release 
of a limited number of monarchs.
    Monarch butterflies are collected non-lethally, held in captivity 
(and in some cases sold), and released for a variety of purposes, 
including educational purposes. Collecting (defined in this rulemaking 
as the non-lethal capture and holding of live monarchs at any life 
stage), captively rearing (defined in this rulemaking as the holding of 
caterpillars, pupae, or adults and raising them in captivity long 
enough for them to move to the next life stage or to reproduce), and 
releasing monarchs has inspirational and educational value and can 
foster lifelong connections to nature. Collection of monarchs at any 
life stage from the wild has the potential to pose a risk to population 
numbers. After evaluating the threat of collection, we determined there 
is no evidence that the current rate of collection, in combination with 
the current rate of release, is affecting monarch populations (Service 
2024a, p. 109). However, we assume that the collection of clustering 
monarchs could have greater impacts to the populations and species' 
viability, as the migratory populations are at their smallest when 
monarchs are clustering and overwintering clusters contain concentrated 
numbers of individuals; thus, wild clustering monarchs may not be 
collected as part of this exception.
    Captive-rearing can also pose risks to wild monarch populations, 
such as through the spread of diseases and loss of genetic diversity 
(Altizer et al. 2015, p. 1), and potential negative effects to the 
fitness of individuals and their migratory capabilities (Altizer et al. 
2015, p. 2). The negative effects can greatly impact wild monarch 
populations when rearing is conducted on a large scale (Altizer et al. 
2015, pp. 1-3). However, captive-rearing on a small scale can achieve 
all the inspirational and educational benefits while reducing the risk 
of negatively affecting populations, particularly if protocols are 
followed to minimize disease and genetic impacts. For the purposes of 
this proposed rule, we describe small-scale captive-rearing as 
collection, raising, and releasing 250 or fewer monarchs in a given 
year. We consider the collection, raising, and releasing of more than 
250 monarchs per year to be a large-scale endeavor, for which a permit 
would be required through section 10(a)(1)(A) of the Act.
    We conclude that the overall impact of collecting, possessing, 
captively rearing, and releasing 250 or fewer individual monarchs at 
one location or facility (e.g., home, botanical garden, school, or 
business) is not expected to negatively affect conservation and 
recovery efforts for the monarch butterfly. Therefore, take due to 
these activities would not be prohibited under this proposed 4(d) rule. 
However, collection of clustered monarchs would be prohibited. 
Clustered monarchs are typically the individuals that will produce the 
next year's first migratory generation. The migratory populations are 
at their smallest during the overwintering time period when monarchs 
cluster (typically September through March), and it is especially 
important that these individuals survive the winter to breed in the 
spring. Therefore, our proposed exception does not include take 
resulting from handling or collection of clustered monarchs; a permit 
to do so would be required through section 10(a)(1)(A) of the Act.
    (6) Non-lethal scientific research and educational activities 
involving a limited number of monarchs.
    Future scientific research on monarch butterflies and their use in 
educational activities in the contiguous United States will aid 
conservation and recovery by leading to a better understanding and 
appreciation of the biology and ecology of the species. Activities 
associated with scientific research and education may include non-
lethal collection for purposes of handling, netting, sampling for 
disease, tagging of monarchs, and conducting life cycle and specimen 
observations of captive monarchs. The same restrictions related to 
possession and release of monarchs (i.e., limiting activities to 250 or 
fewer monarchs per year) would apply to scientific research and 
educational activities. To encourage continued and further scientific 
research and educational activities, we are proposing to include 
exceptions in the 4(d) rule that allow these activities without 
requiring additional permits; however, we do not include take of 
clustered monarchs in the exception. As discussed in the previous 
section, it is especially important that clustered overwintering 
monarchs survive the winter to breed in the spring. Therefore, we do 
not include handling or collection of clustered monarchs for scientific 
research from this exception; a permit to do so would be required 
through section 10(a)(1)(A) of the Act.
    (7) Possession of dead monarchs.
    Though overwintering monarchs can live longer, the average life 
expectancy of monarchs during the breeding season is 2 to 5 weeks. It 
is common for people to find and collect dead adult monarchs or pieces 
of wing. Collection and possession of this type is not currently a 
threat to the species. In some cases, with other species, we might be 
concerned about collection becoming a threat due to collectors 
capturing live butterflies and preserving them because the species is 
listed and likely to become more rare. However, the monarch has 
historically occurred in such large numbers and across such a large 
range that the species is already a common specimen in butterfly 
collections. The potential impacts from collection and possession of 
dead monarchs are considered minimal and not likely to affect the 
monarch butterfly at a population or species level. Collection of live 
wild adult monarchs and intentionally killing them for preservation 
purposes would be prohibited. We are proposing in this 4(d) rule that 
possession of dead monarchs collected in a lawful manner would not be 
prohibited.
    (8) Sale of captively reared monarchs.
    We propose to limit the sale of captively reared monarchs to 250 or 
fewer individuals per year from a single location or facility. It is 
common for individuals and organizations such as garden groups, 
schools, and small businesses to sell captively reared monarchs during 
the breeding season. These activities provide inspirational and 
educational value for the public but have the same risks as discussed 
above. We find that if these activities are conducted on a small scale 
(limited to 250 or fewer monarchs in a given year), the potential for 
negative impacts would be minimal.
    We conclude that the overall impact of selling 250 or fewer 
individual monarchs at one location or facility (e.g., home, botanical 
garden, school, or business) is not expected to negatively affect 
conservation and recovery efforts for the monarch butterfly. Therefore, 
take due to these activities would not be prohibited under this 
proposed 4(d) rule.

Public Comment Requested on Exception for Pesticide Use

    We seek public comment on how to address pesticide use under a 4(d) 
rule for the monarch. We recognize that certain types of pesticide use 
can have direct or indirect negative effects on monarchs, including 
aerial broadcast application of insecticides, use of herbicides that 
remove milkweeds, and use of some biopesticides. However, not all uses 
and application methods will impact monarchs. For example, insecticide 
application using hand-held sprayers, soil injection, in furrow sprays, 
tree trunk drenching, or tree injection, are unlikely to result in

[[Page 100688]]

pesticide exposure to monarchs. We seek comment on which pesticide uses 
and application methods result in exposure and adverse effects to 
monarchs, whether to except take from those uses in a 4(d) rule, and 
whether the exceptions for those uses should include measures to 
mitigate the effects of pesticides on monarchs. We also seek comment on 
whether we should tailor any measures according to the areas and times 
of the year when monarchs are present and, if so, what is the most 
feasible method to convey this information to pesticide users. Further, 
any measures should focus on minimizing impacts to monarchs by reducing 
exposure to the species, but we also seek comment on whether it is 
appropriate to offset unavoidable impacts such as through habitat 
restoration and, if so, how to accomplish this in a 4(d) rule.
    If we include mitigation measures for excepted uses and application 
methods in a 4(d) rule, we also seek comment on how to align those 
measures with the EPA's work under FIFRA to minimize the effects of 
pesticides on listed species and to ensure that FIFRA registration and 
registration review decisions comply with section 7(a)(2) (see 
Conservation Efforts and Regulatory Mechanisms, above). FIFRA, not the 
ESA, is the primary Federal law that determines the conditions under 
which pesticides may be used. Given all the EPA's ongoing work to 
address pesticide impacts on listed species (e.g., Herbicide Strategy, 
Insecticide Strategy, Vulnerable Species Action Plan), we seek to 
minimize confusion and regulatory burdens for pesticide users as a 
result of any mitigation measures we may include in a 4(d) rule for any 
excepted pesticide uses. Rather than include specific pesticide 
mitigation measures in the proposed 4(d) rule, we seek comment on how 
best to identify those measures in a manner that aligns with the EPA's 
ongoing work on this issue.
    To inform public comments, we provide additional information on 
certain pesticide uses that impact monarchs. Many insecticides are a 
threat to monarchs based on their mode of action to target insects and 
their potential exposure to monarchs. Conventional insecticides have 
active ingredients used to control insects by killing or otherwise 
preventing them from engaging in behaviors that are undesirable or 
destructive. Insecticides are used in areas where monarchs occur and 
can drift off intended use sites with certain methods of application. 
They are likely to cause lethal and sublethal effects to nontarget 
lepidopterans (i.e., the order of insects that includes butterflies and 
moths) that are exposed (Service 2024a, appendix 5). Even though 
monarchs are not typically the target of insecticides, they can be 
killed by these chemicals if they are incidentally exposed. Many 
conventional insecticides have nonspecific modes of action and are 
expected to result in mortality to most or all insect species when 
exposure exceeds a certain threshold.
    In contrast, biopesticides are typically less toxic than 
conventional pesticides and generally affect only the specific target 
insect pest and closely related organisms. Biopesticides include 
naturally occurring substances that control pests by nontoxic 
mechanisms (e.g., biochemical pesticides), microorganisms that control 
pests (e.g., microbial pesticides), and pesticidal substances produced 
by plants containing added genetic material (e.g., plant-incorporated 
protectants). While application of most biopesticides is not expected 
to affect monarchs, certain forms of the microbial pesticide Bacillus 
thuringiensis (Bt) are active against lepidopterans. Lepidoptera-active 
Bt strains produce a specific mix of insecticidal proteins that are 
active against caterpillars due to taxa-specific biological properties 
and are used to control pests such as the spongy moth. At present, 
Lepidoptera-active strains include Bacillus thuringiensis kurstaki 
(Btk) and Bacillus thuringiensis azawai (Bta), though additional 
Lepidoptera-active Bt products may be registered in the future. Other 
currently registered Bt products, such as Bacillus thuringienses 
israelensis (Bti), are not active against Lepidoptera and thus are not 
expected to cause negative effects to monarchs. Products incorporated 
with Bt, such as Bt-corn, are also not expected to cause negative 
effects to monarchs because the toxin expression in Bt-corn is limited 
to pollen, where it occurs at such low concentrations that exposure 
presents a low risk to monarchs. In addition to direct exposure to 
insecticide residues from spray application, monarchs may be exposed 
via diet to systemic insecticides that are absorbed by nectar and 
milkweed plants from the soil and become incorporated into tissues 
(e.g., leaves, flowers, pollen, and nectar). While numerous types of 
insecticides may be incorporated into plants systemically, 
neonicotinoids are a class of insecticides that is particularly known 
to distribute throughout plant tissues in this manner. Laboratory 
studies demonstrate that exposure to neonicotinoids can negatively 
affect adult, larval, and pupal survival of monarchs. However, 
concentrations of neonicotinoids in the environment from systemic 
incorporation have not been found to reach levels known to elicit the 
negative effects seen in laboratory studies.
    Another application of systemic insecticides is the direct 
application or coating of seeds with insecticides prior to planting to 
control or repel disease organisms, insects, and pests that attack 
crops or desirable plants. Because seeds are broadly treated and often 
used prophylactically (i.e., not in response to a documented pest 
outbreak), their use is widespread for certain crops. Insecticide 
applications by wet or liquid seed-coatings and slurry seed treatment 
create limited exposure pathways to the monarch. Dust-treated seed 
applications incur a potential for the dust to drift at the time of 
planting. Treated seed dust could drift off the field, exposing 
monarchs by direct contact with the insecticide or from systemic 
incorporation into nearby milkweed or nectar plants. However, the 
exposure potential to the monarch from treated seeds is orders of 
magnitude lower compared to exposure potential from aerial broadcast 
applications, and concentrations of insecticides detected in pollen and 
nectar following seed treatments are below known thresholds for 
negative effects in monarchs (Beedle and Harbin 2011, p. 8; EPA 2016, 
pp. 14-22; EPA 2020, pp. 87-88).
    Other pesticide formulation types, in contrast to liquid forms that 
can result in direct exposure, are less likely to lead to exposure of 
monarchs through contact or dietary routes and are therefore not 
expected to negatively affect monarchs. For example, solid forms of 
pesticides, such as granules or baits, are applied directly to the soil 
or turf grass typically by hand or a spreader specifically designed for 
the size of the carrier particle and provide little opportunity for 
contact with monarch adults or larvae. In addition, solid formulations 
are not expected to result in drift.
    For other pesticide classes, such as herbicides and fungicides, our 
review of the scientific information available indicates a limited 
number of individual monarchs will experience negative effects from 
direct exposure to these pesticides. We do not expect the low number of 
individuals affected from direct exposure to other classes of 
pesticides to impact the monarch butterfly at a population or species 
level. Certain herbicide uses, however, have resulted in the loss of 
milkweed and nectar, which is discussed in the Activities that may 
maintain, enhance, remove, or establish milkweed and

[[Page 100689]]

nectar plants within the breeding and migratory range that do not 
result in conversion of native or naturalized grassland, shrubland, or 
forested habitats section. As a result, we are considering what 
mitigation measures, if any, from the EPA's Herbicide Strategy (EPA 
2024a, entire) and the agency's other ESA work (EPA 2024b, entire; EPA 
2024c, entire), should inform any exceptions for herbicide use in a 
4(d) rule for the monarch. Further, the EPA is considering how habitat 
restoration and other forms of compensatory mitigation may address 
unavoidable pesticide impacts to listed species. We thus seek comment 
on whether and how we should consider habitat restoration or creation 
as an offset for unavoidable pesticide impacts to the monarch under a 
4(d) rule.

Summary

    To promote conservation of monarch butterflies in the contiguous 
United States, we need to (1) achieve a significant increase in the 
availability of milkweed and nectar plants in monarch breeding and 
migratory areas; (2) protect and enhance overwintering habitat; (3) 
avoid and minimize impacts to monarchs and their habitat from 
insecticides and herbicides; and (4) maintain public support for the 
conservation of monarch butterflies. Therefore, we focus our efforts in 
this proposed 4(d) rule on incentivizing known beneficial actions for 
the species, as well as reducing the regulatory requirements for the 
public on forms of take that are considered inconsequential to the 
conservation of the species in the contiguous United States, Puerto 
Rico, and the U.S. Virgin Islands. These exceptions would not apply to 
States or territories that are outside the historical range of the 
species because the excepted activities would not be prohibited there.
    We find that the activities resulting in take that are excepted by 
this proposed 4(d) rule will have a de minimis impact to the species 
and will promote conservation and recovery of monarch butterflies in 
the contiguous United States. The following activities are expected to 
result in low levels of take of individuals or will aid conservation 
and recovery of the species: activities that may maintain, enhance, 
remove, or establish milkweed and nectar plants within the breeding and 
migratory range; implementation of a comprehensive conservation plan 
developed by or in coordination with a State agency or implementation 
of a conservation program developed by a Federal agency; maintenance or 
improvement of monarch overwintering habitat in the United States 
consistent with a site-specific Service-approved Overwintering Site 
Land Management Plan; monarch mortality due to vehicle strikes; small-
scale (250 or fewer butterflies) collection, possession, captive-
rearing, and release of monarchs; scientific research; educational 
activities; possession of dead monarchs; and sale of captively reared 
monarchs. In order to identify how the effects of these activities on 
monarch butterflies may differ from our current understanding and what 
additional activities we should consider excepting in a 4(d) rule, we 
are requesting additional information on the exceptions in this 
proposed 4(d) rule. We specifically request public comments on how to 
address pesticide use under a 4(d) rule for the monarch. To submit 
information, see the Information Requested section.

III. Critical Habitat

Background

    Section 4(a)(3) of the Act requires that, to the maximum extent 
prudent and determinable, we designate a species' critical habitat 
concurrently with listing the species. Critical habitat is defined in 
section 3(5)(A) of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Our regulations at 50 CFR 424.02 define the geographical area 
occupied by the species as an area that may generally be delineated 
around species' occurrences, as determined by the Secretary (i.e., 
range). Such areas may include those areas used throughout all or part 
of the species' life cycle, even if not used on a regular basis (e.g., 
migratory corridors, seasonal habitats, and habitats used periodically, 
but not solely by vagrant individuals).
    Conservation, as defined under section 3(3) of the Act, means to 
use and the use of all methods and procedures that are necessary to 
bring an endangered or threatened species to the point at which the 
measures provided pursuant to the Act are no longer necessary. Such 
methods and procedures include, but are not limited to, all activities 
associated with scientific resources management such as research, 
census, law enforcement, habitat acquisition and maintenance, 
propagation, live trapping, and transplantation, and, in the 
extraordinary case where population pressures within a given ecosystem 
cannot be otherwise relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that each Federal action agency ensure, in 
consultation with the Service, that any action they authorize, fund, or 
carry out is not likely to result in the destruction or adverse 
modification of designated critical habitat. The designation of 
critical habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area. Such 
designation also does not allow the government or public to access 
private lands. Such designation does not require implementation of 
restoration, recovery, or enhancement measures by non-Federal 
landowners. Rather, designation requires that, where a landowner 
requests Federal agency funding or authorization for an action that may 
affect an area designated as critical habitat, the Federal agency 
consults with the Service under section 7(a)(2) of the Act. If the 
action may affect the listed species itself (such as for occupied 
critical habitat), the Federal agency would have already been required 
to consult with the Service even absent the designation because of the 
requirement to ensure that the action is not likely to jeopardize the 
continued existence of the species. Even if the Service were to 
conclude after consultation that the proposed activity is likely to 
result in destruction or adverse modification of the critical habitat, 
the Federal action agency and the landowner are not required to abandon 
the proposed activity, or to restore or recover the species; instead, 
they must implement ``reasonable and prudent alternatives'' to avoid 
destruction or adverse modification of critical habitat.
    Under the first prong of the Act's definition of critical habitat, 
areas within the geographical area occupied by the species at the time 
it was listed are included in a critical habitat designation if they 
contain physical or biological features (1) which are essential to the 
conservation of the species and (2) which may require special 
management considerations or protection. For these areas, critical

[[Page 100690]]

habitat designations identify, to the extent known using the best 
scientific data available, those physical or biological features that 
are essential to the conservation of the species (such as space, food, 
cover, and protected habitat).
    Under the second prong of the Act's definition of critical habitat, 
we can designate critical habitat in areas outside the geographical 
area occupied by the species at the time it is listed, upon a 
determination that such areas are essential for the conservation of the 
species.
    Section 4(b)(2) of the Act requires that we designate critical 
habitat on the basis of the best scientific data available. Further, 
our Policy on Information Standards Under the Endangered Species Act 
(published in the Federal Register on July 1, 1994 (59 FR 34271)), the 
Information Quality Act (section 515 of the Treasury and General 
Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; 
H.R. 5658)), and our associated Information Quality Guidelines provide 
criteria, establish procedures, and provide guidance to ensure that our 
decisions are based on the best scientific data available. They require 
our biologists, to the extent consistent with the Act and with the use 
of the best scientific data available, to use primary and original 
sources of information as the basis for recommendations to designate 
critical habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information from the SSA report and information developed during the 
listing process for the species. Additional information sources may 
include any generalized conservation strategy, criteria, or outline 
that may have been developed for the species; the recovery plan for the 
species; articles in peer-reviewed journals; conservation plans 
developed by States and counties; scientific status surveys and 
studies; biological assessments; other unpublished materials; or 
experts' opinions or personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not be needed 
for recovery of the species. Areas that are important to the 
conservation of the species, both inside and outside the critical 
habitat designation, will continue to be subject to: (1) Conservation 
actions implemented under section 7(a)(1) of the Act; (2) regulatory 
protections afforded by the requirement in section 7(a)(2) of the Act 
for Federal agencies to ensure their actions are not likely to 
jeopardize the continued existence of any endangered or threatened 
species; and (3) the prohibitions found in the 4(d) rule. Federally 
funded or permitted projects affecting listed species outside their 
designated critical habitat areas may still result in jeopardy findings 
in some cases. These protections and conservation tools will continue 
to contribute to recovery of the species. Similarly, critical habitat 
designations made on the basis of the best available information at the 
time of designation will not control the direction and substance of 
future recovery plans, habitat conservation plans (HCPs), or other 
species conservation planning efforts if new information available at 
the time of those planning efforts calls for a different outcome.

Physical or Biological Features Essential to the Conservation of the 
Species

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12(b), in determining which areas we will designate as 
critical habitat from within the geographical area occupied by the 
species at the time of listing, we consider the physical or biological 
features that are essential to the conservation of the species and 
which may require special management considerations or protection. The 
regulations at 50 CFR 424.02 define ``physical or biological features 
essential to the conservation of the species'' as the features that 
occur in specific areas and that are essential to support the life-
history needs of the species, including, but not limited to, water 
characteristics, soil type, geological features, sites, prey, 
vegetation, symbiotic species, or other features. A feature may be a 
single habitat characteristic or a more complex combination of habitat 
characteristics. Features may include habitat characteristics that 
support ephemeral or dynamic habitat conditions. Features may also be 
expressed in terms relating to principles of conservation biology, such 
as patch size, distribution distances, and connectivity. For example, 
physical features essential to the conservation of the species might 
include gravel of a particular size required for spawning, alkaline 
soil for seed germination, protective cover for migration, or 
susceptibility to flooding or fire that maintains necessary early-
successional habitat characteristics. Biological features might include 
prey species, forage grasses, specific kinds or ages of trees for 
roosting or nesting, symbiotic fungi, or absence of a particular level 
of nonnative species consistent with conservation needs of the listed 
species. The features may also be combinations of habitat 
characteristics and may encompass the relationship between 
characteristics or the necessary amount of a characteristic essential 
to support the life history of the species.
    In considering whether features are essential to the conservation 
of the species, we may consider an appropriate quality, quantity, and 
spatial and temporal arrangement of habitat characteristics in the 
context of the life-history needs, condition, and status of the 
species. These characteristics include, but are not limited to, space 
for individual and population growth and for normal behavior; food, 
water, air, light, minerals, or other nutritional or physiological 
requirements; cover or shelter; sites for breeding, reproduction, or 
rearing (or development) of offspring; and habitats that are protected 
from disturbance.
    Recovery of monarch butterflies will require maintaining and, where 
necessary, improving habitat across the range to ensure the long-term 
viability of the species. The physical or biological features that are 
essential to the conservation of the species and which may require 
special management considerations or protection are a subset of the 
habitat across the range necessary for species recovery. We have 
determined that the areas occupied by the monarch butterfly during the 
winter are the subset of habitat across the range needed for recovery 
that are essential to the conservation of the species (Service 2024b, 
entire). Monarchs exhibit high annual site fidelity, densely cluster at 
these sites, and are especially vulnerable to their environment (e.g., 
severe storm events, temperature fluctuations, predation, etc.) during 
the overwintering phase of their life cycle. Because we do not 
designate critical habitat outside of the United States, we are only 
designating overwintering habitat in the United States and not 
designating any areas used by migratory monarchs for overwintering in 
Mexico or elsewhere.
    We are not proposing to designate critical habitat within monarch 
butterfly breeding and migratory areas or in areas used by nonmigratory 
monarchs in the winter. Although breeding and migratory habitats are 
important and support the species' life cycle, this kind

[[Page 100691]]

of habitat in North America is broad and spatially diffuse. The 
specific geographic areas that contain essential breeding and migratory 
habitat can change in relatively short timeframes due to many reasons, 
including weather conditions, natural succession, disturbance, and 
habitat creation. The breeding habitats used by nonmigratory monarchs 
in the winter (e.g., southern Florida, Gulf Coast, southern Atlantic 
Coast, and southern Pacific Coast) have the same characteristics of 
being expansive in nature, having variability in the suitability of 
specific locations from year to year, and being used by monarchs 
opportunistically. Due to the expansive nature of the habitat (existing 
and potential), the variability in the suitability of specific 
locations from year to year, and the opportunistic nature of monarch 
habitat use, we are not proposing to designate critical habitat in 
breeding and migratory areas.
    Migratory monarchs in the western population primarily overwinter 
in groves along the coast of California and Baja California (Jepsen and 
Black 2015, p. 149). These groves are populated by a variety of tree 
species, including blue gum eucalyptus (Eucalyptus globulus), Monterey 
pine (Pinus radiata), and Monterey cypress (Hesperocyparis macrocarpa) 
(Griffiths and Villablanca 2015, pp. 41, 46-47), all of which act as 
roost trees. These groves provide indirect sunlight for the 
overwintering monarchs, sources of moisture for hydration, defense 
against freezing temperatures, and protection against strong winds 
(Tuskes and Brower 1978, p. 149; Leong 1990, pp. 908-910, Leong 1999, 
p. 213). The close proximity to the coast (average distance of 1.47 mi 
(2.37 km) also provides a mild winter climate (Leong et al. 2004, p. 
180).
    To support overwintering western monarchs, we identified a support 
zone, which is an area of overwintering habitat surrounding an 
overwintering site that provides essential resources for monarchs, such 
as nectar plants, hydration sources, and protective landscape features 
that lessen the impacts from prevailing winds on groves of trees. 
Support zones contain the nectar resources close to the overwintering 
site (within 152 m (500 ft) of the shelter zone and core zone).

Summary of Essential Physical or Biological Features

    We derive the specific physical or biological features essential to 
the conservation of the monarch butterfly from studies of the species' 
habitat, ecology, and life history as described below. Additional 
information can be found in the SSA report (Service 2024a, entire; 
available on https://www.regulations.gov under Docket No. FWS-R3-ES-
2024-0137). We have determined that the following physical or 
biological features are essential to the conservation of the monarch 
butterfly:
    1. Groves of trees (e.g., blue gum eucalyptus, Monterey pine, 
Monterey cypress, Coast redwood, coast live oak, Douglas fir, Torrey 
pine, western sycamore, bishop pine) that serve as sites for 
overwintering monarchs to cluster along the coast of California.
    2. Trees, herbaceous or shrubby vegetation, and/or topography 
surrounding overwintering groves that contribute to the following 
microclimate conditions:
    a. Indirect or dappled sunlight,
    b. Water sources (e.g., stream, pond, moist soil) for hydration,
    c. Defense against freezing temperatures, and
    d. Protection from strong winds.
    3. Supportive features nearby (i.e., within 152 m (500 ft) of) 
overwintering groves, including the following:
    a. Flowering plants for nectar,
    b. Water sources (e.g., stream, pond, moist soil) for hydration, 
and
    c. Protective landscape features (e.g., topography and vegetation 
that lessen the impacts of prevailing winds on groves of trees.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing contain features which are essential to the conservation of 
the species and which may require special management considerations or 
protection. The features essential to the conservation of the monarch 
butterfly may require special management considerations or protection 
to reduce the following threats: the ongoing impacts of loss and 
degradation of breeding, migratory, and overwintering habitat and the 
effects of climate change.
    Special management considerations or protection may be required 
within critical habitat areas to address these threats. Management 
activities that could ameliorate these threats include, but are not 
limited to, protecting overwintering habitats and maintaining the tree 
groves and the surrounding habitat; protecting and maintaining 
landscape features that contribute to the microclimate conditions of 
groves; proactively planting trees and shrubs or removing and replacing 
dead trees, where appropriate, to support long-term habitat suitability 
of overwintering sites; restoring or enhancing nectar habitat near 
overwintering areas using native, insecticide-free plants; reducing 
fuel loads and minimizing the risk of catastrophic wildfire within 
overwintering habitat through selective thinning; avoiding use of 
pesticides near overwintering sites or nectar habitat when monarchs may 
be present; and minimizing the likelihood that development projects 
will impact the quality or quantity of the habitat.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available to designate critical habitat. In accordance 
with the Act and our implementing regulations at 50 CFR 424.12(b), we 
review available information pertaining to the habitat requirements of 
the species and identify specific areas within the geographical area 
occupied by the species at the time of listing and any specific areas 
outside the geographical area occupied by the species to be considered 
for designation as critical habitat. We are not currently proposing to 
designate any areas outside the geographical area occupied by the 
species because we have not identified any unoccupied areas that meet 
the definition of critical habitat.
    Our conservation strategy and rule set for determining critical 
habitat for the monarch butterfly evaluated quantity and quality of 
areas, distribution of areas, and landscape-level considerations needed 
to conserve and maintain a sufficient number of overwintering sites 
with habitat characteristics to support high population resiliency and 
redundancy over time across the core overwintering range. We also 
attempted to capture latitudinal diversity across the core 
overwintering range. Because aggregations of many individuals can 
moderate climatic conditions experienced by overwintering monarchs and 
offer some protection, we gave priority to the largest sites (i.e., 
those having the most monarchs or largest aggregations). Overwintering 
sites that have consistently supported the largest overwintering 
aggregations through time will most likely continue to do so in the 
future. We propose to designate as critical habitat lands that we have 
determined are occupied at the time of listing (i.e., currently 
occupied) and that contain one or more of the physical or biological 
features that are essential to the conservation of the species.
    We selected sites for critical habitat based upon maximum occupancy 
rates of overwintering butterflies in California observed during the 
Western Monarch Count from 2013 to 2022 (see Xerces

[[Page 100692]]

Society 2024a, unpaginated). The criteria for selection were all 
overwintering sites that contained 1,000 or more butterflies during at 
least 3 years in the 10-year period, 5,000 or more butterflies in 1 
year of the 10-year period, or 1,000 or more butterflies during at 
least 2 years if the sites were discovered less than 10 years ago. We 
consider 1,000 monarchs to be a reasonable threshold for a site to be 
described as large; however, we require sites to meet the large-site 
threshold in 2 (if there are data limitations) or 3 years to 
demonstrate the site is suitable for overwintering (i.e., that the 
number observed was not an anomaly). Similarly, we require sites to 
meet the higher threshold of 5,000 monarchs in 1 year because 5,000 is 
sufficient to demonstrate sites are suitable for overwintering without 
needing to be repeated. We chose 10 years as the timeframe because a 
large portion of the overwintering sites were monitored during this 
period as part of the Western Monarch Count (Xerces Society 2024a, 
unpaginated) and 10 years is long enough to capture the variability of 
site use by butterflies. Additionally, the timeframe is short enough 
that we expect the majority of sites still maintain conditions that 
support large numbers of monarchs.
    For each overwintering site that met the abundance criteria, we 
identified the size and location of the site based on mapping data 
collected as part of the annual Western Monarch Count (see Xerces 
Society 2024b, unpaginated) to identify the core and shelter zones of 
each site. The core zone is the general area within an overwintering 
site that contains the trees where monarchs cluster. The shelter zone 
is the larger area where trees, other vegetation, and topography 
provide wind protection and other microclimate conditions that support 
monarch clustering and/or aggregation in the core zone. We then applied 
a 152-meter (500-foot) buffer to identify the approximate location of 
the support zone surrounding each overwintering site. The support zone 
provides essential resources for monarchs, such as nectar plants, 
hydration sources, and protective landscape features that lessen the 
impacts from prevailing winds on groves of trees. The size of the 
support zone is recommended by species experts based on observations of 
monarch movements and overwintering resources (Xerces Society and 
Service 2023, entire). Each area proposed for designation as critical 
habitat includes the core, shelter, and support zones for one or more 
overwintering sites. Together, the three zones provide all of the 
physical and biological features essential to the conservation of 
monarchs at each overwintering site, though the condition of the 
features vary by site. The areas proposed for designation as critical 
habitat meet the occupancy criteria because they hosted overwintering 
monarchs in the recent past and over a reasonable timeframe for 
observation; therefore, they are considered occupied. No unoccupied 
areas meet the definition of critical habitat because they are unlikely 
to be suitable for overwintering.
    When determining proposed critical habitat boundaries, we made 
every effort to avoid including developed areas such as lands covered 
by buildings, pavement, and other structures because, in most cases, 
such lands lack physical or biological features necessary for the 
monarch butterfly. The scale of the maps we prepared under the 
parameters for publication within the Code of Federal Regulations may 
not reflect the exclusion of such developed lands. Any such lands 
inadvertently left inside critical habitat boundaries shown on the maps 
of this proposed rule have been excluded by text in the proposed rule 
and are not proposed for designation as critical habitat. Therefore, if 
the critical habitat is finalized as proposed, a Federal action 
involving these lands would not trigger section 7 consultation with 
respect to critical habitat and the requirement of no adverse 
modification unless the specific action would affect the physical or 
biological features in the adjacent critical habitat.
    The proposed critical habitat designation is defined by the map or 
maps, as modified by any accompanying regulatory text, presented at the 
end of this document under Proposed Regulation Promulgation.

Proposed Critical Habitat Designation

    We are proposing seven units as critical habitat for the monarch 
butterfly. The critical habitat areas we describe below constitute our 
current best assessment of areas that meet the definition of critical 
habitat for the monarch butterfly. The areas we propose as critical 
habitat are within the following seven units: (1) Ventura County, (2) 
Santa Barbara County, (3) San Luis Obispo County, (4) Monterey County, 
(5) Santa Cruz County, (6) Alameda County, and (7) Marin County. Table 
2 shows the proposed critical habitat units and the approximate area of 
each unit.

     Table 2--Proposed Critical Habitat Units for Monarch Butterfly
 [All proposed units are occupied by the species. Area estimates reflect
     all land within critical habitat unit and subunit boundaries.]
------------------------------------------------------------------------
                                   Land ownership by    Size of unit in
      Critical habitat unit               type          acres (hectares)
------------------------------------------------------------------------
1. Ventura County...............  Public (Local).....            98 (39)
                                  Private............          395 (160)
2. Santa Barbara County:
    Subunit 2a..................  Public (State,                139 (56)
                                   Local).                     826 (334)
                                  Private............
    Subunit 2b..................  Public (State).....            42 (17)
                                  Private............          389 (158)
3. San Luis Obispo County:
    Subunit 3a..................  Public (State).....            86 (35)
                                  Private............          384 (155)
    Subunit 3b..................  Public (State,               365 (148)
                                   Local).                     274 (111)
                                  Private............
    Subunit 3c..................  Public (Federal,             258 (105)
                                   State, Local).               145 (59)
                                  Private............
4. Monterey County..............  Public (State,                 54 (22)
                                   Local).                      150 (61)
                                  Private............
5. Santa Cruz County............  Public (Federal,              114 (46)
                                   State, Local).               175 (71)
                                  Private............

[[Page 100693]]

 
6. Alameda County...............  Public (Local).....            54 (22)
                                  Private............           207 (84)
7. Marin County.................  Public (Federal,               53 (21)
                                   State, Local).               189 (77)
                                  Private............
                                                      ------------------
    Total.......................  ...................      4,395 (1,778)
------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding.

    We present brief descriptions of all units, and reasons why they 
meet the definition of critical habitat for the monarch butterfly, 
below. The site names and numbers listed below match those used for the 
Western Monarch Count, an annual survey conducted since the 1980s that 
is now coordinated by Mia Monroe and the Xerces Society. We use the 
same site names because that is how these locations are colloquially 
known to the public, but it is important to note that the geographic 
boundaries of the critical habitat units do not match the boundaries of 
the overwintering sites that may be found online.

Unit 1: Ventura County

    Unit 1 consists of 493 ac (199 ha) in Ventura County, California, 
and is composed of lands in city (98 ac (39 ha)) and private ownership 
(395 ac (160 ha)). It includes four areas: Arrundel Barranca (site 
#3142), Camino Real Park (site #3143), Harmon Barranca (site #3144), 
and Harbor Boulevard (site #3151). Part of the areas at Harmon Barranca 
and Camino Real Park are owned and managed by the City of Ventura. The 
monarch butterfly occupies the entire unit, and the unit contains all 
of the physical or biological features essential to the conservation of 
the species.
    Special management considerations or protection may be required 
within Unit 1 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 1. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
physical or biological features essential to the conservation of the 
species in this unit.

Unit 2: Santa Barbara County

    Unit 2 consists of two subunits in Santa Barbara County, 
California. The monarch butterfly occupies each of the subunits in this 
unit, and the subunits contain all of the physical or biological 
features essential to the conservation of the species.
    Special management considerations or protection may be required 
within Unit 2 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 2. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
physical or biological features essential to the conservation of the 
species in this unit.
    Subunit 2a consists of 964 ac (390 ha) and is composed of lands in 
city (123 ac (50 ha)), county (1 ac (less than 1 ha)), State (14 ac (6 
ha)), and private or other ownership (825 ac (334 ha)). It includes the 
following areas: Las Varas Ranch (site #2741), Ellwood/Sandpiper Golf 
Course (site #2747), Ellwood Central and West (site #2750), Ellwood 
Main (site #2751), Ellwood East (site #2752), Atascadero Creek (site 
#2765), Honda Valley (site #2772), Via Real and Padaro (site #2782), 
Lambert Road (site #2783), Carpinteria Creek (site #2799), Oil and Gas 
Buffer Zone (site #2800), Padaro Lane 2 (site #3223), and Padaro Lane 3 
(site #3224). Ellwood Mesa and the Sperling Preserve, which includes 
four areas in this subunit (Ellwood/Sandpiper Golf Course, Ellwood 
Central and West, Ellwood Main, and Ellwood East), is partially owned 
by the City of Goleta, the Land Trust for Santa Barbara County, and the 
University of California, and is managed for recreation and 
conservation. Part of the area at Atascadero Creek is within Goleta 
Beach County Park, owned by Santa Barbara County. Part of the area at 
Carpinteria Creek is within Carpinteria State Beach, owned by the State 
of California and managed by the California Department of Parks and 
Recreation. Part of the area at the Oil and Gas Buffer Zone is within 
Tar Pits Park, owned by the City of Goleta.
    Subunit 2b consists of 431 ac (174 ha) and is composed of lands in 
State (42 ac (17 ha)) and private or other ownership (389 ac (158 ha)). 
It includes the following areas: The Nature Conservancy Preserve (site 
#2723), Rancho San Augustine (site #2725), Santa Anita Creek (site 
#2728), Gaviota State Beach (site #2731), Lower Cementario (site 
#2732), and Canada Alcatraz (north) (site #2733). Gaviota State Park, 
which includes part of three areas in this subunit (Gaviota State 
Beach, Lower Cementario, and Canada Alcatraz (north)), is owned by the 
State of California and managed by the California Department of Parks 
and Recreation. Part of the area identified as The Nature Conservancy 
Preserve is within the Jack and Laura Dangermond Preserve, owned by The 
Nature Conservancy.

Unit 3: San Luis Obispo County

    Unit 3 consists of three subunits in San Luis Obispo County, 
California. The monarch butterfly occupies each of the subunits in this 
unit, and the subunits contain all of the physical or biological

[[Page 100694]]

features essential to the conservation of the species.
    Special management considerations or protection may be required 
within Unit 3 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 3. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
physical or biological features essential to the conservation of the 
species in this unit.
    Subunit 3a consists of 470 ac (190 ha) and is composed of lands in 
State (86 ac (35 ha)) and private or other ownership (384 ac (155 ha)). 
It includes the following areas: Pismo Beach (North Beach Campground) 
(site #3060), Halcyon Hill (site #3067), overwintering site in Oceano 
(site #3082), Blacklake I (site #3083), Blacklake II (site #3089), 
Woodlands Village Monarch Habitat (site #3167), and Callendar Road 
(site #3214). Pismo State Beach (which includes parts of two areas in 
this subunit: Pismo Beach (North Beach Campground) and the 
overwintering site in Oceano) and Oceana Dunes State Vehicular 
Recreation Area (which includes part of Blacklake II and Callendar Road 
areas) are owned by California Department of Parks and Recreation. The 
Sand and Surf County Park encompasses a part of the overwintering sites 
in Oceano and is owned by the County of San Luis Obispo. The Land 
Conservancy of San Luis Obispo County owns part of three areas in this 
subunit (Blacklake I and II, and Callendar Road).
    Subunit 3b consists of 639 ac (258 ha) and is composed of lands in 
city (15 ac (6 ha)), county (29 ac (12 ha)), State (321 ac (130 ha)), 
and private ownership (274 ac (111 ha)). It includes the following 
areas: Pecho Road (site #3043), Toro Creek (site #3051), Hazard Cove 
(site #3052), Monarch Lane (site #3053), Morro Bay State Park 
Campground (site #3055), Morro Bay Golf Course (site #3056), Camp Keep 
at Montana De Oro State Park (site #3058), Main and Surf Street (site 
#3076), Del Mar Park (site #3233), San Luis Obispo Creek (site #3245), 
and Cayucos Creek Road and State Highway 1 (site #3266). California 
Department of Parks and Recreation manages areas within this subunit, 
including areas within Monta[ntilde]a de Oro State Park (Hazard Cove, 
Monarch Lane, and Camp Keep) and Morro Bay State Park (Morro Bay State 
Park Campground and Morro Bay Golf Course). The County of San Luis 
Obispo owns the Toro Creek Preserve (which includes the Toro Creek 
area), the Monarch Grove Natural Area (which includes the Monarch Lane 
area), and Hardie Park (which includes the Cayucos Creek Road and State 
Highway 1 area). The City of Morro Bay owns Del Mar Park, which 
contains part of the Del Mar Park area. Part of the area at San Luis 
Obispo Creek is within the Dana Abode land, which is owned by the City 
of San Luis Obispo.
    Subunit 3c consists of 403 ac (163 ha) and is composed of lands in 
State (126 ac (51 ha)), Federal (15 ac (6 ha)), village (117 ac (47 
ha)) and private ownership (145 ac (59 ha)). It includes the following 
areas: Sebastian's Store (site #3045), Fiscalini Ranch (site #3046), 
Whitaker Flat (site #3071), Hamlet (site #3073), and overwintering site 
at Ragged Point 3 (site #3258). Hearst San Simeon State Park, which is 
owned by the California Department of Parks and Recreation, contains 
portions of both the Whitaker Flat and Hamlet areas. The Fiscalini 
Ranch area is partially owned by the village of Cambria Community 
Services District. A portion of the overwintering sites at Ragged Point 
3 is in the Los Padres National Forest, which is owned by the U.S. 
Forest Service.

Unit 4: Monterey County

    Unit 4 consists of 204 ac (83 ha) in Monterey County and is 
composed of lands in city (2 ac (1 ha)), State (52 ac (21 ha)), and 
private ownership (150 ac (61 ha)). It includes the following areas: 
overwintering site near Big Sur (site #2920), Andrew Molera State Park 
(site #2924), Pacific Grove Monarch Butterfly Sanctuary (site #2935), 
and overwintering site in Monterey (site #3192). A portion of the 
Andrew Molera State Park is owned and managed by the California 
Department of Parks and Recreation. Part of the area at the Pacific 
Grove Monarch Butterfly Sanctuary is in the baseball park, which is 
owned by the City of Pacific Grove. The monarch butterfly occupies the 
entire unit, and the unit contains all of the physical or biological 
features essential to the conservation of the species.
    Special management considerations or protection may be required 
within Unit 4 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 4. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
physical or biological features essential to the conservation of the 
species in this unit.

Unit 5: Santa Cruz County

    Unit 5 consists of 289 ac (117 ha) in Santa Cruz County and is 
composed of lands in city (3 ac (1 ha)), county (7 ac (3 ha)), State 
(87 ac (35 ha)), Federal (16 ac (7 ha)), and private ownership (175 ac 
(71 ha)). It includes the following areas: Moran Lake (site #2983), 
Natural Bridges State Beach (site #2998), Lighthouse Field (site 
#3000), and Ocean View and Marine Drive (site #3010). Part of the area 
of Moran Lake is in Moran Lake Park, which is owned by the County of 
Santa Cruz. The City of Santa Cruz owns parts of three of these areas 
in this subunit (Moran Lake, Natural Bridges State Park, and Lighthouse 
Field). A portion of both the Natural Bridges State Beach and the 
Lighthouse Field are owned and managed by the California Department of 
Parks and Recreation. Part of the Ocean View and Marine Drive area is 
contained in the California Coastal National Monument, which is owned 
by the United States Bureau of Land Management. The monarch butterfly 
occupies the entire unit, and the unit contains all of the physical or 
biological features essential to the conservation of the species.
    Special management considerations or protection may be required 
within Unit 5 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 5. Special

[[Page 100695]]

management focused on maintaining and/or enhancing the monarch 
overwintering groves, vegetation and/or topography that surround the 
groves, and habitat features nearby that support overwintering monarchs 
will benefit the physical or biological features essential to the 
conservation of the species in this unit.

Unit 6: Alameda County

    Unit 6 consists of 261 ac (105 ha) in Alameda County and is 
composed of lands in city (54 ac (22 ha)) and private ownership (207 ac 
(84 ha)). It includes the following areas: Ardenwood Historical Farm 
(site #2831), Chuck Corica Golf Course (site #2832), and San Leandro 
Golf Course (site #2833). A portion of the Ardenwood Historical Farm is 
owned by the City of Fremont. A part of the San Leandro Golf Course is 
within Marina Park, which is owned by the city of San Leandro. The 
monarch butterfly occupies the entire unit, and the unit contains all 
of the physical or biological features essential to the conservation of 
the species.
    Special management considerations or protection may be required 
within Unit 6 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 6. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
species physical or biological features essential to the conservation 
of the in this unit.

Unit 7: Marin County

    Unit 7 consists of 242 ac (98 ha) in Marin County and is composed 
of lands in county (8 ac (3 ha)), State (1 ac (less than 1 ha)), 
Federal (43 ac (18 ha)), and private ownership (189 ac (77 ha)). It 
includes the following areas: Purple Gate (site #2899), Chapman Ravine 
(site #2903), Alder Road (site #2912), Charlotte near Muir Beach (site 
#3226), and Juniper Road and Kale Road (site #3227). The United States 
National Park Service owns and manages the Point Reyes National 
Seashore (which contains a portion of the Purple Gate and Alder Road 
areas) and the Golden Gate National Recreation Area (which contains a 
portion of the Chapman Ravine and Charlotte near Muir Beach areas). A 
part of the Chapman Ravine area is contained in Stinson Beach, which is 
owned by the California Department of Fish and Wildlife. Portions of 
the Chapman Ravine area are also contained in the Upton County Beach 
and Village Green, both of which are owned by the Marin County Parks 
Department. The Marin County Parks Department also owns Agate Beach, 
which contains a portion of the Alder Road area. The monarch butterfly 
occupies the entire unit, and the unit contains all of the physical or 
biological features essential to the conservation of the species.
    Special management considerations or protection may be required 
within Unit 7 to address coastal development, unsuitable management 
practices in overwintering habitat, insecticide applications, herbicide 
applications resulting in loss of nectar sources, and impacts from 
climate change (e.g., drought, increased storm severity, extreme 
temperatures). Management activities, such as incompatible tree 
trimming or removal, nectar plant removal, and tropical milkweed 
planting, have the potential to impact the suitability of overwintering 
habitat used by monarchs in Unit 7. Special management focused on 
maintaining and/or enhancing the monarch overwintering groves, 
vegetation and/or topography that surround the groves, and habitat 
features nearby that support overwintering monarchs will benefit the 
physical or biological features essential to the conservation of the 
species in this unit.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they authorize, fund, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species. In 
addition, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action which is likely to 
jeopardize the continued existence of any species proposed to be listed 
under the Act or result in the destruction or adverse modification of 
proposed critical habitat.
    Destruction or adverse modification means a direct or indirect 
alteration that appreciably diminishes the value of critical habitat as 
a whole for the conservation of a listed species (50 CFR 402.02).
    Compliance with the requirements of section 7(a)(2) is documented 
through our issuance of:
    (1) A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    (2) A biological opinion for Federal actions that may affect, and 
are likely to adversely affect, listed species or critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species and/or 
destroy or adversely modify critical habitat, we provide reasonable and 
prudent alternatives to the project, if any are identifiable, that 
would avoid the likelihood of jeopardy and/or destruction or adverse 
modification of critical habitat. We define ``reasonable and prudent 
alternatives'' (at 50 CFR 402.02) as alternative actions identified 
during formal consultation that:
    (1) Can be implemented in a manner consistent with the intended 
purpose of the action,
    (2) Can be implemented consistent with the scope of the Federal 
agency's legal authority and jurisdiction,
    (3) Are economically and technologically feasible, and
    (4) Would, in the Service Director's opinion, avoid the likelihood 
of jeopardizing the continued existence of the listed species or avoid 
the likelihood of destroying or adversely modifying critical habitat.
    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 set forth requirements for Federal 
agencies to reinitiate consultation. Reinitiation of consultation is 
required and shall be requested by the Federal agency, where 
discretionary Federal involvement or control over the action has been 
retained or is authorized by law and: (1) If the amount or extent of 
taking specified in the incidental take statement is exceeded; (2) if 
new information reveals effects of the action that may affect listed 
species or critical habitat in a manner or to an extent not previously 
considered; (3) if the identified action is subsequently modified in a 
manner that causes an effect to the listed species or critical habitat 
that was not considered in the biological opinion or written

[[Page 100696]]

concurrence; or (4) if a new species is listed or critical habitat 
designated that may be affected by the identified action. As provided 
in 50 CFR 402.16, the requirement to reinitiate consultations for new 
species listings or critical habitat designation does not apply to 
certain agency actions (e.g., land management plans issued by the 
Bureau of Land Management in certain circumstances).

Destruction or Adverse Modification of Critical Habitat

    The key factor related to the destruction or adverse modification 
determination is whether implementation of the proposed Federal action 
directly or indirectly alters the designated critical habitat in a way 
that appreciably diminishes the value of the critical habitat for the 
conservation of the listed species. As discussed above, the role of 
critical habitat is to support physical or biological features 
essential to the conservation of a listed species and provide for the 
conservation of the species.
    Section 4(b)(8) of the Act requires that our Federal Register 
documents ``shall, to the maximum extent practicable also include a 
brief description and evaluation of those activities (whether public or 
private) which, in the opinion of the Secretary, if undertaken may 
adversely modify [critical] habitat, or may be affected by such 
designation.'' Activities that may be affected by designation of 
critical habitat for the monarch butterfly include those that may 
affect the physical or biological features of the monarch butterfly's 
critical habitat (see Physical or Biological Features Essential to the 
Conservation of the Species).

Exemptions

Application of Section 4(a)(3) of the Act

    The Sikes Act Improvement Act of 1997 (Sikes Act) (16 U.S.C. 670a) 
required each military installation that includes land and water 
suitable for the conservation and management of natural resources to 
complete an integrated natural resources management plan (INRMP) by 
November 17, 2001. An INRMP integrates implementation of the military 
mission of the installation with stewardship of the natural resources 
found on the base. Each INRMP includes:
    (1) An assessment of the ecological needs on the installation, 
including the need to provide for the conservation of listed species;
    (2) A statement of goals and priorities;
    (3) A detailed description of management actions to be implemented 
to provide for these ecological needs; and
    (4) A monitoring and adaptive management plan.
    Among other things, each INRMP must, to the extent appropriate and 
applicable, provide for fish and wildlife management; fish and wildlife 
habitat enhancement or modification; wetland protection, enhancement, 
and restoration where necessary to support fish and wildlife; and 
enforcement of applicable natural resource laws.
    The National Defense Authorization Act for Fiscal Year 2004 (Pub. 
L. 108-136) amended the Act to limit areas eligible for designation as 
critical habitat. Specifically, section 4(a)(3)(B)(i) of the Act 
provides that the Secretary shall not designate as critical habitat any 
lands or other geographical areas owned or controlled by the DoD, or 
designated for its use, that are subject to an INRMP prepared under 
section 101 of the Sikes Act, if the Secretary determines in writing 
that such plan provides a benefit to the species for which critical 
habitat is proposed for designation.
    We consult with the military on the development and implementation 
of INRMPs for installations with listed species. We analyzed INRMPs 
developed by military installations located within the range of the 
proposed critical habitat designation for the monarch butterfly to 
determine if they meet the criteria for exemption from critical habitat 
under section 4(a)(3) of the Act. The following areas are DoD lands 
with completed, Service-approved INRMPs within the proposed critical 
habitat designation.

Approved INRMPs

Vandenberg Space Force Base, Santa Barbara County, California

    Vandenberg Space Force Base (VSFB) occupies approximately 99,579 ac 
(40,298 ha) and extends along 42 mi (68 km) of the California coast in 
Santa Barbara County and varies from 5 mi (8 km) to 15 mi (24 km) in 
width. Monarch breeding and nectaring habitat is widely distributed 
throughout VSFB, and there are currently 34 known overwintering sites. 
Overwintering groves on the facility range in size from 0.13 to 556 ac 
(0.05 to 25 ha), and the dominant tree species include blue gum 
eucalyptus, Monterey pine, Monterey cypress, and coast live oak. We 
have identified 439 ac (178 ha) of overwintering habitat on the 
facility that meets the definition of critical habitat for the monarch 
butterfly.
    The INRMP for VSFB was recently updated in coordination with the 
Service (VSFB 2024, entire). The INRMP includes measures for management 
of threatened and endangered species and their habitats through a 
specific management plan called the Threatened and Endangered Species 
Management Plan (Management Plan). The Management Plan addresses all 
special-status plant and wildlife species (i.e., species that are 
federally listed species or legally protected be other regulations) 
that are known or have potential to occur at VSFB, including monarch 
butterflies, and provides resource managers a framework for 
implementing an effective, long-term management program for protection 
and conservation of special-status plants and animals and their 
habitats. The primary objective of the natural resources program on 
VSFB is to ensure continued access to land and airspace required to 
accomplish the facility's mission by maintaining these resources in a 
healthy condition. Natural resources management, in particular 
threatened and endangered species management, has been identified by 
the facility as a critical mission component because biodiversity 
conservation contributes to overall ecosystem integrity and 
sustainability, which in turn supports the facility's mission by 
maintaining natural landscapes for realistic military testing, 
training, and operations.
    The Management Plan provides a conservation benefit for the monarch 
butterfly and its breeding and overwintering habitats that occur on 
VSFB and outlines a clear, measurable path to implementation of the 
actions being taken to conserve the species and its habitats (VSFB 
2024, addendum to Tab D).
    Key threats identified in the INRMP to the monarch butterfly 
include habitat degradation, loss, or lack of active management to 
maintain grove conditions; harassment and disturbance; pest management; 
and woodcutting practices. Management actions identified and 
implemented through the INRMP for these threats include (1) conserving, 
managing, enhancing, and restoring monarch butterfly overwintering 
sites and surrounding habitat; (2) using only native, insecticide-free 
plants for habitat restoration and enhancement actions; (3) conducting 
overwintering site habitat assessments and developing and implementing 
long-term management plans; (4) avoiding the use of pesticides within 
152 m (500 ft) of overwintering sites, particularly when monarchs may 
be present; (5) not planting any type of milkweed at or adjacent to 
overwintering sites (to assist in maintaining normal migration

[[Page 100697]]

behavior); (6) monitoring monarchs and assessing conditions of 
overwintering sites during the Western Monarch Count, and monitoring 
monarch populations before and after launches that occur during the 
overwintering time period; (7) conserving known areas with milkweed 
stands from disturbance, including pesticides; (8) planting 
insecticide- and fungicide-free native milkweed and nectar plants in 
migratory and breeding areas; (9) conducting management actions within 
monarch breeding and migratory habitat outside of the time when 
monarchs are likely to be present; and (10) implementing grazing best 
management practices to avoid negative impacts on breeding monarchs.
    Based on the above considerations, and in accordance with section 
4(a)(3)(B)(i) of the Act, we have determined that the identified lands 
are subject to the VSFB INRMP and that conservation efforts identified 
in the INRMP will provide a benefit to the monarch butterfly. 
Therefore, lands within this installation are exempt from critical 
habitat designation under section 4(a)(3) of the Act. We are not 
including approximately 439 ac (178 ha) of habitat in this proposed 
critical habitat designation because of this exemption.

Consideration of Impacts Under Section 4(b)(2) of the Act

    Section 4(b)(2) of the Act states that the Secretary shall 
designate and make revisions to critical habitat on the basis of the 
best available scientific data after taking into consideration the 
economic impact, the impact on national security, and any other 
relevant impact of specifying any particular area as critical habitat. 
The Secretary may exclude any area from critical habitat if the 
benefits of exclusion outweigh those of inclusion, so long as exclusion 
will not result in extinction of the species concerned. Exclusion 
decisions are governed by the regulations at 50 CFR 424.19 and the 
Policy Regarding Implementation of Section 4(b)(2) of the Endangered 
Species Act (hereafter, the ``2016 Policy''; 81 FR 7226, February 11, 
2016), both of which were developed jointly with the National Marine 
Fisheries Service (NMFS). We also refer to a 2008 Department of the 
Interior Solicitor's opinion entitled ``The Secretary's Authority to 
Exclude Areas from a Critical Habitat Designation under Section 4(b)(2) 
of the Endangered Species Act'' (M-37016).
    In considering whether to exclude a particular area from the 
designation, we identify the benefits of including the area in the 
designation, identify the benefits of excluding the area from the 
designation, and evaluate whether the benefits of exclusion outweigh 
the benefits of inclusion. If the analysis indicates that the benefits 
of exclusion outweigh the benefits of inclusion, the Secretary may 
exercise discretion to exclude the area only if such exclusion would 
not result in the extinction of the species. In making the 
determination to exclude a particular area, the statute on its face, as 
well as the legislative history, are clear that the Secretary has broad 
discretion regarding which factor(s) to use and how much weight to give 
to any factor. In our final rules, we explain any decision to exclude 
areas, as well as decisions not to exclude, to make clear the rational 
basis for our decision. We describe below the process that we use for 
taking into consideration each category of impacts and any initial 
analyses of the relevant impacts.

Consideration of Economic Impacts

    Section 4(b)(2) of the Act and its implementing regulations require 
that we consider the economic impact that may result from a designation 
of critical habitat. To assess the probable economic impacts of a 
designation, we must first evaluate specific land uses or activities 
and projects that may occur in the area of the critical habitat. We 
then must evaluate the impacts that a specific critical habitat 
designation may have on restricting or modifying specific land uses or 
activities for the benefit of the species and its habitat within the 
areas proposed. We then identify which conservation efforts may be the 
result of the species being listed under the Act versus those 
attributed solely to the designation of critical habitat for this 
particular species. The probable economic impact of a proposed critical 
habitat designation is analyzed by comparing scenarios both ``with 
critical habitat'' and ``without critical habitat.''
    The ``without critical habitat'' scenario represents the baseline 
for the analysis, which includes the existing regulatory and socio-
economic burden imposed on landowners, managers, or other resource 
users potentially affected by the designation of critical habitat 
(e.g., under the Federal listing as well as other Federal, State, and 
local regulations). Therefore, the baseline represents the costs of all 
efforts attributable to the listing of the species under the Act (i.e., 
conservation of the species and its habitat incurred regardless of 
whether critical habitat is designated). The ``with critical habitat'' 
scenario describes the incremental impacts associated specifically with 
the designation of critical habitat for the species. The incremental 
conservation efforts and associated impacts would not be expected 
without the designation of critical habitat for the species. In other 
words, the incremental costs are those attributable solely to the 
designation of critical habitat, above and beyond the baseline costs. 
These are the costs we use when evaluating the benefits of inclusion 
and exclusion of particular areas from the final designation of 
critical habitat should we choose to conduct a discretionary 4(b)(2) 
exclusion analysis.
    Executive Order (E.O.) 14094 amends and reaffirms E.O. 12866 and 
E.O. 13563 and directs Federal agencies to assess the costs and 
benefits of available regulatory alternatives in quantitative (to the 
extent feasible) and qualitative terms. Consistent with the E.O. 
regulatory analysis requirements, our effects analysis under the Act 
may take into consideration impacts to both directly and indirectly 
affected entities, where practicable and reasonable. If sufficient data 
are available, we assess to the extent practicable the probable impacts 
to both directly and indirectly affected entities. Section 3(f) of E.O. 
12866 identifies four criteria when a regulation is considered a 
``significant regulatory action'' and requires additional analysis, 
review, and approval if met. The criterion relevant here is whether the 
designation of critical habitat may have an economic effect of $200 
million or more in any given year (section 3(f)(1) of E.O. 12866 as 
amended by E.O. 14094). Therefore, our consideration of economic 
impacts uses a screening analysis to assess whether a designation of 
critical habitat for the monarch butterfly is likely to exceed the 
threshold for a regulatory action significant under section 3(f)(1) of 
E.O. 12866, as amended by E.O. 14094.
    For this particular designation, we developed an incremental 
effects memorandum (IEM) considering the probable incremental economic 
impacts that may result from this proposed designation of critical 
habitat. The information contained in our IEM was then used to develop 
a screening analysis of the probable effects of the designation of 
critical habitat for the monarch butterfly (IEc 2024, entire). We began 
by conducting a screening analysis of the proposed designation of 
critical habitat in order to focus our analysis on the key factors that 
are likely to result in incremental economic impacts. The purpose of 
the screening analysis is to filter out particular geographical areas 
of critical habitat that are already subject to such protections and 
are, therefore, unlikely to incur incremental economic impacts. In

[[Page 100698]]

particular, the screening analysis considers baseline costs (i.e., 
absent critical habitat designation) and includes any probable 
incremental economic impacts where land and water use may already be 
subject to conservation plans, land management plans, best management 
practices, or regulations that protect the habitat area as a result of 
the Federal listing status of the species. Ultimately, the screening 
analysis allows us to focus our analysis on evaluating the specific 
areas or sectors that may incur probable incremental economic impacts 
as a result of the designation.
    The presence of the listed species in occupied areas of critical 
habitat means that any destruction or adverse modification of those 
areas is also likely to jeopardize the continued existence of the 
species. Therefore, designating occupied areas as critical habitat 
typically causes little if any incremental impacts above and beyond the 
impacts of listing the species. As a result, we generally focus the 
screening analysis on areas of unoccupied critical habitat (unoccupied 
units or unoccupied areas within occupied units). Overall, the 
screening analysis assesses whether designation of critical habitat is 
likely to result in any additional management or conservation efforts 
that may incur incremental economic impacts. This screening analysis 
combined with the information contained in our IEM constitute what we 
consider to be our economic analysis of the proposed critical habitat 
designation for the monarch butterfly; our economic analysis is 
summarized in the narrative below.
    As part of our screening analysis, we considered the types of 
economic activities that are likely to occur within the areas likely 
affected by the critical habitat designation. In our evaluation of the 
probable incremental economic impacts that may result from the proposed 
designation of critical habitat for the monarch butterfly, first we 
identified, in the IEM dated June 7, 2024, probable incremental 
economic impacts associated with the following categories of 
activities: (1) Federal lands management including coastal development, 
road and bridge maintenance, and railroad maintenance projects (Army 
Corps of Engineers, Bureau of Land Management, Department of Defense, 
Federal Highway Administration, Federal Rail Administration, National 
Park Service, U.S. Forest Service); (2) management practices in 
overwintering habitat; (3) recreation activities; (4) insecticide 
applications; (5) herbicide applications; (6) habitat restoration 
activities; (7) pipeline and utility crossing maintenance and/or 
installation (Army Corps of Engineers, Federal Energy Regulatory 
Commission); and (8) maintenance of interstate pipeline rights of way 
and electrical transmission lines (Federal Energy Regulatory 
Commission) (Service 2024c, pp. 8-9).
    We considered each industry or category individually. Additionally, 
we considered whether their activities have any Federal involvement. 
Critical habitat designation generally will not affect activities that 
do not have any Federal involvement; under the Act, designation of 
critical habitat affects only activities conducted, funded, permitted, 
or authorized by Federal agencies. If we list the species, in areas 
where the monarch butterfly is present, Federal agencies would be 
required to consult with the Service under section 7 of the Act on 
activities they authorize, fund, or carry out that may affect the 
species. If, when we list the species, we also finalize this proposed 
critical habitat designation, Federal agencies would be required to 
consider the effects of their actions on the designated habitat, and if 
the Federal action may affect critical habitat, our consultations would 
include an evaluation of measures to avoid the destruction or adverse 
modification of critical habitat.
    In our IEM, we attempted to clarify the distinction between the 
effects that would result from the species being listed and those 
attributable to the critical habitat designation (i.e., difference 
between the jeopardy and adverse modification standards) for the 
monarch butterfly's critical habitat (Service 2024c, entire). Because 
the designation of critical habitat for monarch butterfly is being 
proposed concurrently with the listing, it has been our experience that 
it is more difficult to discern which conservation efforts are 
attributable to the species being listed and those which will result 
solely from the designation of critical habitat. However, the following 
specific circumstances in this case help to inform our evaluation: (1) 
The essential physical or biological features identified for critical 
habitat are the same features essential for the life requisites of the 
species, and (2) any actions that would likely adversely affect the 
essential physical or biological features of occupied critical habitat 
are also likely to adversely affect the species itself. The IEM 
outlines our rationale concerning this limited distinction between 
baseline conservation efforts and incremental impacts of the 
designation of critical habitat for this species. This evaluation of 
the incremental effects has been used as the basis to evaluate the 
probable incremental economic impacts of this proposed designation of 
critical habitat.
    The proposed critical habitat designation for the monarch butterfly 
totals 4,395 ac (1,778 ha) in seven units, all of which are occupied by 
the species during their migratory season of fall and winter. In these 
areas, any actions that may affect the species' habitat would also 
affect designated critical habitat. We anticipate consultations for 
projects where the species is temporarily absent (e.g., during the 
summer months) but critical habitat is present to allow for movement of 
the species to be largely informal and resulting in mostly 
administrative costs and minor project adjustments to minimize impacts. 
For those formal consultations that may occur, they would most likely 
be of a magnitude that would involve both the species and critical 
habitat, and any reasonable and prudent alternatives to avoid jeopardy 
and/or adverse modification would be the same. Based on historical 
economic activity levels within the seven counties overlapping proposed 
critical habitat for the monarch butterfly, staff may be required to 
complete 27 formal consultations and 17 informal consultations per year 
on average. The cost of addressing critical habitat as part of these 
consultations may range from $42,000 to $290,000 per year, depending on 
how many consultations are triggered by critical habitat alone. While 
this additional analysis will require time and resources by both the 
Federal action agency and the Service, it is believed that, in most 
circumstances, these costs would predominantly be administrative in 
nature and would not exceed $200 million in any single year; therefore, 
they would not be significant.
    The entities most likely to incur incremental costs are parties to 
section 7 consultations, including Federal action agencies and, in some 
cases, third parties, most frequently State agencies or municipalities. 
Activities we expect would be subject to consultations that may involve 
private entities as third parties are coastal development that may 
occur on private lands. However, based on coordination efforts with 
State and local agencies, the cost to private entities within these 
sectors is expected to be relatively minor (administrative costs of 
less than $3,500 per consultation effort); therefore, they would not be 
significant (i.e., exceed $200 million in a single year).
    In conclusion, the probable incremental economic impacts of the 
monarch butterfly critical habitat designation are expected to be 
limited to additional administrative effort as well

[[Page 100699]]

as minor costs of conservation efforts resulting from future section 7 
consultations. Because all of the proposed critical habitat units are 
considered to be occupied by the species, and incremental economic 
impacts of critical habitat designation, other than administrative 
costs, are expected to be limited, few actions are anticipated to 
result in section 7 consultation for critical habitat only and 
associated project modifications. Thus, the annual administrative 
burden is unlikely to reach $200 million, which is the threshold for a 
significant regulatory action under E.O. 12866.
    We are soliciting data and comments from the public on the economic 
analysis discussed above. During the development of a final 
designation, we will consider the information presented in the economic 
analysis and any additional information on economic impacts we receive 
during the public comment period to determine whether any specific 
areas should be excluded from the final critical habitat designation 
under authority of section 4(b)(2), our implementing regulations at 50 
CFR 424.19, and the 2016 Policy. We may exclude an area from critical 
habitat if we determine that the benefits of excluding the area 
outweigh the benefits of including the area, provided the exclusion 
will not result in the extinction of this species.

Consideration of National Security Impacts

    Section 4(a)(3)(B)(i) of the Act may not cover all DoD lands or 
areas that pose potential national-security concerns (e.g., a DoD 
installation that is in the process of revising its INRMP for a newly 
listed species or a species previously not covered). If a particular 
area is not covered under section 4(a)(3)(B)(i), then national-security 
or homeland-security concerns are not a factor in the process of 
determining what areas meet the definition of ``critical habitat.'' 
However, we must still consider impacts on national security, including 
homeland security, on those lands or areas not covered by section 
4(a)(3)(B)(i) because section 4(b)(2) requires the Service to consider 
those impacts whenever it designates critical habitat. Accordingly, if 
DoD, Department of Homeland Security (DHS), or another Federal agency 
has requested exclusion based on an assertion of national-security or 
homeland-security concerns, or we have otherwise identified national-
security or homeland-security impacts from designating particular areas 
as critical habitat, we generally have reason to consider excluding 
those areas.
    However, we cannot automatically exclude requested areas. When DoD, 
DHS, or another Federal agency requests exclusion from critical habitat 
on the basis of national-security or homeland-security impacts, we must 
conduct an exclusion analysis if the Federal requester provides 
information, including a reasonably specific justification of an 
incremental impact on national security that would result from the 
designation of that specific area as critical habitat. That 
justification could include demonstration of probable impacts, such as 
impacts to ongoing border-security patrols and surveillance activities, 
or a delay in training or facility construction, as a result of 
compliance with section 7(a)(2) of the Act. If the agency requesting 
the exclusion does not provide us with a reasonably specific 
justification, we will contact the agency to recommend that it provide 
a specific justification or clarification of its concerns relative to 
the probable incremental impact that could result from the designation. 
If we conduct an exclusion analysis because the agency provides a 
reasonably specific justification or because we decide to exercise the 
discretion to conduct an exclusion analysis, we will defer to the 
expert judgment of DoD, DHS, or another Federal agency as to: (1) 
Whether activities on its lands or waters, or its activities on other 
lands or waters, have national-security or homeland-security 
implications; (2) the importance of those implications; and (3) the 
degree to which the cited implications would be adversely affected in 
the absence of an exclusion. In that circumstance, in conducting a 
discretionary section 4(b)(2) exclusion analysis, we will give great 
weight to national-security and homeland-security concerns in analyzing 
the benefits of exclusion.
    Under section 4(b)(2) of the Act, we also consider whether a 
national security or homeland security impact might exist on lands 
owned or managed by DoD or DHS. In preparing this proposal, we have 
determined that, other than the land exempted under section 
4(a)(3)(B)(i) of the Act based upon the existence of an approved INRMP 
(see Exemptions, above), the lands within the proposed designation of 
critical habitat for the monarch butterfly are not owned or managed by 
DoD or DHS. Therefore, we anticipate no impact on national security or 
homeland security.

Consideration of Other Relevant Impacts

    Under section 4(b)(2) of the Act, we consider any other relevant 
impacts, in addition to economic impacts and impacts on national 
security discussed above. To identify other relevant impacts that may 
affect the exclusion analysis, we consider a number of factors, 
including whether there are approved and permitted conservation 
agreements or plans covering the species in the area--such as safe 
harbor agreements (SHAs), CCAAs, ``conservation benefit agreements'' or 
``conservation agreements'' (CBAs) (CBAs are a new type of agreement 
replacing SHAs and CCAAs in use after April 2024 (89 FR 26070; April 
12, 2024)), or HCPs--or whether there are non-permitted conservation 
agreements and partnerships that would be encouraged by designation of, 
or exclusion from, critical habitat. In addition, we look at whether 
Tribal conservation plans or partnerships, Tribal resources, or 
government-to-government relationships of the United States with Tribal 
entities may be affected by the designation. We also consider any 
State, local, social, or other impacts that might occur because of the 
designation.

Summary of Exclusions Considered Under 4(b)(2) of the Act

    In preparing this proposal, we have determined that no HCPs or 
other management plans for the monarch butterfly currently exist that 
cover lands included in the proposed critical habitat designation, and 
the proposed designation does not include any Tribal lands or trust 
resources or any lands for which designation would have any economic or 
national security impacts. Therefore, we anticipate no impact on Tribal 
lands, partnerships, or HCPs from this proposed critical habitat 
designation and thus, as described above, we are not considering 
excluding any particular areas on the basis of the presence of 
conservation agreements or impacts to trust resources.
    However, if through the public comment period we receive 
information that we determine indicates that there are potential 
economic, national security, or other relevant impacts from designating 
particular areas as critical habitat, then as part of developing the 
final designation of critical habitat, we will evaluate that 
information and may conduct a discretionary exclusion analysis to 
determine whether to exclude those areas under authority of section 
4(b)(2) and our implementing regulations at 50 CFR 424.19. If we 
receive a request for exclusion of a particular area and after 
evaluation of supporting information we do not exclude, we will fully 
describe our decision in the final rule for this action.

[[Page 100700]]

Required Determinations

Clarity of the Rule

    We are required by E.O.s 12866 and 12988 and by the Presidential 
Memorandum of June 1, 1998, to write all rules in plain language. This 
means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help us 
revise the rule, your comments should be as specific as possible. For 
example, you should tell us the numbers of the sections or paragraphs 
that are unclearly written, which sections or sentences are too long, 
the sections where you feel lists or tables would be useful, etc.

Regulatory Planning and Review (Executive Orders 12866, 13563 and 
14094)

    Executive Order 14094 amends and reaffirms the principles of E.O. 
12866 and E.O. 13563 and states that regulatory analysis should 
facilitate agency efforts to develop regulations that serve the public 
interest, advance statutory objectives, and are consistent with E.O. 
12866 and 13563, and the Presidential Memorandum of January 20, 2021 
(Modernizing Regulatory Review). Regulatory analysis, as practicable 
and appropriate, shall recognize distributive impacts and equity, to 
the extent permitted by law. E.O. 13563 emphasizes further that 
regulations must be based on the best available science and that the 
rulemaking process must allow for public participation and an open 
exchange of ideas. We have developed this proposed rule in a manner 
consistent with these requirements.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

    Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.), 
as amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (SBREFA; title II of Pub. L. 104-121, March 29, 1996), whenever an 
agency is required to publish a notice of rulemaking for any proposed 
or final rule, it must prepare and make available for public comment a 
regulatory flexibility analysis that describes the effects of the rule 
on small entities (i.e., small businesses, small organizations, and 
small government jurisdictions). However, no regulatory flexibility 
analysis is required if the head of the agency certifies the rule will 
not have a significant economic impact on a substantial number of small 
entities. The SBREFA amended the RFA to require Federal agencies to 
provide a certification statement of the factual basis for certifying 
that the rule will not have a significant economic impact on a 
substantial number of small entities.
    According to the Small Business Administration, small entities 
include small organizations such as independent nonprofit 
organizations; small governmental jurisdictions, including school 
boards and city and town governments that serve fewer than 50,000 
residents; and small businesses (13 CFR 121.201). Small businesses 
include manufacturing and mining concerns with fewer than 500 
employees, wholesale trade entities with fewer than 100 employees, 
retail and service businesses with less than $5 million in annual 
sales, general and heavy construction businesses with less than $27.5 
million in annual business, special trade contractors doing less than 
$11.5 million in annual business, and agricultural businesses with 
annual sales less than $750,000. To determine whether potential 
economic impacts to these small entities are significant, we considered 
the types of activities that might trigger regulatory impacts under 
this designation as well as types of project modifications that may 
result. In general, the term ``significant economic impact'' is meant 
to apply to a typical small business firm's business operations.
    Under the RFA, as amended, and as understood in light of recent 
court decisions, Federal agencies are required to evaluate the 
potential incremental impacts of rulemaking on those entities directly 
regulated by the rulemaking itself; in other words, the RFA does not 
require agencies to evaluate the potential impacts to indirectly 
regulated entities. The regulatory mechanism through which critical 
habitat protections are realized is section 7 of the Act, which 
requires Federal agencies, in consultation with the Service, to ensure 
that any action authorized, funded, or carried out by the agency is not 
likely to destroy or adversely modify critical habitat. Therefore, 
under section 7, only Federal action agencies are directly subject to 
the specific regulatory requirement (avoiding destruction and adverse 
modification) imposed by critical habitat designation. Consequently, 
only Federal action agencies would be directly regulated if we adopt 
the proposed critical habitat designation. The RFA does not require 
evaluation of the potential impacts to entities not directly regulated. 
Moreover, Federal agencies are not small entities. Therefore, because 
no small entities would be directly regulated by this rulemaking, the 
Service certifies that, if made final as proposed, the proposed 
critical habitat designation will not have a significant economic 
impact on a substantial number of small entities.
    In summary, we have considered whether the proposed designation 
would result in a significant economic impact on a substantial number 
of small entities. For the above reasons and based on currently 
available information, we certify that, if made final, the proposed 
critical habitat designation would not have a significant economic 
impact on a substantial number of small business entities. Therefore, 
an initial regulatory flexibility analysis is not required.

Energy Supply, Distribution, or Use--Executive Order 13211

    Executive Order 13211 (Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use) requires 
agencies to prepare statements of energy effects ``to the extent 
permitted by law'' when undertaking actions identified as significant 
energy actions (66 FR 28355; May 22, 2001). E.O. 13211 defines a 
``significant energy action'' as an action that (i) meets the 
definition of a ``significant regulatory action'' under E.O. 12866, as 
amended by E.O. 14094; and (ii) is likely to have a significant adverse 
effect on the supply, distribution, or use of energy. In our economic 
analysis, we did not find that this proposed critical habitat 
designation would significantly affect energy supplies, distribution, 
or use. Therefore, this action is not a significant energy action, and 
no statement of energy effects is required.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), we make the following finding:
    (1) This proposed rule would not produce a Federal mandate. In 
general, a Federal mandate is a provision in legislation, statute, or 
regulation that would impose an enforceable duty upon State, local, or 
Tribal governments, or the private sector, and includes both ``Federal 
intergovernmental mandates'' and ``Federal private sector mandates.'' 
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal 
intergovernmental

[[Page 100701]]

mandate'' includes a regulation that ``would impose an enforceable duty 
upon State, local, or Tribal governments'' with two exceptions. It 
excludes ``a condition of Federal assistance.'' It also excludes ``a 
duty arising from participation in a voluntary Federal program,'' 
unless the regulation ``relates to a then-existing Federal program 
under which $500,000,000 or more is provided annually to State, local, 
and Tribal governments under entitlement authority,'' if the provision 
would ``increase the stringency of conditions of assistance'' or 
``place caps upon, or otherwise decrease, the Federal Government's 
responsibility to provide funding,'' and the State, local, or Tribal 
governments ``lack authority'' to adjust accordingly. At the time of 
enactment, these entitlement programs were: Medicaid; Aid to Families 
with Dependent Children work programs; Child Nutrition; Food Stamps; 
Social Services Block Grants; Vocational Rehabilitation State Grants; 
Foster Care, Adoption Assistance, and Independent Living; Family 
Support Welfare Services; and Child Support Enforcement. ``Federal 
private sector mandate'' includes a regulation that ``would impose an 
enforceable duty upon the private sector, except (i) a condition of 
Federal assistance or (ii) a duty arising from participation in a 
voluntary Federal program.''
    The designation of critical habitat does not impose a legally 
binding duty on non-Federal Government entities or private parties. 
Under the Act, the only regulatory effect is that Federal agencies must 
ensure that their actions are not likely to destroy or adversely modify 
critical habitat under section 7. While non-Federal entities that 
receive Federal funding, assistance, or permits, or that otherwise 
require approval or authorization from a Federal agency for an action, 
may be indirectly impacted by the designation of critical habitat, the 
legally binding duty to avoid destruction or adverse modification of 
critical habitat rests squarely on the Federal agency. Furthermore, to 
the extent that non-Federal entities are indirectly impacted because 
they receive Federal assistance or participate in a voluntary Federal 
aid program, the Unfunded Mandates Reform Act would not apply, nor 
would critical habitat shift the costs of the large entitlement 
programs listed above onto State governments.
    (2) We do not believe that this rulemaking would significantly or 
uniquely affect small governments because it is not anticipated to 
produce a Federal mandate of $100 million or more (adjusted annually 
for inflation) in any given year; that is, it is not a ``significant 
regulatory action'' under the Unfunded Mandates Reform Act. The 
designation of critical habitat imposes no obligations on State or 
local governments. By definition, Federal agencies are not considered 
small entities, although the activities they fund or permit may be 
proposed or carried out by small entities. Consequently, we do not 
believe that the proposed critical habitat designation would 
significantly or uniquely affect small government entities. Therefore, 
a small government agency plan is not required.

Takings--Executive Order 12630

    In accordance with E.O. 12630 (Government Actions and Interference 
with Constitutionally Protected Private Property Rights), we have 
analyzed the potential takings implications of designating critical 
habitat for the monarch butterfly in a takings implications assessment. 
The Act does not authorize the Services to regulate private actions on 
private lands or confiscate private property as a result of critical 
habitat designation. Designation of critical habitat does not affect 
land ownership, or establish any closures, or restrictions on use of or 
access to the designated areas. Furthermore, the designation of 
critical habitat does not affect landowner actions that do not require 
Federal funding or permits, nor does it preclude development of habitat 
conservation programs or issuance of incidental take permits to permit 
actions that do require Federal funding or permits to go forward. 
However, Federal agencies are prohibited from carrying out, funding, or 
authorizing actions that would destroy or adversely modify critical 
habitat. A takings implications assessment has been completed for the 
proposed designation of critical habitat for the monarch butterfly, and 
it concludes that, if adopted, this designation of critical habitat 
does not pose significant takings implications for lands within or 
affected by the designation.

Federalism--Executive Order 13132

    In accordance with E.O. 13132 (Federalism), this proposed rule does 
not have significant federalism effects. A federalism summary impact 
statement is not required. In keeping with Department of the Interior 
and Department of Commerce policy, we requested information from, and 
coordinated development of this proposed critical habitat designation 
with, appropriate State resource agencies. From a federalism 
perspective, the designation of critical habitat directly affects only 
the responsibilities of Federal agencies. The Act imposes no other 
duties with respect to critical habitat, either for States and local 
governments, or for anyone else. As a result, the proposed rule does 
not have substantial direct effects on the States, or on the 
relationship between the Federal Government and the States, or on the 
distribution of powers and responsibilities among the various levels of 
government. The proposed designation may have some benefit to these 
governments because the areas that contain the features essential to 
the conservation of the species are more clearly defined, and the 
physical or biological features of the habitat necessary for the 
conservation of the species are specifically identified. This 
information does not alter where and what federally sponsored 
activities may occur. However, it may assist State and local 
governments in long-range planning because they no longer have to wait 
for case-by-case section 7 consultations to occur.
    Where State and local governments require approval or authorization 
from a Federal agency for actions that may affect critical habitat, 
consultation under section 7(a)(2) of the Act would be required. While 
non-Federal entities that receive Federal funding, assistance, or 
permits, or that otherwise require approval or authorization from a 
Federal agency for an action, may be indirectly impacted by the 
designation of critical habitat, the legally binding duty to avoid 
destruction or adverse modification of critical habitat rests squarely 
on the Federal agency.

Civil Justice Reform--Executive Order 12988

    In accordance with E.O. 12988 (Civil Justice Reform), the Office of 
the Solicitor has determined that the rule would not unduly burden the 
judicial system and that it meets the requirements of sections 3(a) and 
3(b)(2) of the Order. We have proposed designating critical habitat in 
accordance with the provisions of the Act. To assist the public in 
understanding the habitat needs of the species, this proposed rule 
identifies the physical or biological features essential to the 
conservation of the species. The proposed areas of critical habitat are 
presented on maps, and the proposed rule provides several options for 
the interested public to obtain more detailed location information, if 
desired.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

    This rulemaking does not contain information collection 
requirements,

[[Page 100702]]

and a submission to the Office of Management and Budget (OMB) under the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.) is not 
required. We may not conduct or sponsor and you are not required to 
respond to a collection of information unless it displays a currently 
valid OMB control number.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    Regulations adopted pursuant to section 4(a) of the Act are exempt 
from the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et 
seq.) and do not require an environmental analysis under NEPA. We 
published a document outlining our reasons for this determination in 
the Federal Register on October 25, 1983 (48 FR 49244). This includes 
listing, delisting, and reclassification rules, as well as critical 
habitat designations and species-specific protective regulations 
promulgated concurrently with a decision to list or reclassify a 
species as threatened. The courts have upheld this position (e.g., 
Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995) (critical 
habitat); Center for Biological Diversity v. U.S. Fish and Wildlife 
Service, 2005 WL 2000928 (N.D. Cal. Aug. 19, 2005) (concurrent 4(d) 
rule)).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951, May 4, 1994), E.O. 13175 (Consultation and 
Coordination with Indian Tribal Governments), the President's 
memorandum of November 30, 2022 (Uniform Standards for Tribal 
Consultation; 87 FR 74479, December 5, 2022), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with federally recognized 
Tribes and Alaska Native Corporations (ANCs) on a government-to-
government basis. In accordance with Secretary's Order 3206 of June 5, 
1997 (American Indian Tribal Rights, Federal-Tribal Trust 
Responsibilities, and the Endangered Species Act), we readily 
acknowledge our responsibilities to work directly with Tribes in 
developing programs for healthy ecosystems, to acknowledge that Tribal 
lands are not subject to the same controls as Federal public lands, to 
remain sensitive to Indian culture, and to make information available 
to Tribes. We have determined that no Tribal lands fall within the 
boundaries of the proposed critical habitat for the monarch butterfly, 
so no Tribal lands would be affected by the proposed designation.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at https://www.regulations.gov and upon request from 
the Midwest Region Headquarters (see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this proposed rule are the staff members of 
the Fish and Wildlife Service's Species Assessment Team and the Midwest 
Region Headquarters.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Plants, 
Reporting and recordkeeping requirements, Transportation, Wildlife.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

    Authority:  16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, 
unless otherwise noted.

0
2. In Sec.  17.11, amend paragraph (h) by adding an entry for 
``Butterfly, monarch'' to the List of Endangered and Threatened 
Wildlife in alphabetical order under INSECTS to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                          Listing citations and
           Common name              Scientific name      Where listed         Status         applicable rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
             Insects
 
                                                  * * * * * * *
Butterfly, monarch..............  Danaus plexippus..  Wherever found....  T              Federal Register
                                                                                          citation when
                                                                                          published as a final
                                                                                          rule]; 50 CFR
                                                                                          17.47(k); \4d\ 50 CFR
                                                                                          17.95(i).\CH\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

0
3. Further amend Sec.  17.47, as proposed to be amended at 89 FR 63888 
(August 6, 2024) and 89 FR 79857 (October 10, 2024), by adding 
paragraph (k) to read as follows:


Sec.  17.47  Species-specific rules--insects.

* * * * *
    (k) Monarch butterfly (Danaus plexippus)--(1) Prohibitions. The 
following prohibitions that apply to endangered wildlife also apply to 
the monarch butterfly in the contiguous United States, Puerto Rico, and 
the U.S. Virgin Islands. Except as provided under paragraph (k)(2) of 
this section and Sec. Sec.  17.4 and 17.5, it is unlawful for any 
person subject to the jurisdiction of the United States to commit, to 
attempt to commit, to solicit another to commit, or cause to be 
committed, any of the following acts in regard to this species:
    (i) Import or export, as set forth at Sec.  17.21(b) for endangered 
wildlife.
    (ii) Take, as set forth at Sec.  17.21(c)(1) for endangered 
wildlife.
    (iii) Possession and other acts with unlawfully taken specimens, as 
set forth at Sec.  17.21(d)(1) for endangered wildlife.
    (iv) Interstate or foreign commerce in the course of a commercial 
activity, as set forth at Sec.  17.21(e) for endangered wildlife.
    (v) Sale or offer for sale, as set forth at Sec.  17.21(f) for 
endangered wildlife.
    (2) Exceptions from prohibitions. In regard to this species, you 
may:
    (i) Conduct activities as authorized by a permit under Sec.  17.32.
    (ii) Take, as set forth at Sec.  17.21(c)(2) through (4) for 
endangered wildlife.
    (iii) Take, as set forth at Sec.  17.31(b).
    (iv) Possess and engage in other acts with unlawfully taken 
wildlife, as set

[[Page 100703]]

forth at Sec.  17.21(d)(2) for endangered wildlife.
    (v) Take incidental to an otherwise lawful activity caused by:
    (A) Activities that may maintain, enhance, remove, or establish 
milkweed and nectar plants within the breeding and migratory range that 
do not result in conversion of native or naturalized grassland, 
shrubland, or forested habitats, which for the purposes of this 
paragraph (k) includes the contiguous United States (except 
overwintering sites), Puerto Rico, and the U.S. Virgin Islands. These 
activities include the following:
    (1) Habitat restoration and management activities, such as mowing 
and haying native rangeland, that sustain grassland, shrubland, or 
forested land with monarch butterfly habitat.
    (2) Livestock grazing and routine ranching activities, including 
rotational grazing, patch-burn grazing, vegetation and invasive species 
management, other grazing practices implemented to make pasture and 
rangelands productive, construction and maintenance of fences, the 
gathering and management of livestock, and the development and 
maintenance of watering facilities for livestock.
    (3) Routine agricultural activities, including plowing, drilling, 
disking, mowing, and other mechanical manipulation and management of 
lands already in use for agricultural production (e.g., conventional 
row crops, pasture, hay fields, orchards, and vineyards). This 
exception also includes activities in direct support of cultivated 
agriculture, such as replacement, upgrades, maintenance, and operation 
of existing infrastructure (e.g., buildings, irrigation conveyance 
structures, fences, and roads), and routine implementation and 
maintenance of agricultural conservation practices (e.g., terraces, 
dikes, grassed waterways, and conservation tillage).
    (4) Fire management actions (e.g., prescribed burns, cultural 
burns, hazardous fuel reduction activities, vegetation management, 
maintenance of fuel breaks and minimum clearance requirements, and 
other fuels reduction activities).
    (5) Silviculture practices and forest management activities that 
use State-approved best management practices.
    (6) Maintenance, enhancement, removal, and establishment of 
milkweed and nectar plants on residential and other developed 
properties.
    (7) Vegetation management activities, such as mowing, ground 
disturbance, and other management activities, that remove milkweed and/
or nectar plants when conducted at times of year when monarchs are not 
likely present.
    (B) Activities intended to conserve the species conducted by 
participants in a comprehensive conservation plan for the monarch 
butterfly developed by or in coordination with a State agency or 
agencies, or their agent(s), or implementation of a conservation 
program for the monarch butterfly developed by a Federal agency in 
fulfillment of their responsibilities under section 7(a)(1) of the Act.
    (C) Maintenance or improvement of monarch overwintering habitat in 
the United States consistent with a site-specific Service-approved 
overwintering site land management plan for the conservation of 
monarchs at the site. Overwintering habitat is defined as habitat that 
provides overwintering monarch butterflies with the abiotic and biotic 
conditions necessary for clustering, aggregating, and feeding 
(nectaring).
    (D) Vehicle strikes.
    (vi) Take caused by:
    (A) Nonlethal collection, possession, or captive-rearing of 250 or 
fewer monarchs per year at any one location or facility (such as a 
home, botanical garden, school, or business). Collection is defined as 
nonlethal capture and holding of live monarchs at any life stage. 
Captive-rearing is defined as the holding of caterpillars, pupae 
(chrysalises), or adults and raising them in captivity long enough for 
them to move to the next life stage or to reproduce. This exception 
does not apply to wild clustering monarchs.
    (B) Release of 250 or fewer captively reared or held monarch adults 
per year by any one location or facility (such as a home, botanical 
garden, school, or business).
    (C) Nonlethal scientific research and educational activities 
involving 250 or fewer monarchs per year at any one location or 
facility (such as a home, botanical garden, school, business, or 
research facility). Activities associated with scientific research and 
education may include collection for purposes of handling, netting, 
sampling for disease, tagging of monarchs, and life cycle and specimen 
observations of monarchs. This exception does not apply to wild 
clustering monarchs.
    (vii) Possess dead monarchs.
    (viii) Sell or offer for sale 250 or fewer captively reared 
monarchs per year from any one location or facility (such as a home, 
botanical garden, school, business).
0
4. Amend Sec.  17.95 in paragraph (i) by adding an entry for ``Monarch 
Butterfly (Danaus plexippus)'' after the entry for ``Island Marble 
Butterfly (Euchloe ausonides insulanus)'' to read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (i) Insects.
* * * * *
Monarch Butterfly (Danaus plexippus)
    (1) Critical habitat units are depicted for Alameda, Marin, 
Monterey, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura 
Counties, California, on the maps in this entry.
    (2) Within these areas, the physical or biological features 
essential to the conservation of monarch butterfly consist of the 
following components:
    (i) Groves of trees (e.g., blue gum eucalyptus, Monterey pine, 
Monterey cypress, Coast redwood, coast live oak, Douglas fir, Torrey 
pine, western sycamore, bishop pine) that serve as sites for 
overwintering monarchs to cluster along the coast of California.
    (ii) Trees, herbaceous or shrubby vegetation, and/or topography 
surrounding overwintering groves that contribute to the following 
microclimate conditions:
    (A) Indirect or dappled sunlight;
    (B) Water sources (e.g., stream, pond, or moist soil) for 
hydration;
    (C) Defense against freezing temperatures; and
    (D) Protection from strong winds.
    (iii) Supportive features nearby (i.e., within 152 meters (500 
feet) of) overwintering groves, including the following:
    (A) Flowering plants for nectar;
    (B) Water sources (e.g., stream, pond, or moist soil) for 
hydration; and
    (C) Protective landscape features (e.g., topography or vegetation) 
that lessen the impacts of prevailing winds on groves of trees.
    (3) Critical habitat does not include manmade structures (such as 
buildings, aqueducts, runways, roads, and other paved areas) and the 
land on which they are located existing within the legal boundaries on 
[EFFECTIVE DATE OF THE FINAL RULE].
    (4) Data layers defining map units were created using mapping data 
collected as part of the annual Western Monarch Count (see Xerces 
Society 2024b, unpaginated). Critical habitat units were then mapped 
using ``NAD 1983 California (Teale) Albers (Meters).'' The site names 
and numbers on the maps in this entry match those used for the Western 
Monarch Count annual survey. The maps in this entry, as supplemented by 
text in this entry, establish the boundaries of the critical habitat 
designation. The coordinates or plot points or both on which each map

[[Page 100704]]

is based are available to the public at https://www.regulations.gov at 
Docket No. FWS-R3-ES-2024-0137, and at the regional office responsible 
for this designation. You may obtain regional office location 
information by contacting one of the Service regional offices, the 
addresses of which are listed at 50 CFR 2.2.
    (5) Index map follows:

 Figure 1 to Monarch Butterfly (Danaus plexippus) paragraph (5)
BILLING CODE 4333-15-P
[GRAPHIC] [TIFF OMITTED] TP12DE24.002

    (6) Unit 1: Ventura County.
    (i) Unit 1 consists of 493 ac (199 ha) in Ventura County, 
California. It includes four areas: Arrundel Barranca (site #3142), 
Camino Real Park (site #3143), Harmon Barranca (site #3144), and Harbor 
Boulevard (site #3151).
    (ii) Map of Unit 1 follows:


[[Page 100705]]


Figure 2 to Monarch Butterfly (Danaus plexippus) paragraph (6)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.003

    (7) Unit 2: Santa Barbara County.
    (i) Unit 2 consists of the following two subunits in Santa Barbara 
County, California:
    (A) Subunit 2a consists of 964 ac (390 ha). It includes the 
following areas: Las Varas Ranch (site #2741), Ellwood/Sandpiper Golf 
Course (site #2747), Ellwood Central and West (site #2750), Ellwood 
Main (site #2751), Ellwood East (site #2752), Atascadero Creek (site 
#2765), Honda Valley (site #2772), Via Real and Padaro (site #2782), 
Lambert Road (site #2783), Carpinteria Creek (site #2799), Oil and Gas 
Buffer Zone (site #2800), Padaro Lane 2 (site #3223), and Padaro Lane 3 
(site #3224).
    (B) Subunit 2b consists of 431 ac (174 ha). It includes the 
following areas: The Nature Conservancy Preserve (site #2723), Rancho 
San Augustine (site #2725), Santa Anita Creek (site #2728), Gaviota 
State Beach (site #2731), Lower Cementario (site #2732), and Canada 
Alcatraz (north) (site #2733).
    (ii) Maps of Unit 2 follow:


[[Page 100706]]


Figure 3 to Monarch Butterfly (Danaus plexippus) paragraph (7)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.004


[[Page 100707]]


Figure 4 to Monarch Butterfly (Danaus plexippus) paragraph (7)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.005


[[Page 100708]]


Figure 5 to Monarch Butterfly (Danaus plexippus) paragraph (7)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.006

    (8) Unit 3: San Luis Obispo County.
    (i) Unit 3 consists of the following three subunits in San Luis 
Obispo County, California:
    (A) Subunit 3a consists of 470 ac (190 ha). It includes the 
following areas: Pismo Beach (North Beach Campground) (site #3060), 
Halcyon Hill (site #3067), overwintering site in Oceano (site #3082), 
Blacklake I (site #3083), Blacklake II (site #3089), Woodlands Village 
Monarch Habitat (site #3167), and Callendar Road (site #3214).
    (B) Subunit 3b consists of 639 ac (258 ha). It includes the 
following areas: Pecho Road (site #3043), Toro Creek (site #3051), 
Hazard Cove (site #3052), Monarch Lane (site #3053), Morro Bay State 
Park Campground (site #3055), Morro Bay Golf Course (site #3056), Camp 
Keep at Montana De Oro State Park (site #3058), Main and Surf Street 
(site #3076), Del Mar Park (site #3233), San Luis Obispo Creek (site 
#3245), and Cayucos Creek Road and State Highway 1 (site #3266).
    (C) Subunit 3c consists of 403 ac (163 ha). It includes the 
following areas: Sebastian's Store (site #3045), Fiscalini Ranch (site 
#3046), Whitaker Flat (site #3071), Hamlet (site #3073), and 
overwintering site at Ragged Point 3 (site #3258).
    (ii) Maps of Unit 3 follow:


[[Page 100709]]


Figure 6 to Monarch Butterfly (Danaus plexippus) paragraph (8)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.007


[[Page 100710]]


Figure 7 to Monarch Butterfly (Danaus plexippus) paragraph (8)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.008


[[Page 100711]]


Figure 8 to Monarch Butterfly (Danaus plexippus) paragraph (8)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.009


[[Page 100712]]


Figure 9 to Monarch Butterfly (Danaus plexippus) paragraph (8)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.010

    (9) Unit 4: Monterey County.
    (i) Unit 4 consists of 204 ac (83 ha) in Monterey County, 
California. It includes the following areas: overwintering site near 
Big Sur (site #2920), Andrew Molera State Park (site #2924), Pacific 
Grove Monarch Butterfly Sanctuary (site #2935), and overwintering site 
in Monterey (site #3192).
    (ii) Map of Unit 4 follows:


[[Page 100713]]


Figure 10 to Monarch Butterfly (Danaus plexippus) paragraph (9)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.011

    (10) Unit 5: Santa Cruz County.
    (i) Unit 5 consists of 289 ac (117 ha) in Santa Cruz County, 
California. It includes the following areas: Moran Lake (site #2983), 
Natural Bridges State Park (site #2998), Lighthouse Field (site #3000), 
and Ocean View and Marine Drive (site #3010).
    (ii) Map of Unit 5 follows:


[[Page 100714]]


Figure 11 to Monarch Butterfly (Danaus plexippus) paragraph (10)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.012

    (11) Unit 6: Alameda County.
    (i) Unit 6 consists of 261 ac (105 ha) in Alameda County, 
California. It includes the following areas: Ardenwood Historical Farm 
(site #2831), Chuck Corica Golf Course (site #2832), and San Leandro 
Golf Course (site #2833).
    (ii) Map of Unit 6 follows:


[[Page 100715]]


Figure 12 to Monarch Butterfly (Danaus plexippus) paragraph (11)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.013

    (12) Unit 7: Marin County.
    (i) Unit 7 consists of 242 ac (98 ha) in Marin County, California. 
It includes the following areas: Purple Gate (site #2899), Chapman 
Ravine (site #2903), Alder Road (site #2912), Charlotte near Muir Beach 
(site #3226), and Juniper Road and Kale Road (site #3227).
    (ii) Map of Unit 7 follows:


[[Page 100716]]


Figure 13 to Monarch Butterfly (Danaus plexippus) paragraph (12)(ii)
[GRAPHIC] [TIFF OMITTED] TP12DE24.014

* * * * *

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2024-28855 Filed 12-11-24; 8:45 am]
BILLING CODE 4333-15-C`