[Federal Register Volume 60, Number 38 (Monday, February 27, 1995)]
[Rules and Regulations]
[Pages 10694-10715]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-4531]




[[Page 10693]]

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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 Species: Southwestern Willow Flycatcher; 
Final Rule

Federal Register / Vol. 60, No. 38 / Monday, February 27, 1995 / 
Rules and Regulations 
[[Page 10694]] 

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018 AB97


Endangered and Threatened Wildlife and Plants; Final Rule 
Determining Endangered Status for the Southwestern Willow Flycatcher

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The Fish and Wildlife Service (Service) determines the 
southwestern willow flycatcher (Empidonax traillii extimus) to be an 
endangered species under the authority of the Endangered Species Act of 
1973, as amended (Act). The breeding range of this bird includes 
southern California, southern Nevada, southern Utah, Arizona, New 
Mexico, western Texas, southwestern Colorado, and extreme northwestern 
Mexico. Within this region, the species is restricted to dense riparian 
associations of willow, cottonwood, buttonbush, and other deciduous 
shrubs and trees. This habitat was historically rare and sparsely 
distributed and is currently more rare owing to extensive destruction 
and modification. The southwestern willow flycatcher is endangered by 
extensive loss of habitat, brood parasitism, and lack of adequate 
protective regulations. This rule implements Federal protection 
provided by the Act for the southwestern willow flycatcher. Designation 
of critical habitat for the southwestern willow flycatcher is deferred 
while the Service gathers further comments and reconsiders the prudence 
of designation and the appropriate boundaries of any area to be 
designated.

DATES: The listing of the southwestern willow flycatcher is effective 
March 29, 1995. Comments on the designation of critical habitat may be 
submitted until April 28, 1995.

ADDRESSES: The complete file for this rule is available for inspection, 
by appointment, during normal business hours at Ecological Services 
State Office, U.S. Fish and Wildlife Service, 2321 West Royal Palm 
Road, Suite 103, Phoenix, Arizona 85021.

FOR FURTHER INFORMATION CONTACT: Sam F. Spiller or Robert M. Marshall 
at the above address (Telephone 602/640-2720).
SUPPLEMENTARY INFORMATION:

Background

    The southwestern willow flycatcher is a small bird, approximately 
15 centimeters (cm) (5.75 inches) long. It has a grayish-green back and 
wings, whitish throat, light grey-olive breast, and pale yellowish 
belly. Two wingbars are visible; the eye ring is faint or absent. The 
upper mandible is dark, the lower is light. The song is a sneezy 
``fitz-bew'' or ``fit-za-bew,'' the call a repeated ``whitt.''
    The southwestern willow flycatcher occurs in riparian habitats 
along rivers, streams, or other wetlands, where dense growths of 
willows (Salix sp.), Baccharis, arrowweed (Pluchea sp.), buttonbush 
(Cephalanthus sp.), tamarisk (Tamarix sp.), Russian olive (Eleagnus 
sp.) or other plants are present, often with a scattered overstory of 
cottonwood (Populus sp.) (Grinnell and Miller 1944, Phillips 1948, 
Phillips et al. 1964, Whitmore 1977, Hubbard 1987, Unitt 1987, 
Whitfield 1990, Brown and Trosset 1989, Brown 1991, Sogge et al. 1993, 
Muiznieks et al. 1994). Throughout the range of E. t. extimus, these 
riparian habitats tend to be rare, widely separated, small and/or 
linear locales, separated by vast expanses of arid lands. The 
southwestern willow flycatcher has experienced extensive loss and 
modification of this habitat and is also endangered by other factors, 
including brood parasitism by the brown-headed cowbird (Molothrus ater) 
(Unitt 1987, Ehrlich et al. 1992, Sogge et al. 1993, Muiznieks et al. 
1994).
    The southwestern willow flycatcher (Order Passeriformes; Family 
Tyrannidae) is a subspecies of one of the ten North American 
flycatchers in the genus Empidonax. The willow flycatcher and alder 
flycatcher (E. alnorum) were once considered a single species, the 
Traill's flycatcher (E. traillii). Some sources [American 
Ornithologists' Union (AOU) 1983, McCabe 1991] treat E. traillii and E. 
alnorum, and all their subspecies as a superspecies, the ``traillii 
complex''. However, the two species are distinguishable by morphology 
(Aldrich 1951), song type, habitat use, structure and placement of 
nests (Aldrich 1953), eggs (Walkinshaw 1966), ecological separation 
(Barlow and McGillivray 1983), and genetic distinctness (Seutin and 
Simon 1988). The breeding range of the alder flycatcher generally 
occurs north of the willow flycatcher's range.
    The southwestern willow flycatcher is one of five subspecies of the 
willow flycatcher currently recognized (Hubbard 1987, Unitt 1987, 
Browning 1993) (Figure 1.). The breeding ranges of the widely 
distributed E. t. traillii and E. t. campestris extend across the 
northern United States and southern Canada, from New England and Nova 
Scotia west, through northern Wyoming and Montana, and into British 
Columbia. Hubbard (1987) and Unitt (1987) treated E. t. campestris as 
synonymous with E. t. traillii, but Browning (1993) considered them 
separate subspecies (Figure 1.). The subspecies E. t. adastus breeds 
from Colorado west of the plains, west through the Great Basin States 
and into the eastern portions of California, Oregon and Washington. The 
breeding range of E. t. brewsteri extends from the central California 
coast north, through western Oregon and Washington to Vancouver Island. 
The breeding range of the southwestern willow flycatcher (E. t. 
extimus) includes southern California, southern Nevada, southern Utah, 
Arizona, New Mexico, and western Texas (Hubbard 1987, Unitt 1987, 
Browning 1993). It may also breed in southwestern Colorado, but nesting 
records are lacking. Records of probable breeding E. t. extimus in 
Mexico are few and are restricted to extreme northern Baja California 
del Norte and Sonora (Unitt 1987, Wilbur 1987).
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    The willow flycatcher subspecies are distinguished primarily by 
subtle differences in color and morphology. Unitt (1987) noted that 
these differences ``* * * are minor, but differ little in magnitude 
from those distinguishing the species E. traillii from E. alnorum. In 
Empidonax, small differences in morphology may mask large differences 
in biology.''
    The subspecies E. t. extimus was described by A.R. Phillips (1948) 
from a collection by G. Monson from the lower San Pedro River in 
southeastern Arizona. The taxonomy of E. t. extimus was critically 
reviewed by Hubbard (1987), Unitt (1987), and Browning (1993). Hubbard 
(1987) gave a qualified endorsement of the validity of E. t. extimus, 
recommending continued examination of the taxonomy. Unitt (1987) found 
that E. t. extimus was distinguishable from other willow flycatchers by 
color, being paler, and morphology (primarily wing formula) but not 
overall size. Browning (1993) also found that E. t. extimus was 
distinguishable as a more pale-colored subspecies. The song dialect of 
E. t. extimus may also be distinguishable from other willow 
flycatchers. Rather than the crisp, sneezy ``fitz-bew'' of the 
northerly subspecies, E. t. extimus sings a more protracted, slurred 
``fit-za-bew,'' with a burry ``bew'' syllable (recordings by M. Sogge 
and J. Travis). The subspecies E. t. extimus is accepted by most 
authors (e.g., Aldrich 1951, Behle and Higgins 1959, Phillips et al. 
1964, Bailey and Niedrach 1965, Oberholser 1974, Monson and Phillips 
1981, Harris et al. 1987, Schlorff 1990, Harris 1991). Section 3(15) of 
the Act and regulations at 50 CFR 424.02(k) defines the term 
``species'' as any subspecies of fish or wildlife or plants, and any 
distinct population segment of any vertebrate species which interbreeds 
when mature. Based on the above information, the Service has determined 
that E. t. extimus is eligible for protection under the Act.
    The southwestern willow flycatcher nests in thickets of trees and 
shrubs approximately 4-7 meters (m) (13-23 feet) or more in height, 
with dense foliage from approximately 0-4 m (13 feet) above ground, and 
often a high canopy cover percentage. The diversity of nest site plant 
species may be low (e.g., willows) or comparatively high (e.g., 
mixtures of willow, buttonbush, cottonwood, boxelder, Russian olive, 
Baccharis, and tamarisk). Nest site vegetation may be even- or uneven-
aged, but is usually dense and structurally homogeneous (Brown 1988, 
Whitfield 1990, Sogge et al. 1993, Muiznieks et al. 1994). 
Historically, E. t. extimus nested primarily in willows, buttonbush, 
and Baccharis, with a scattered overstory of cottonwood (Grinnell and 
Miller 1944, Phillips 1948, Whitmore 1977, Unitt 1987). Following 
modern changes in riparian plant communities, E. t. extimus still nests 
in native vegetation where available, but has been known to nest in 
thickets dominated by tamarisk and Russian olive (Hubbard 1987, Brown 
1988, Sogge et al. 1993, Muiznieks et al. 1994). Sedgwick and Knopf 
(1992) found that sites selected as song perches by male willow 
flycatchers (E. t. traillii/campestris) exhibited higher variability in 
shrub size than did nest sites and often included large central shrubs. 
Habitats not selected for either nesting or singing were narrower 
riparian zones, with greater distances between willow patches and 
individual willow plants. Nesting willow flycatchers of all subspecies 
generally prefer areas with surface water nearby (Bent 1960, Stafford 
and Valentine 1985, Harris et al. 1987), but E. t. extimus virtually 
always nests near surface water or saturated soil (Phillips et al. 
1964, Muiznieks et al. 1994). At some nest sites surface water may be 
present early in the breeding season but only damp soil is present by 
late June or early July (Muiznieks et al. 1994, M. Whitfield, Kern 
River Research Center, in litt.-1993, J. and J. Griffith, Griffith 
Wildlife Biology, in litt.-1993). Ultimately, a water table close 
enough to the surface to support riparian vegetation is necessary.
    Defining a minimum habitat patch size required to support a nesting 
pair of E. t. extimus is difficult. Throughout its range, determining 
the capability of habitat patches to support southwestern willow 
flycatchers is confused by the species' rarity, unstable populations, 
variations in habitat types, and other factors. However, the available 
information indicates that habitat patches as small as 0.5 hectare (ha) 
(1.23 acres) can support one or two nesting pairs. Sogge et al. (1993) 
found territorial flycatchers in habitat patches ranging from 0.5 to 
1.2 ha (1.23 to 2.96 acres). Two habitat patches of 0.5 and 0.9 ha 
(1.23 and 2.2 acres) each supported two territories. Muiznieks et al. 
(1994) also reported groups of territorial E. t. extimus in habitat 
patches of approximately one to several hectares.
    The nest is a compact cup of fiber, bark, and grass, typically with 
feathers on the rim, lined with a layer of grass or other fine, silky 
plant material, and often has plant material dangling from the bottom 
(Harrison 1979). It is constructed in a fork or on a horizontal branch, 
approximately 1-4.5 m (3.2-15 feet) above ground in a medium-sized bush 
or small tree, with dense vegetation above and around the nest (Brown 
1988, Whitfield 1990, Muiznieks et al. 1994).
    The southwestern willow flycatcher is present and singing on 
breeding territories by mid-May, although its presence and status is 
often confused by the migrating individuals of northern subspecies 
passing through E. t. extimus breeding habitat [D. Kreuper, Bureau of 
Land Management (BLM), unpubl. data]. The southwestern willow 
flycatcher builds nests and lays eggs in late May and early June and 
fledges young in early to mid-July (Willard 1912, Ligon 1961, Brown 
1988, Whitfield 1990, Sogge and Tibbitts 1992, Sogge et al. 1993, 
Muiznieks et al. 1994). Some variation in these dates has been observed 
(Carothers and Johnson 1975, Brown 1988, Muiznieks et al. 1994) and may 
be related to altitude, latitude, and renesting.
    The southwestern willow flycatcher is an insectivore. It forages 
within and above dense riparian vegetation, taking insects on the wing 
or gleaning them from foliage (Wheelock 1912, Bent 1960). It also 
forages in areas adjacent to nest sites, which may be more open (M. 
Sogge, National Biological Survey, pers. comm. 1993). No information is 
available on specific prey species.
    The migration routes and wintering grounds of E. t. extimus are not 
well known. Empidonax flycatchers rarely sing during fall migration, so 
that a means of distinguishing subspecies is not available (Blake 1953, 
Peterson and Chalif 1973). However, willow flycatchers have been 
reported to sing and defend winter territories in Mexico and Central 
America (Gorski 1969, McCabe 1991). The southwestern willow flycatcher 
most likely winters in Mexico, Central America, and perhaps northern 
South America (Phillips 1948, Peterson 1990). However, the habitats it 
uses on wintering grounds are unknown. Tropical deforestation may 
restrict wintering habitat for this and other neotropical migratory 
birds (Finch 1991, Sherry and Holmes 1993).
    Breeding bird survey data for 1965 through 1979 combined the willow 
and alder flycatchers into a ``Traill's flycatcher superspecies'', 
because of taxonomic uncertainty during the 15-year reporting period. 
These data showed fairly stable numbers in central and eastern North 
America but strong declines in the West, the region including the range 
of the southwestern willow flycatcher, and where the alder flycatcher 
is absent (Robbins et al. 1986). [[Page 10697]] 
    Unitt (1987) reviewed historical and contemporary records of E. t. 
extimus throughout its range, determining that it had ``declined 
precipitously,'' and that ``although the data reveal no trend in the 
past few years, the population is clearly much smaller now than 50 
years ago, and no change in the factors responsible for the decline 
seem likely.'' Data are now available that indicate continued declines, 
poor reproductive performance, and/or continued threats for most 
remaining populations (Brown 1991, Whitfield and Laymon, Kern River 
Research Center, in litt. 1993, Sogge and Tibbitts 1992, Sogge et al. 
1993, Muiznieks et al. 1994).

Previous Federal Actions

    The Service included the southwestern willow flycatcher on its 
Animal Notice of Review as a category 2 candidate species on January 6, 
1989 (54 FR 554). A category 2 species is one for which listing may be 
appropriate but for which additional biological information is needed. 
After soliciting and reviewing additional information, the Service 
elevated E. t. extimus to category 1 candidate status on November 21, 
1991 (56 FR 58804). A category 1 species is one for which the Service 
has on file substantial information to support listing, but for which a 
proposal to list has not been issued because it is precluded at present 
by other listing activity.
    On January 25, 1992, a coalition of conservation organizations 
(Suckling et al. 1992) petitioned the Service, requesting listing of E. 
t. extimus as an endangered species under the Act. The petitioners also 
requested emergency listing and designation of critical habitat. On 
September 1, 1992, the Service published a finding (57 FR 39664) that 
the petition presented substantial information indicating that listing 
may be warranted and requested public comments and biological data on 
the species. On July 23, 1993, the Service published a proposal (58 FR 
39495) to list E. t. extimus as endangered with critical habitat, and 
again requested public comments and biological data on the southwestern 
willow flycatcher.

Summary of Comments and Recommendations
    In the July 23, 1993, proposed rule (58 FR 39495) and associated 
notifications, all interested parties were requested to submit comments 
or information that might bear on whether to list the southwestern 
willow flycatcher. The comment period was originally scheduled to close 
October 21, 1993, then was extended to November 30, 1993. Appropriate 
State agencies, county governments, Federal agencies, scientific 
organizations, and other interested parties were contacted and 
requested to comment. Newspaper notices inviting public comment were 
published in the following newspapers; In California, Los Angeles 
Times, L.A. Watts Times, Kern Valley Sun, and San Diego Union-Tribune; 
in Arizona, Arizona Daily Sun, Arizona Republic, Tucson Daily Citizen, 
White Mountain Independent, and Arizona Daily Star; in New Mexico, 
Albuquerque Journal, Albuquerque Tribune, Santa Fe New Mexican, 
Carlsbad Current-Argus, Silver City Daily Press; in Nevada, Las Vegas 
Sun; in Colorado, Durango Herald; in Utah, Daily Spectrum; and in 
Texas, El Paso Times. The inclusive dates of publications were August 
31 through September 13, 1993, for the initial comment period and 
October 28 through November 5, 1993, for the public hearings and 
extension of public comment period.
    The Service held six public hearings. Because of anticipated 
interest in the proposed rule, the Service announced its intention to 
hold at least three public hearings. In response to requests from the 
public, three additional hearings were scheduled. A notice of the 
hearing dates and locations was published in the Federal Register on 
October 18, 1993 (58 FR 53702). Approximately 424 people attended the 
hearings. About 17 people attended the hearing in Tucson, Arizona; 27 
in Flagstaff, Arizona; 10 in Las Cruces, New Mexico; 12 in Albuquerque, 
New Mexico; 350 in Lake Isabella, California; and 8 in San Diego, 
California. Transcripts of these hearings are available for inspection 
(see ADDRESSES).
    A total of 3,102 written comment letters were received at the 
Service's Ecological Services State Office in Arizona: 264 supported 
the proposed listing; 2,650 opposed the proposed listing; and 188 
expressed neither support nor opposition, but either commented on 
information in the proposed rule, provided additional information, or 
were non-substantive or irrelevant to the proposed listing.
    Oral or written comments were received from 62 parties at the 
hearings: 8 supported the proposed listing; 40 opposed the proposed 
listing; and 14 expressed neither support nor opposition but provided 
additional information, or were non-substantive or irrelevant to the 
proposed listing.
    In total, oral or written comments were received from 31 Federal 
and State agencies and officials, 17 local officials, and 3,116 private 
organizations, companies, and individuals. All comments received during 
the comment period are addressed in the following summary. Comments of 
a similar nature are grouped into a number of general issues.
    Issue 1: The American Ornithologists' Union (AOU) did not list E. 
t. extimus in its latest Checklist of North American Birds; Unitt 
(1987) could not distinguish E. t. extimus by color or morphology; 
genetic analysis is necessary to distinguish subspecies; significant 
disagreement exists among scientists regarding taxonomy, for example, 
McCabe (1991) did not recognize E. t. extimus; the willow flycatcher 
subspecies, in fact the North American Empidonax flycatcher species are 
too difficult to distinguish to make it reasonable to list subspecies 
of those species; hybridization of the willow flycatcher subspecies 
occurs; subspecies are not worth listing; E. t. extimus is a subspecies 
of a very common species; E. t. extimus is not worth listing because it 
is one of nine common species in the genus Empidonax; this subspecies 
and subspecies in general are of minor ecological value; their loss 
would be unimportant; there is little value in preserving rare species/
subspecies; and historical taxonomic questions may confuse population 
trend information.
    Service Response: The Service has determined that E. t. extimus is 
a valid taxon. The Service relies on the most current and authoritative 
data available in making decisions regarding the validity of species, 
subspecies, or distinct vertebrate population segments. These data 
include articles published in professional journals, agency reports, 
and other unpublished data provided by researchers. For the 
southwestern willow flycatcher, the Service reviewed this information 
and found a majority opinion that E. t. extimus is a valid subspecies. 
Authorities who critically examined the taxonomy of E. traillii and 
recognized E. t. extimus include Phillips (1948), Aldrich (1951), 
Hubbard (1987), Unitt (1987), and Browning (1993). Other authorities 
accepting the subspecies include Behle and Higgins (1959), Phillips et 
al. (1964), Bailey and Niedrach (1965), Oberholser (1974), Monson and 
Phillips (1981), Harris et al. (1987), Schlorff (1990), Whitfield 
(1990), Brown (1991), Harris (1991), Western Foundation for Vertebrate 
Zoology in litt. 1993, University of California in litt. 1993. The AOU 
(1983) did not list subspecies of any bird, including the willow 
flycatcher, in its 1983 Checklist of North America Birds. However, this 
does not indicate a lack of recognition of E. t. extimus, or for the 
concept of subspecies. The preface to the 1983 Checklist states ``The 
Committee [[Page 10698]] strongly endorses the concept of the 
subspecies * * * and we wish to make it clear that the omission of 
separate listings of subspecies in this edition is not a rejection of 
the validity or utility of this systematic category * * *.''
    The Service noted McCabe's (1991) consideration of the willow and 
alder (E. alnorum) flycatchers as a single species, and his reluctance 
to recognize willow flycatcher subspecies. McCabe (1991) provides a 
thorough review of the history of E. alnorum and E. traillii taxonomy, 
and the questions of ecological, morphological, and song-type 
distinction on which this taxonomic evaluation has been based. However, 
the Service agrees with Sedgwick's (1993) comments and McCabe's own 
observation that McCabe (1991) contrasts with the majority opinion 
regarding taxonomy of the willow and alder flycatchers.
    After examining 305 study skins, Unitt (1987) found that while four 
subspecies (E. t. traillii, E. t. adastus, E. t. brewsteri, and E. t. 
extimus) could be tentatively separated by the ``75 percent rule'' 
using overall size (wing and tail lengths and their ratios to one 
another), these criteria were not satisfactorily conclusive. However, 
he found that the subspecies could be satisfactorily distinguished, 
under the ``75 percent rule,'' using color, wing formula (relative 
lengths of primary wing feathers), or both. Browning (1993) examined 
270 specimens and found that all four subspecies, and a fifth (E. t. 
campestris) were distinguishable by color.
    The Service acknowledges that taxonomy of E. traillii races 
continues to pose questions and may be revised in the future. The 
Service has determined that E. t. extimus is a sufficiently distinct 
entity to be listed under the Act at the very least as a distinct 
vertebrate population [50 CFR Sec. 424.02(k)]. However, the Service 
accepts the majority opinion that E. t. extimus is a valid subspecies 
and lists it as such.
    The Service considers taxonomic distinctness in assigning 
priorities for species listings, but not in determining whether or not 
to list species. The Act authorizes listing of species, subspecies, or 
distinct population segments, all of which have ecological 
significance.
    Issue 2: The southwestern willow flycatcher is not a riparian 
obligate species. It also occurs in open prairie woodlots, dry and 
brushy pastures, and brushy fields or slopes. No surveys of dry 
habitats have been done to prove riparian obligacy. The southwestern 
willow flycatcher does not ``invariably'' nest near surface water.
    Service Response: The Service is unaware of any study, report, or 
species account that describes E. t. extimus as anything but a riparian 
obligate. No commenter provided data, studies, or reports indicating 
that E. t. extimus nests outside riparian habitats. Several commenters 
cited field guides which describe the willow flycatcher (all 
subspecies) as occurring ``* * * in drier situations (than the alder 
flycatcher) * * *'' (Peterson 1990), ``* * * on brushy slopes * * *'' 
(Robbins et al. 1983), and ``* * * dry, brushy upland pastures * * *'' 
(National Geographic Society 1990). The Service believes that field 
guide species accounts do not constitute the best available scientific 
information on biology, ecology or habitat requirements. Field guide 
accounts tend to be brief and generalized, and in this case represent 
habitat use of other willow flycatcher subspecies, which occur in more 
mesic regions. Similarly, Barlow and McGillivray's (1983) description 
of willow flycatchers (E. t. campestris/traillii) selecting ``* * * a 
more xeric upland habitat * * *'' in Ontario, Canada, is not considered 
relevant to habitat selection of E. t. extimus in the desert Southwest. 
In the wetter climates of the north, upper midwest, and northeast, 
habitat conditions of moist soil or surface water, supporting thickets 
of deciduous shrubs and trees, are not restricted to riparian areas. 
However, in the arid Southwest where E. t. extimus occurs, these 
conditions are limited to riparian areas, usually in profound contrast 
to the adjacent and prevailing desert conditions. Various authors 
(e.g., King 1955) have noted that while willow flycatchers may nest 
away from riparian areas in the north and east, in arid regions (the 
ranges of E. t. brewsteri and E. t. extimus particularly) the species 
is restricted to riparian habitats. Regarding the presence of surface 
water during the breeding season, new information was provided 
indicating that some nest sites have surface water in close proximity 
early in the breeding season, which recedes underground by the end of 
the breeding season. At these sites, the water table remains at least 
high enough to sustain riparian vegetation. The Service is unaware of 
any surveys performed in non-riparian habitats specifically to verify 
the absence of nesting E. t. extimus. However, the Service relied on 
local, State, and regional species accounts of distribution and habitat 
use, none of which describe occurrence outside of riparian habitats.
    Issue 3: The loss and modification of southwestern riparian habitat 
is overstated, poorly documented, and does not constitute a threat to 
the flycatcher; the statement that 90 percent loss of riparian habitat 
has occurred is inaccurate and an exaggeration; riparian habitat has 
not decreased, but increased as a result of diversions, irrigation, 
etc; habitat has increased, not decreased, in local area(s) over the 
past 20 years; riparian regeneration is approaching 1,000 percent in 
southeastern Arizona; Hastings and Turner (1965) show that cottonwood 
riparian habitat has increased in southeastern Arizona; the upper San 
Pedro River is recovered, not ``unsuitable and unoccupied'' as the 
Service claimed; because tamarisk has increased, and E. t. extimus uses 
tamarisk, tamarisk invasion does not constitute modification of 
habitat, but expansion of habitat; population declines in the past 20 
years are concurrent with improved riparian habitats, so no correlation 
exists between trends in habitat and populations; the proposal fails to 
support claims that urban development, agriculture, and livestock 
grazing are harmful to the flycatcher.
    Service Response: The Service has determined that the documentation 
of loss and modification of southwestern riparian habitats, cited in 
this final rule, is adequate. Regarding the ``90 percent loss and 
modification'' statement, the proposed rule stated that ``* * * as much 
as 90 percent * * *'' (emphasis added) has been lost or modified. The 
actual percentage lost or modified is not expected to be consistent 
across the region, but should vary with elevation, rainfall, geographic 
area, relative size of drainage system, and severity of impacts. Loss 
and modification may be lesser at higher elevations, where 
precipitation is greater and evaporation less. In most major lower 
elevation desert riparian systems, loss or modification may in fact be 
near 100 percent, e.g., the lower Colorado, lower Gila, lower Rio 
Grande, and lower Salt Rivers. Because ``modification'' includes 
alterations in flow regimes, channel confinement, changes in water 
quality, and floristic makeup of riparian systems, the Service believes 
it is not a misrepresentation to state that up to 90 percent of 
southwestern riparian ecosystems have been lost or modified.
    Commenters stating that riparian habitat has not decreased, but 
increased as a result of diversions and irrigation, presented no 
supporting information. The Service recognizes that some diversions, 
particularly unmaintained irrigation ditches, sometimes support 
riparian vegetation. However, the Service believes diversion and 
irrigation result in a net loss of riparian habitat. 
[[Page 10699]] Where riparian vegetation becomes established along 
irrigation systems, it is often cleared away at regular intervals. 
Where it is not, it is sometimes because an artificially created 
riparian/wetland habitat is being maintained as mitigation or 
compensation for loss of natural riparian habitat elsewhere.
    The Service recognizes that in some local areas in recent decades, 
riparian habitat has been rehabilitated or increased, not decreased. 
However, the Service accepts the consensus of literature cited in this 
rule that the overall trend continues to be one of habitat loss.
    Hastings and Turner (1965) and Bahre (1991) noted that riparian 
habitats were already significantly altered by the turn of the last 
century. Hastings and Turner (1965) also noted that all major 
watercourses in southern Arizona suffered entrenchment and became more 
ephemeral in flow in approximately 1890. Land use practices that had 
already affected riparian habitats in this Arizona-Mexico border region 
included livestock grazing, woodcutting, and water diversion; climatic 
changes may also have contributed. The differences between the historic 
and more recent photographs show some riparian recovery, concurrent 
with reductions in livestock stocking levels from their highs in the 
late 1800's. No data, or elaboration, were presented to support 
statements that riparian regeneration is approaching 1000 percent in 
southeastern Arizona.
    As this final rules discusses, E. t. extimus sometimes nests in 
tamarisk, but does so at lower densities, and apparently at lower 
success rates than in native vegetation (Hunter et al. 1988, Sogge et 
al. 1993, Muiznieks et al. 1994). Therefore, tamarisk invasion likely 
represents replacement of native habitat with lower-quality habitat, 
rather than an increase in habitat availability. Only in a few unique 
situations does tamarisk truly represent ``new'' habitat. For example, 
in the Grand Canyon flycatchers nest in a ``new'' riparian habitat, 
dominated by tamarisk (Carothers and Brown 1991). This new riparian 
habitat became established in the historic flood-scour zone of the 
Colorado River, after construction of Glen Canyon Dam eliminated annual 
scouring floods. However, flycatchers nest in this area in low numbers 
(Brown 1991, Sogge and Tibbitts 1992, Sogge et al. 1993) and have low 
nesting success. It is noteworthy that by forming Lake Powell, Glen 
Canyon Dam also inundated habitat in Glen Canyon. The southwestern 
willow flycatcher was described as a common nester in Glen Canyon prior 
to inundation (Behle and Higgins 1959, Behle 1985), indicating that 
this historic habitat was of higher quality than the new habitat in 
Grand Canyon.
    Issue 4: The flycatcher has always been a rare bird, so its rarity 
now is no change from historical situations; historical specimens are 
few, indicating the bird was always rare; population data are 
insufficient to show decline; population data are suspect, developed by 
parties with agendas of land control/acquisition; the flycatcher is not 
declining in all areas; historical taxonomic questions may confuse 
population trend information; accuracy or existence of population trend 
data for the last 50 years is questionable; population sampling 
techniques were not discussed; these could bias trend studies; 
population data are incomplete; the proposal relies on data reflecting 
loss of habitat rather than comprehensive population trend analysis; 
there are no recent collections of E. t. extimus from southern Arizona 
riparian areas.
    Service Response: The Service agrees that the flycatcher has 
probably always been sparsely distributed, as a function of the sparse 
distribution of its wetland habitat in a predominantly xeric region. 
However, sparse distribution and rarity are not necessarily equivalent. 
At individual locales the flycatcher may occur in considerable numbers, 
as indicated by Herbert Brown's collection of 36 nests near Yuma in 
1902, and the persistence of several populations of considerable 
numbers (30-40 pairs) in relatively small areas like the Kern River 
Preserve in California (Harris et al. 1986, Whitfield 1990). Although 
E. t. extimus habitat is rare, where it is present nesting pairs may 
occur in relatively high densities. This phenomenon has caused some 
authors to describe E. t. extimus as something of a colonial nester 
(e.g., Unitt 1987).
    Regarding the lack of historic or recent specimens available from 
various parts of the bird's range, the Service notes that specimen 
collection is largely a function of collecting activity, not simple 
presence of the subject.
    The Service agrees that, as with many non-game species, population 
trend data are incomplete. No wide scale, and few local studies have 
been funded or undertaken to track this species through time. 
Comprehensive, long-term population data are not necessarily required 
for making listing determinations. Rather, these decisions often rest 
upon data on loss and modification of habitat and other threats, which 
are reasonably assumed to result in population declines. In many cases, 
population declines are inferred from decline in habitat availability. 
However, in this and other listing determinations, the Service seeks to 
measure such inference against whatever population trend data are 
available. Regarding concerns over sources of these data, the Service 
endeavors to verify accuracy and credibility of data. The reports 
published by government agencies, academic institutions, and 
professional journals on which this determination is based are accepted 
as credible. To interpret population trends in the light of changing 
taxonomic status, the Service considered all information for willow 
flycatchers in the current range of E. t. extimus to be relevant.
    Issue 5: Livestock grazing is not a threat to E. t. extimus or its 
habitat; Montgomery et al. (1985) found 53 singing birds in a grazed 
area in New Mexico; on Marine Corps Base Camp Pendleton, E. t. extimus 
is increasing where sheep graze; nest disturbance by cattle is 
unsubstantiated; southwestern flora evolved with large grazing 
ungulates; the proposed rule lacks examples of flycatcher status 
improving with reduction in livestock or improved livestock management; 
E. t. extimus is not improving in areas with no grazing; the proposed 
rule equates any livestock grazing with overgrazing, and fails to 
distinguish between overgrazing and well-managed grazing; proper 
livestock management is compatible with healthy riparian habitat; some 
level of livestock grazing is compatible with/necessary for healthy 
riparian ecosystems; willows are brush, which cattle don't eat, but 
cattle are blamed for both brush encroachment and brush destruction; 
cattle trample stream banks, which allows water to escape, creating 
more riparian habitat; livestock grazing prevents urbanization of land, 
which would have a greater impact on riparian habitats.
    Service Response: The proposed and final rules discuss overuse by 
livestock as a threat to E. t. extimus, through impacts on riparian 
habitat. The Service recognizes that what constitutes ``overuse'' 
varies with differing riparian ecosystems, elevation, type of 
livestock, seasonality of use, and other factors. The Service believes 
that some livestock grazing regimes are likely to be found compatible 
with rehabilitation and maintenance of E. t. extimus habitat.
    Montgomery et al. (1985) did not determine whether the willow 
flycatchers they detected on grazed land were resident E. t. extimus or 
migrating individuals of other subspecies. Further, neither grazing 
intensity nor nesting [[Page 10700]] success were quantified, so that 
no correlations can be made. On Camp Pendleton, increases in E. t. 
extimus were concurrent with livestock (sheep) grazing but also with an 
extensive cowbird trapping program (Griffith and Griffith 1993). 
Finally, as discussed in this rule, examples exist of E. t. extimus 
(and other E. traillii subspecies) numbers and habitat increasing as a 
result of grazing reductions or other improvements in livestock 
management.
    The Service recognizes that southwestern riparian ecosystems 
evolved with native grazing ungulates (e.g., deer and elk). However, 
domestic livestock do not forage, herd or move in the same manner as 
native species. Further, elk occur at higher elevations of the 
Southwest, and are absent from the lowland river systems that 
constitute the majority of E. t. extimus habitat.
    Issue 6: Timber harvesting is not a threat to the flycatcher's 
riparian habitat.
    Service Response: The proposed rule noted that the petitioners 
claimed timber harvest caused watershed changes which could result in 
damage to riparian habitats through increasing intensity and frequency 
of floods. The petitioners presented no specific information on this 
claim. A number of experimental treatments on Southwestern forested 
watersheds have demonstrated increased peak and flood flows as a result 
of timber harvest (Tecle 1991). The degree to which timber harvesting 
has affected riparian habitats inhabited by the willow flycatcher, 
however, has not been quantified and is unknown. The Service did not 
implicate timber harvesting in the proposed rule as a major cause of 
riparian habitat loss. Rather, it pointed to that activity as one of 
many factors potentially responsible for riparian habitat loss and 
modification. Pending new information demonstrating otherwise, the 
Service still considers timber harvesting a potential threat to 
riparian habitat through loss and modification. However, the Service 
does not believe that this threat exists rangewide, nor does it believe 
that timber harvesting alone is responsible for riparian habitat loss 
or the endangered status of the southwestern willow flycatcher.
    All causal factors will be addressed in the recovery planning 
process, and through the Act's section 7 consultation process, through 
which Federal agencies will be responsible for evaluating the effects 
of activities such as timber harvest on the flycatcher's riparian 
habitat.
    Issue 7: Water impoundments have been beneficial, not detrimental; 
fluctuating flows below dams are not detrimental, in fact have 
increased riparian habitat (Glen Canyon Dam resulted in creation of 
riparian habitat in Grand Canyon); impoundments protect habitat by 
preventing catastrophic floods; the proposal had inadequate discussion 
of water impoundments as threat.
    Service Response: As discussed elsewhere in this final rule, water 
impoundments have a variety of effects on riparian habitats. The 
Service has determined that, with respect to E. t. extimus, the net 
effect of these influences is negative. For example, Glen Canyon Dam 
eliminated massive annual scouring floods in the Grand Canyon. This 
resulted in the development of a new riparian zone dominated by 
tamarisk (Carothers and Brown 1991). However, flycatchers nest there in 
very low numbers and with low nesting success (Brown 1991, Sogge and 
Tibbitts 1992, Sogge et al. 1993). In contrast, E. t. extimus was 
described as a common nester in Glen Canyon (Behle and Higgins 1959, 
Behle 1985), prior to its inundation by Lake Powell.
    Issue 8: Comments concerning the ecology of cowbirds and cowbird 
parasitism included the following: Breeding Bird Survey (BBS) data 
indicate that cowbirds have declined, not increased; the claim that 
cowbirds are associated with livestock is not supported; cowbirds are 
associated with deer and elk, not cows; the cowbird threat is a natural 
one; there is inconclusive evidence that cowbird increases are directly 
connected with livestock grazing; cowbird parasitism of E. t. extimus 
is known in areas without livestock grazing (e.g., Grand Canyon, Kern 
River); there is no correlation between livestock grazing in riparian 
areas and cowbird parasitism; Taylor (1986) showed that cowbirds were 
most abundant in areas with long-term livestock exclusion; because 
flycatchers and cowbirds are positively associated (they tend to occur 
together), flycatchers can coexist with cowbirds; there is inconclusive 
evidence that cowbird parasitism is responsible for declines in nesting 
success; cowbirds have increased as a result of increases in bird 
feeders, campgrounds, etc. and increases in wintering food/habitat; the 
proposed rule cited no studies that documented cowbird parasitism of E. 
t. extimus; citations regarding parasitism of other species are 
irrelevant. Section 4(a)(1)(E) of the Act allows listing species 
because of ``* * * natural or manmade factors affecting its continued 
existence * * *.''
    Service Response: Cowbird numbers appear to be declining only in 
the northeastern United States and southeastern Canada. Through the 27 
years of the BBS, cowbird populations have remained fairly stable, with 
a small increase in the 1970's, small decrease in the 1980's, and 
slight increase in recent years; however, the West has experienced a 
marked population increase over the last five years (Wiedenfeld 1993).
    The association of cowbirds with domestic livestock is detailed in 
the sources cited in this final rule. The Service has neither found nor 
been provided information indicating that cowbirds are associated with 
deer or elk. Other factors, including habitat fragmentation and urban/
suburban feeding, are likely to have contributed to increases in 
cowbirds. These causal factors will be important to address in the 
section 7 consultation process and the development of recovery actions. 
However, it is the threat of parasitism, regardless of cause, that in 
part necessitates listing.
    Where high parasitism rates are found in E. t. extimus nesting 
locations in areas with no livestock grazing at the nest site, there 
have been livestock nearby that provide feeding sites in close enough 
proximity to facilitate cowbird parasitism. Cowbirds may disperse up to 
7 kilometers (km) from their daily feeding/roosting sites to areas with 
host species (Rothstein et al. 1984). At the Kern River Preserve, the 
riparian habitat supporting E. t. extimus is not grazed, but the 
immediately adjacent lands are. Similarly, although livestock grazing 
does not occur in Grand Canyon National Park, open range grazing and an 
introduced bison herd occur on adjacent lands. Further, cowbirds 
concentrate at pack animal corrals at various points within the 
National Park (Johnson and Sogge 1993). Thus, flycatcher habitat may be 
ungrazed but still be affected by cowbirds, by having livestock 
concentrations nearby to serve as cowbird feeding sites.
    Cowbirds and E. t. extimus are positively associated because 
cowbirds require, and therefore associate with, prospective hosts. The 
Service finds that extensive information indicates cowbird parasitism 
negatively affects the southwestern willow flycatcher. This information 
includes specific examples of parasitism of E. t. extimus, cited in 
this rule, and examples of the effects of cowbird parasitism on other 
rare species of limited habitat. Recent information continues to 
document high parasitism rates for E. t. extimus (Sogge et al. 1993, 
Muiznieks et al. 1994), and increases in flycatcher reproduction or 
populations, concurrent with reductions in cowbird numbers (Griffith 
and Griffith 1993, M. Whitfield in litt.--1993). [[Page 10701]] 
    Issue 9: Tamarisk is not an invader species, but a successional 
stage, becoming established on recently-scoured areas; livestock do eat 
tamarisk for its salt content; the Service needs to clarify the 
positive and negative characteristics of tamarisk; tamarisk increases 
habitat availability, in fact provides high-quality bird habitat.
    Service Response: The Service found no information, and was not 
provided any information by commenters, indicating that tamarisk is 
primarily a successional stage vegetation type, rather than an invasive 
exotic. This final rule presents an updated discussion of tamarisk 
ecology, supported by additional literature references. The Service 
concurs with the consensus among published authorities that tamarisk is 
an invasive, usually dominant exotic plant, not a successional species. 
Commenters that stated livestock eat tamarisk for its salt content 
provided no supporting information. The Service's understanding of the 
literature is that cattle prefer native species over tamarisk for 
forage.
    As discussed in this rule, E. t. extimus has been documented 
nesting in tamarisk at elevations above approximately 625 m (2000 
feet). Rather than attempt to present criteria here for when tamarisk 
eradication presents a threat or a positive recovery action, the 
Service will address this issue on a case-by-case basis through the 
section 7 consultation process with other Federal agencies. This will 
allow Federal agencies the flexibility to consider individual cases in 
the light of the specific circumstances surrounding each one.
    Although Brown and Trosset (1989) suggested that tamarisk provided 
an ``ecological equivalent'' to native vegetation, they qualified this 
statement. They noted that their study involved small sample sizes, and 
that their methods differed from Whitmore's (1975, 1977), which was 
their basis for comparison with native riparian habitats. Further, 
Brown and Trosset (1989) noted that this ``ecological equivalent'' 
function may be most significant where tamarisk became established 
where no native riparian vegetation existed previously (e.g., the 
Colorado River in Grand Canyon).
    Issue 10: Herbert Brown's collection of 36 nests with eggs from the 
lower Colorado River, in 1900 and 1902, indicates overcollection for 
science may have caused declines.
    Service Response: The effects of Brown's collections on populations 
over 90 years ago are unknown. These effects may have been significant. 
However, Brown's collections themselves may suggest that populations at 
that time could sustain such collecting pressure. The origin of Brown's 
collections from several specific locales suggests that E. t. extimus 
was an abundant nesting bird in the area of the confluence of the Gila 
and Colorado rivers. Collection of 36 nests would have impacted 
reproduction alone, only for 1902, when all but one of the nests was 
collected. Considering continued habitat loss, and increasing cowbird 
populations since 1902, the Service does not believe that Brown's 
collection of 36 nests with eggs in 1900 and 1902 significantly affects 
E. t. extimus populations in 1995. However, the Service believes that 
current flycatcher populations are unlikely to be able to sustain 
collecting pressures like Brown's activities of 1902. In 1993, 
extensive surveys of the region of Brown's collections located only 
four to five territories (Muiznieks et al. 1994).
    Issue 11: Drought has impacted habitat.
    Service Response: The Service recognizes that extended droughts are 
likely to have impacted E. t. extimus through habitat reduction. This 
natural phenomenon and human-induced habitat impacts may exacerbate one 
another's effects on E. t. extimus habitat.
    Issue 12: Predators such as snakes, hawks, ravens, grackles, and 
domestic cats are threats to E. t. extimus.
    Service Response: The Service agrees that these constitute 
potential predators of songbirds, including E. t. extimus. While 
predation would not normally be expected to be a major threat to the 
flycatcher, its populations may be so low currently that they cannot 
withstand normal predation. Further, several of these types of 
predation may be facilitated by habitat alteration or other human 
actions. Therefore, the Service will address predation in recovery 
planning, and other Federal agencies should consider the effects of 
their actions on some of these forms of predation.
    Issue 13: Hikers, elk, deer, and beaver are threats to flycatcher 
nests and habitat; listing would cause restrictions on fishing and 
water recreation.
    Service Response: No information was provided to support statements 
that hikers constitute a threat to E. t. extimus. This rule briefly 
discusses possible impacts of recreation on E. t. extimus and its 
habitat. These impacts are expected to be primarily effects on 
vegetation through soil compaction, clearing vegetation, and creating 
trails. Because E. t. extimus is not a timid species, disturbance is 
expected to be an impact only when continuous intrusive activities take 
place near habitat, or when recreation takes place within or adjacent 
to the nest stand. Because nest stands tend to be very dense, virtually 
impenetrable thickets, often with swampy conditions, recreational 
impacts are not expected to occur often.
    Elk and deer use riparian habitats for foraging, but generally 
behave differently than domestic livestock. They tend not to occur in 
large concentrations and remain in riparian areas for long periods like 
domestic cattle. The Service is aware that elk can impact riparian 
systems when their numbers reach high levels. However, elk are lacking 
from the majority of southwestern willow flycatcher habitats, because 
these riparian areas occur at lower elevations than elk. Beaver cut and 
use willow and cottonwood, but may also be important in creating quiet-
water riparian habitats by damming smaller and steeper creeks.
    Issue 14: The presence of unoccupied habitat indicates that E. t. 
extimus is not currently habitat limited.
    Service Response: As discussed in this rule, the Service has 
determined that E. t. extimus has suffered extensive habitat loss, 
which is complicated by the current low number of flycatchers, and 
reduction of reproductive output due to brood parasitism by brown-
headed cowbirds. The current existence of apparently suitable habitat 
that is not occupied by E. t. extimus more likely indicates that its 
numbers are too low to fill all available habitat. Further, habitat 
exists in isolated, fragmented patches. With low population numbers and 
inhibited reproduction, E. t. extimus may be unable to maintain local 
populations, much less be able to disperse and colonize unoccupied 
locales.
    Issue 15: Cowbird parasitism is the main threat to E. t. extimus, 
not habitat loss; cowbird control is the primary recovery need, not 
habitat protection; cowbird trapping would eliminate the need for 
designating critical habitat; the Service should implement and fund 
cowbird control programs instead of listing.
    Service Response: The Service has determined that cowbird 
parasitism is one of several primary threats to E. t. extimus, which 
also includes the loss and modification of habitat. Cowbird parasitism 
and loss and modification of habitat are interrelated. Cowbird 
parasitism is a function not just of cowbird abundance, but also 
habitat quality. Potential host species in degraded, fragmented habitat 
are more susceptible to nest parasitism than those nesting in larger 
tracts of dense, contiguous habitat. Cowbird parasitism 
[[Page 10702]] will probably remain an imminent threat until habitat 
rehabilitation is accomplished. The Service acknowledges that cowbird 
control should be an immediate, high priority recovery action. However, 
cowbird control is a ``stop-gap'' action. Rehabilitating riparian 
habitat to make E. t. extimus and other riparian birds less susceptible 
to cowbird parasitism will be necessary for a long-term solution. 
Ultimately, the ranking of threats in order of severity is not relevant 
to the listing question. It is because a number of often interdependent 
threats exist that listing E. t. extimus is necessary. Ranking threats 
in order of severity and addressing them accordingly will be part of 
the recovery process.
    Issue 16: Willow flycatchers nesting in the northern States, 
Alaska, and Canada are subspecies other than E. t. extimus. The 
boundaries of the breeding range of E. t. extimus should be expanded to 
include the Santa Ynez River in California, and the Green and Colorado 
River systems in west-central Utah; E. t. extimus does not occur in 
Utah, Colorado, or the Carson National Forest in northern New Mexico; 
the willow flycatcher is common in the northern States, Alaska, Canada, 
most of the U.S., Mexico and Panama; caution should be exercised in 
defining range limits of the subspecies, including elevational limits.
    Service Response: Two primary authorities (Unitt 1987, Browning 
1993) provide the range limits of E. t. extimus identified in this rule 
(see Figure 1). The Service also considered other information, such as 
historical nesting records, habitat characteristics, and proximity to 
neighboring populations of E. t. extimus or other willow flycatcher 
subspecies. Using this information, the Service provisionally defines 
the northwestern limit of the subspecies' range to be the Santa Ynez 
River in California. Willow flycatchers nesting along the Santa Ynez 
River occupy lowland riparian habitat similar to other coastal 
California locations of E. t. extimus, and few willow flycatcher (i.e., 
E. t. brewsteri) nesting locales are known in coastal California for a 
considerable distance north of the Santa Ynez River.
    Browning (1993) found no evidence of intergrades between E. t. 
extimus and E. t. adastus in Utah. The northern limit of E. t. extimus 
in Utah is believed to correspond closely to the area comprising the 
following counties: Garfield, Kane, San Juan, Washington, and Wayne. 
This area takes in stretches of riverine riparian habitat in southern 
Utah that have historical records of flycatchers and that still have 
potential willow flycatcher habitat.
    The Service recognizes that taxonomic questions may arise 
concerning flycatchers occupying some high-elevation locales within the 
range of E. t. extimus. Because the genetic relatedness of willow 
flycatchers breeding at some high elevation areas, such as the White 
Mountains of Arizona, may be substantial, willow flycatchers in those 
locales should be considered E. t. extimus until further research 
demonstrates otherwise. Protection of these breeding groups could be 
critical for population recovery, immigration, and exchange of genetic 
material within a highly-fragmented landscape.
    Issue 17: It is inappropriate to use data from E. t. brewsteri and 
E. t. adastus to support listing E. t. extimus; information cited on 
livestock damaging nests comes from other subspecies.
    Service Response: The Service carefully considered the propriety of 
using information on other willow flycatcher subspecies in evaluating 
the listing question for E. t. extimus. In applying such information, 
the Service considered ecological similarities and dissimilarities 
between the subspecies. The Service believes that data from other 
subspecies are applicable in some cases, but not others. The Service 
has identified which subspecies provided data sources throughout the 
proposed and final rules. The phenomenon of livestock damaging nests 
and/or contents through physical contact is known for willow flycatcher 
subspecies other than E. t. extimus. This threat was noted to recognize 
that the potential exists, where nests occur low enough in vegetation 
or in other vulnerable locations, that livestock, humans, or other 
animals may contact them or the nest plant.
    Issue 18: Habitat in California was lost to urbanization, not 
livestock; the proposed rule had inadequate discussion of urban and 
suburban development as a threat; urban development is not a threat to 
some populations.
    Service Response: Loss and modification of the riparian habitat of 
E. t. extimus is the result of numerous factors, discussed in depth in 
this rule. Not all these factors have affected all riparian habitats, 
and some rare habitats remain unaffected. Further, the degree to which 
these factors influence riparian habitat varies across the landscape. 
Urban and suburban development has certainly impacted some E. t. 
extimus habitats. These impacts may result from direct encroachment and 
channelization of riparian habitats, as in coastal southern California 
and central Arizona. Urban and suburban development also increase 
demands on river systems for water and hydropower. Thus, expanding 
urban centers can result in dewatering or alteration of riparian 
systems tens or hundreds of miles away. For example, the water and 
power demands of Los Angeles, Phoenix and Las Vegas result in effects 
on the Colorado River hundreds of miles from any of these cities.
    Issue 19: The primary threat to E. t. extimus is loss of wintering 
habitat in Central and South America, or other factors along migration 
routes; the proposed rule contained insufficient information on 
migration studies; protecting breeding grounds is not logical, because 
E. t. extimus spends eight months of the year in migration or on 
wintering grounds.
    Service Response: Although tropical deforestation possibly may 
restrict wintering habitat of the willow flycatcher, the best available 
current information on the subject suggests otherwise. The limited data 
on willow flycatcher wintering habitat indicates that this species uses 
``* * * brushy savannah edges and second growth'' in Costa Rica (Stiles 
and Skutch 1989); in Panama it has been documented in ``shrubby areas'' 
(Ridgely 1981); and in South America it has been documented in ``* * * 
shrubby clearings, pastures, and lighter woodland'' or ``* * * on 
islands with early successional growth'' (Ridgely and Tudor 1994). 
Given existing land use practices in Central and South America, which 
are characterized by conversion of old-growth forested habitat to 
agricultural and second-growth habitats, few if any of the winter 
habitat types in which willow flycatchers have been documented should 
currently be in jeopardy.
    Issue 20: The Service cannot define nesting habitat; habitat 
requirements are poorly understood; the proposed rule's description of 
nesting habitat is flawed and inadequate to direct management; the 
minimum patch size necessary to support a nesting pair of E. t. extimus 
is 1 to 1.5 hectares.
    Service Response: The Service believes the proposed rule and this 
final rule accurately compile and summarize the existing information on 
E. t. extimus nesting habitat, and that information is sufficient to 
identify, conserve, and recover the riparian ecosystem of which E. t. 
extimus is a part. Habitat patches occupied by E. t. extimus vary 
somewhat in size, floristic composition, vegetation structure, and type 
of wetland. Therefore, the Service believes it is inappropriate and 
inaccurate to [[Page 10703]] narrowly define suitable habitat in terms 
of plants per unit area, vegetation density, specific plant community 
composition, type and volume of surface water, and patch size. The 
Service has no information to indicate inaccuracy or inadequacy of the 
habitat description presented in this rule. Specifically regarding 
patch sizes, one to two E. t. extimus pairs have been observed nesting 
in habitat patches of 0.5 ha (Sogge et al. 1993, Sogge et al. unpubl. 
1994 data); therefore 1.0 to 1.5 ha is not an accurate estimate of the 
minimum patch size needed to support a single nesting pair.
    Issue 21: Habitats used by nesting pairs differ from those used by 
single, unmated, wandering, or migrant flycatchers; the latter face 
minimal threats and are not essential to conservation of the species.
    Service Response: The commenters provided no data supporting the 
statement that habitats used by unpaired E. t. extimus differ from 
nesting habitat, and the Service found no indication of this in the 
available literature. Unmated, resident E. t. extimus have been found 
in habitats identical to nearby habitats occupied by nesting pairs 
(Sogge and Tibbitts 1992, Sogge et al. 1993). The Service believes that 
single, unmated E. t. extimus also face threats of habitat loss, and 
that conservation of these individuals is essential to the conservation 
of the species, particularly at the low current numbers of flycatchers.
    Issue 22: Listing constitutes single-species management that will 
damage other species; E. t. extimus habitat is incompatible with 
habitat needs of other listed and sensitive species, particularly the 
spikedace and loach minnow.
    Service Response: The purposes of the Act are to provide a program 
for the conservation of threatened and endangered species and to 
conserve the ecosystems upon which threatened and endangered species 
depend. The Service believes that managing for E. t. extimus and other 
listed riparian and aquatic species accomplishes this purpose, to the 
mutual benefit of listed and nonlisted species alike. The intent of 
this listing is to conserve and recover E. t. extimus and the riparian 
and aquatic ecosystems of which it is a part.
    The primary constituent elements of critical habitat described for 
the spikedace (59 FR 10906) and loach minnow (59 FR 10898) are not in 
conflict with the habitat requirements for the southwestern willow 
flycatcher, and are not in conflict with the primary constituent 
elements of its proposed critical habitat (58 FR 39495). The fishes 
require ``a healthy, intact riparian community,'' which will also 
benefit E. t. extimus and other riparian and aquatic species. The 
spikedace, loach minnow, and E. t. extimus all require surface water 
and/or a high water table, a low to moderate stream gradient, and 
periodic flooding. The fishes specifically require a ``natural, 
unregulated hydrograph,'' which the Service believes would also benefit 
the flycatcher. These fish also require moderate to high bank 
stability; maintenance of the riparian vegetation on which E. t. 
extimus depends will provide such bank stability. The Service does not 
view management for E. t. extimus, spikedace, and loach minnow as 
mutually exclusive, but as mutually beneficial.
    Issue 23: Floods regenerate habitat, they do not destroy it; floods 
destroy habitat; floods, not livestock, caused much of riparian 
degradation; the proposed rule is confusing and contradictory on the 
role of floods as a threat or necessary ecological function.
    Service Response: The proposed rule stated that ``Its habitat 
rarity, and small, isolated populations make the remaining E. t. 
extimus increasingly susceptible to local extirpation through 
stochastic events such as floods * * *. In early 1993, catastrophic 
floods in southern California and Arizona damaged or destroyed much of 
the remaining occupied or potential breeding habitat. Historically, 
these floods have always destroyed habitat but were also important 
events in regenerating cottonwood-willow communities.''
    It is important to note that E. t. extimus is threatened by 
stochastic events like floods because of its current rarity and 
isolated nature of populations. If the species existed at healthy 
population levels, and if its riparian habitat were not greatly 
reduced, these natural stochastic events would not constitute threats. 
The 1993 flood events referred to were extraordinary in nature, 
described regionally as 500-year floods. Therefore, they do not typify 
flood events in the river systems involved. Further, while natural 
flood events are expected to destroy some flycatcher habitat, they are 
also crucial for regenerating natural riparian nesting habitat. In a 
healthy system where riparian vegetation is abundant and the stream 
channel is not eroded or destabilized, destruction and regeneration are 
balanced and habitat is generally available. Only when riparian 
vegetation is severely reduced and the stream channel and watershed are 
destabilized are riparian and aquatic species threatened by the 
natural, short-term habitat losses resulting from flooding.
    Issue 24: To manage for E. t. extimus, the Service will enforce or 
has proposed a fenced livestock-free corridor.
    Service Response: The Service has neither proposed nor been 
consulted regarding a fenced, livestock-free corridor established along 
riparian areas on State, Federal, or private lands.
    Issue 25: Beneficial land management practices should be recognized 
and discussed; the proposed rule fails to acknowledge that some 
habitats are protected from urban development.
    Service Response: The Service recognizes that some management 
practices are beneficial. Some practices have protected or improved 
habitat, resulted in expanded populations, and/or improved 
reproduction. The Service will look to these beneficial land management 
practices as important examples in the recovery planning process. 
However, in making a listing determination the Service must consider 
the situation across the species' entire range. It is this overall 
perspective that drives the listing decision. Although some nesting 
groups of E. t. extimus may be safe, stable, or perhaps even 
increasing, the Service has determined that overall the species is 
endangered.
    Issue 26: Existing regulatory mechanisms are adequate, including: 
the Migratory Bird Treaty Act (MBTA); State listings for Arizona, New 
Mexico, and California; section 404 of the Clean Water Act; Bureau of 
Land Management and Forest Service policies; Executive Orders 11988 and 
11990; protection of riparian habitat due to presence of other listed 
species; private and/or cooperative management plans at local areas.
    Service Response: The Service considered these regulatory 
mechanisms and management plans, and determines that overall existing 
regulatory mechanisms are insufficient to conserve and recover E. t. 
extimus in the face of the primary threats of loss and modification of 
habitat and cowbird parasitism. A full discussion of Federal and State 
protection is found in this document under Factor D: ``Inadequacy of 
existing regulatory mechanisms''.
    The Service recognizes that some local management plans benefit and 
conserve E. t. extimus and its habitat. Examples include management of 
the Bureau of Land Management's San Pedro Riparian National 
Conservation Area (SPRNCA) in Arizona, where six years of livestock 
exclusion have resulted in significant restoration of riparian habitats 
and increases in birds associated with habitats similar to E. t. 
extimus (Krueper 1993). Willow [[Page 10704]] flycatchers have not yet 
returned to their historical locations on the SPRNCA but may soon. 
Habitat protection and cowbird management at The Nature Conservancy's 
Kern River Preserve and on Marine Corps Base Camp Pendleton in 
California have improved habitat and reduced brood parasitism pressures 
for resident E. t. extimus (Griffith and Griffith 1993). Wetland 
management at Bosque del Apache National Wildlife Refuge in New Mexico 
is apparently sustaining a small population of flycatchers. While these 
actions are beneficial, they provide for E. t. extimus only at several 
locales. Further, long-term continuation of these management actions is 
not assured.
    Provisions of section 404 of the Clean Water Act do not 
specifically protect E. t. extimus or its habitat, but do provide some 
protection to the aquatic and riparian ecosystems of which it is a 
part. Section 404 of the Clean Water Act also provides for mitigation 
of destruction of these habitats, however, allowing even temporary 
destruction of riparian habitat is not consistent with the immediate 
conservation needs of E. t. extimus.
    Issue 27: The Service did not use the best available scientific or 
commercial information in making this determination; the Service 
presented insufficient and inconclusive information to support listing; 
the proposed rule used information which was general, incomplete, and 
originated with other flycatcher subspecies; the proposed rule was 
premature; the Service did not adequately solicit information and 
public input; scientific, economic, biological, hydrological and 
botanical data must support listing; how does the Service know the 
scientific information supporting listing was right?
    Service Response: The Service canvassed the published literature 
regarding the taxonomy, ecology, and biology of the southwestern willow 
flycatcher, and the threats to it and its habitat. Because numerous and 
complex phenomena and processes were involved, this information ranged 
from general (e.g., wide scale trends in riparian habitat) to very 
specific (status of nesting groups). The Service believes it used the 
best available information, and has determined that this information is 
adequate to support listing. The Service evaluates sources before using 
or discounting information. In general, the Service expects that 
publications in peer-reviewed scientific journals, reports from land 
and resource management agencies, and dissertations or reports from 
academic or research institutions have undergone technical review. 
Other information sources are considered more anecdotal, and the 
Service seeks to confirm such information before using it.
    Issue 28: The Service should comply with the National Environmental 
Policy Act (NEPA) by completing an Environmental Impact Statement 
(EIS), and comply with 40 CFR 1506 to reduce duplication between NEPA 
and State and local requirements; the Service should comply with 40 CFR 
1508.20 to compensate for producing substitute resources or 
environments; the Service should engage in joint planning with local 
governments under NEPA regulations.
    Service Response: As noted in this final rule, the Service has 
determined that an Environmental Assessment, as defined under the 
authority of NEPA, need not be prepared for listing actions. A notice 
outlining the Service's reasons for this determination was published in 
the Federal Register on October 25, 1983 (48 FR 49244). Because of this 
determination, an EIS also need not be prepared. Also because of this 
determination, reduction of duplication between the NEPA process and 
State and local agencies, and joint planning between those agencies and 
the NEPA process, are rendered moot.
    Issue 29: The proposed rule violates the Regulatory Flexibility 
Act; no Regulatory Impact Analysis/Assessment as required under 
Executive Orders 12291 and 12866 was completed; it also may be 
inconsistent with the mandates of other agencies.
    Service Response: Decisions on listing and reclassification under 
the Act are made based on five factors defined in section 4(a)(1) of 
the Act. These five factors are discussed in this rule, as they relate 
to E. t. extimus. The Act requires the Service to consider only 
scientific and commercial information relating to these five factors in 
making listing determinations, not economic information. Economic 
information is considered in designating critical habitat, which is not 
part of this rule. Therefore, compliance with the Regulatory 
Flexibility Act and Executive Orders 12291 and 12866 is not an issue 
for this action, but will be addressed if a critical habitat 
designation is made (H.R. Conf. Rep. No. 835, 97th Cong., 2d Sess. 20 
(1982); accord, S. Rep. No. 418, 97th Cong., 2d Sess. 4 (1982)).
    Where conservation and recovery of threatened and endangered 
species is inconsistent with other mandates of Federal agencies, 
processes under section 7 of the Act serve to evaluate projects arising 
from those mandates, with regard to protection of listed species. 
However, section 2(c) of the Act requires all Federal departments and 
agencies to conserve listed species and further the purposes of the 
Act.
    Issue 30: The Service should complete a Takings Implications 
Assessment prior to listing/designating critical habitat.
    Service Response: The Service will complete a takings analysis for 
any final designation of critical habitat in compliance with Executive 
Order 12630 and the Attorney General's supplemental guidelines issued 
June 30, 1988. In accordance with those guidelines and Interior 
Department policy, this analysis will be completed after listing, not 
as part of consideration of the listing determination itself.
    Issue 31: Requests were received for local public hearings.
    Service Response: The proposed rule stated that three public 
hearings would be held. Because of many requests for additional 
hearings, a total of six public hearings were held. Regulations at 50 
CFR 424.16(c)(3) require the Service to hold one public hearing if 
requested.
    Issue 32: The time allowed for public comments was inadequate; the 
proposal should have been subjected to peer review.
    Service Response: The Service is required to accept public comments 
for at least 60 days regarding proposals to list and/or designate 
critical habitat (50 CFR 424.16(c)(2)). In this case the Service 
initially announced a 90-day public comment period, then extended that 
another 40 days for a total of 130 days (July 23, 1993 through November 
30, 1993). Public comment periods and public hearings are the 
mechanisms by which the Service receives input from all interested 
parties, including scientific peer review.
    Issue 33: Listing would require private property owners to consult 
with the Service on their actions; listing and/or designating critical 
habitat constitute take of private property rights; adverse 
modification of critical habitat would be prohibited on private lands; 
the Service failed to notify the affected public of the consequences of 
adverse modification of critical habitat; listing and/or designating 
critical habitat may affect civil rights.
    Service Response: Listing does not require private property owners 
to consult with the Service on actions which may affect a listed 
species. However, section 7 of the Act does require Federal agencies to 
consult on actions which they fund, permit, or carry out if those 
actions may affect a listed species or adversely modify critical 
habitat. Any potential take of private property will be analyzed in 
compliance with Executive Order 12630 [[Page 10705]] (see Issue 30). As 
discussed later (Issue 35), because critical habitat is not being 
designated with this rule, comments regarding critical habitat will be 
addressed during subsequent actions regarding critical habitat.
    Issue 34: Requests were received to be on a mailing list for all 
actions relating to this issue or to be provided personal notification 
of a final decision.
    Service Response: The Service tries to maintain mailing lists for 
specific issues whenever possible. However, when large numbers of 
parties request to be on such lists, it becomes logistically and 
financially unfeasible to mail information to each party. This issue is 
one of those, and the Service must rely to some degree on mass 
communication forums like news releases, public notices in newspapers, 
and publications in the Federal Register.
    Issue 35: Numerous comments were received regarding critical 
habitat.
    Service Response: Critical habitat for E. t. extimus is not being 
designated with this rule; therefore, the above issues are not 
addressed here. Designation of critical habitat is being deferred while 
the Service further considers the extent to which designation is 
appropriate. Issues pertaining to this designation will be addressed 
when a final decision is made with regard to the critical habitat 
proposal.
    Issue 36: Numerous comments were received regarding recovery of E. 
t. extimus, including: the Service has no recovery plan for E. t. 
extimus; the proposed rule failed to identify recovery goals for 
habitat, flycatcher numbers, and flycatcher distribution; the proposed 
rule failed to identify what actions will be used to achieve recovery; 
a recovery plan should address control of cowbird parasitism, nest 
damage by livestock, tamarisk eradication, wintering habitat, 
monitoring populations, protection of public and private lands from 
fire; cowbird parasitism cannot be addressed by listing and designating 
critical habitat; cowbirds are not easily controlled without 
sacrificing flycatchers and/or impacting habitat; the proposed rule 
contained no livestock managing strategy; rotating livestock will allow 
habitat enhancement/recovery; the factors affecting riparian habitats 
are numerous and complex; failure to address all could be futile or 
have damaging effects.
    Service Response: Section 4(f) of the Act authorizes the Service to 
develop and implement recovery plans for listed species, not species 
that are proposed for listing. For E. t. extimus, this process 
therefore begins with the effective date of listing. In accordance with 
section 4(f)(B) of the Act the recovery plan process will address 
actions necessary to achieve conservation and recovery of E. t. 
extimus, will identify measurable criteria by which recovery (i.e., the 
point at which protection under the Act is no longer necessary) can be 
gauged, and will identify the time and costs required to achieve 
recovery. The specific issues identified above will be considered in 
developing a recovery plan, and that plan will be available for public 
review and comment prior to adoption. Monitoring species is frequently 
an element of recovery plans, and is also required by section 4(g) of 
the Act for any species deemed to be recovered.
    Issue 37: Several commenters questioned the motivations of the 
petitioners in requesting the listing, and others apparently believed 
the petitioners authored the listing proposal. Several commenters noted 
that the petition contained inaccuracies, and therefore no listing 
proposal should have resulted.
    Service Response: The Service cannot speak for the petitioners' 
motivations in requesting listing of E. t. extimus. The Service judged 
the petition solely on the scientific information it contained. 
Inaccuracies were found in the petition, but on the whole the Service 
determined that it presented substantial information indicating that 
listing may be warranted. The listing proposal was authored by the 
Service, not the petitioners. The Service developed its proposal not 
from the petition, but from information gained from journal 
publications, agency reports, and the general public's responses to 
several information solicitations. This status review process had 
resulted in the Service designating E. t. extimus a category 1 
candidate species prior to the petition being received. That 
designation indicated that the Service had sufficient information to 
support a listing proposal but did not publish a proposal immediately 
because it was dealing with listing actions of higher priority. 
Information presented by the petitioners that the Service did not 
already possess was checked for accuracy; information that could not be 
confirmed, or was found to be inaccurate, was not used.
    Issue 38: The Service is required to purchase interest in land or 
water for implementation of the Act; this violates the U.S. 
Constitution.
    Service Response: Section 5 of the Act directs the Secretary to use 
land acquisition and other authorities of the Fish and Wildlife Act of 
1956, as amended, the Fish and Wildlife Coordination Act, as amended, 
and the Migratory Bird Conservation Act, as appropriate. The Secretary 
is authorized, but not required, to acquire interest in land or water 
to conserve threatened and endangered species. The Service does not 
carry out these authorities in violation of the U.S. Constitution. The 
Service does not acquire all lands designated as critical habitat for a 
listed species, and does not develop critical habitat designations 
based on land ownership or interest of landowners in purchasing or 
selling properties. It is the Service's policy to acquire property only 
on a voluntary basis from willing sellers.
    Issue 39: Land use outside occupied/critical habitat will be 
adversely impacted.
    Service Response: Federal actions that take place outside occupied 
habitat or critical habitat, but that may affect E. t. extimus, will be 
subject to consultation between the action agency and the Service in 
accordance with section 7 of the Act. Exclusively private actions are 
unaffected by listing and/or designation of critical habitat, provided 
they do not result in violation of section 9 of the Act (e.g., take of 
the species).
    Issue 40: Listing (regardless of critical habitat) will have 
adverse impacts on local economy; economic impacts of listing were not 
addressed; the Act requires the Service to consider impacts on other 
wildlife species and social and economic impacts prior to listing.
    Service Response: Consideration of economic effects is required for 
designation of critical habitat. The Act requires that species listing 
decisions be based solely on the best scientific and commercial 
information available, which precludes consideration of social or 
cultural impacts or impacts on other species. (See section 4(b)(1)(A) 
of the Act). The Service anticipates no significant impacts on other 
native wildlife species as a result of listing, with the probable 
exception of the brown-headed cowbird.
    Issue 41: Who initiated, performed, and paid for studies along the 
Kern River?
    Service Response: Reports on studies done on the Kern River were 
published by Harris et al. (1986), Harris et al. (1987), Whitfield 
(1990), and Harris (1991). Specific information on project 
participants, funding sources, and cooperators can be found in those 
sources. The Service understands that monitoring and cowbird control 
are being continued by the Kern River Research Center and The Nature 
Conservancy, with funding assistance from the State of California and 
the Service. [[Page 10706]] 
    Issue 42: The Service should perform additional surveys before 
listing.
    Service Response: The Service is supporting continuing surveys to 
detect additional E. t. extimus, to monitor known nest sites, and to 
evaluate habitat presence, quality, and distribution. The Service 
supports these surveys with funding to States in accordance with 
section 6 of the Act, and through logistical and technical assistance 
to other agencies and parties. Extensive surveys in New Mexico and 
Arizona in 1993 located E. t. extimus in numbers that do not 
significantly change the total population estimates made in the 
proposed rule. These surveys also confirmed high levels of brood 
parasitism by cowbirds. With low estimates of total flycatcher numbers 
being validated by continuing surveys, the Service has determined that 
sufficient information exists on the threats of habitat loss and 
cowbird parasitism to justify listing.
    Issue 43: The Service failed to consult adequately with private 
interests, State, Federal, and local agencies prior to publishing the 
proposed rule.
    Service Response: The Service published public requests for 
information on the status of E. t. extimus in the Federal Register when 
it was designated a category 2 candidate species in January 1989, and 
when it was designated a category 1 species in November 1991. The 
Service supplemented these requests with general mailings soliciting 
information, and information solicitations in professional 
publications. Beyond these mechanisms, the Service is constrained by 
funding limitations and citizens' suits such as Environmental Defense 
Center, Inc. vs. Babbitt et al. IV 93-1848-R (C.D. Calif.), which was 
brought to compel the Service to propose listing and designation of 
critical habitat for the species, that preclude individually contacting 
every interested party.
    Issue 44: The parties who petitioned for listing should pay for 
studies supporting their request.
    Service Response: Regulations implementing section 4 of the Act, 
specifically the petition process [50 CFR 424.14], do not require 
petitioners to fund studies supporting their request. Listing 
determinations are made if existing information is deemed sufficient to 
make a determination. This information typically originates from a 
variety of sources.
    Issue 45: The southwestern willow flycatcher is abundant. There is 
no need to list.
    Service Response: The Service has determined that E. t. extimus is 
rare, not abundant, faces serious threats to its continued existence, 
and warrants listing as endangered. See discussion under Factor A: The 
present or threatened destruction, modification, or curtailment of its 
habitat or range.
    Issue 46: The ``little'' willow flycatcher (E. t. brewsteri) is the 
most common subspecies observed and collected in the Southwest.
    Service Response: The abundance of collections of E. t. brewsteri 
from within the breeding range of E. t. extimus is because E. t. 
brewsteri migrates through the Southwest between its Pacific coastal 
breeding range and wintering grounds in Central America. E. t. 
brewsteri passes through riparian habitats in the breeding range of E. 
t. extimus in spring and fall, but does not breed there.
    Issue 47: There is no need to list E. t. extimus in areas where it 
is doing well.
    Service Response: The Service has determined that E. t. extimus is 
endangered; local areas where the bird is relatively stable could only 
be excluded from listing or classified as threatened if they 
constituted distinct population segments [50 CFR 424.02(k)]. The 
Service has not identified any distinct population segments of E. t. 
extimus. Further, because the Service determines E. t. extimus to be 
endangered, all existing habitat and local nesting concentrations are 
deemed to be essential to the conservation and recovery of the species. 
Protection of locales where the bird is doing relatively well may be 
especially important for the conservation and recovery of E. t. 
extimus.
    Issue 48: Prey availability may be a limiting factor.
    Service Response: The Service recognizes that food availability is 
always a potential limiting factor in wildlife populations. It is 
possible that reduction of riparian habitats not only reduced 
vegetation for nesting, but reduced or altered the arthropod fauna 
associated with surface water and extensive vegetation. Also, as noted 
in this rule, some speculation exists that tamarisk provides a 
substandard nesting habitat because it supports a significantly 
different insect fauna than native vegetation. However, no information 
was available to evaluate this factor directly for E. t. extimus.
    Issue 49: Several comments were received that pertained to the 
Service's management of the 90-day petition finding, including that the 
90-day petition finding was late; that it is not the Service's role to 
conduct a status review if information in a petition is lacking; and 
that a 30-day comment period on the 90-day petition finding was 
insufficient.
    Service Response: The Service acknowledges that its finding on the 
listing petition was published after 90 days, however, the Act (section 
4(b)(3)(A) states that the [Service] shall, to the maximum extent 
practicable, make a petition finding within 90 days (emphasis added). 
Because the petition was found to present substantial information 
indicating that the petitioned action may have been warranted, the 
Service continued a status review after this finding, in accordance 
with 50 CFR 424.14(b)(3). There are no requirements for the Service to 
open a formal comment period regarding a 90-day petition finding. The 
Service did so in this case to solicit additional information on E. t. 
extimus. In reaching its 12-month petition finding, the Service 
considered all information received within the 30-day period 
identified, and information received for several months thereafter.
    Issue 50: E. t. extimus should be listed as threatened, not 
endangered.
    Service Response: The Service carefully evaluated the status of E. 
t. extimus and has determined that it meets the definition of an 
endangered species, not a threatened species. As stated in the proposed 
rule, (58 FR 39495) threatened status would not be appropriate because 
the large historic habitat loss already has caused extirpation 
throughout a significant portion of the species' range. Population 
numbers are extremely low, and a variety of threats are serious and 
imminent.
    Issue 51: Restrictions on rural livestock grazing will cause 
ranching to become nonviable, and the land will be converted by 
suburban development, which is a greater threat to E. t. extimus than 
overgrazing.
    Service Response: The conversion of lands from livestock grazing to 
suburban development is hypothetical and therefore cannot drive the 
Service's determination on this issue. Much of the livestock grazing 
that may be affected by this rule takes place on Federal lands.
    Therefore, conversion to suburban development would require land 
exchanges or sales. These actions, if they were determined to affect E. 
t. extimus, would require consultation under section 7 of the Act. 
Regardless, prioritization of threats should be undertaken in the 
recovery, rather than listing, process.
    Issue 52: The proposed rule fails to consider changing ecological 
factors: drought, migration patterns, nesting habits, and climatic 
changes. [[Page 10707]] 
    Service Response: The Service recognizes that populations of E. t. 
extimus are likely to fluctuate naturally in response to various 
ecological factors. However, the Service believes that declines in 
habitat availability and increased exposure to cowbird parasitism have 
caused population reductions beyond the scale of natural fluctuations. 
Fluctuations in response to nonanthropogenic phenomena are likely to 
continue, but the current population levels are so low that these 
natural phenomena may be sufficient to cause local extirpations.
    Issue 53: Restrictions associated with listing would be in conflict 
with Kern County's General Plan.
    Service Response: Under section 4 of the Act, the Service considers 
only scientific and commercial information relating to the five listing 
factors outlined in section 4(a)(1) and discussed with respect to E. t. 
extimus in this rule. Therefore, conflicts with local plans were not 
considered in making this determination. However, the Service strives 
to pursue conservation and recovery of listed species in cooperation 
with State and local authorities, and seeks to minimize conflicts.
    Issue 54: Listing and critical habitat designations will adversely 
affect flood control measures, some authorized by the Federal Emergency 
Management Agency and other Federal and State regulations; the proposed 
rule failed to consider flood accommodation needs, channelization, and 
clearing vegetation.
    Service Response: Flood control measures virtually always involve a 
Federal agency, through funding, permitting, and/or other action. 
Therefore, flood control measures that may affect E. t. extimus would 
undergo consultation under section 7 of the Act. Section 7 and its 
implementing regulations have provisions for emergency consultations, 
and for actions within presidentially declared disaster areas.
    Issue 55: Government agencies are responsible for many impacts to 
riparian areas; campgrounds, fish hatcheries, and some district offices 
are located in riparian areas.
    Service Response: The Service acknowledges that some Federal 
actions are in part responsible for the threats facing E. t. extimus. 
As a result of listing, those Federal actions will be subject to 
consultation under section 7 of the Act to evaluate and minimize the 
effects of those actions.
    Issue 56: The Service does not acknowledge receipt of comments on 
listing, and probably does not read them.
    Service Response: The Service does not routinely acknowledge 
receipt of each letter commenting on listing proposals. The number of 
letters in this case made it logistically and financially impossible to 
acknowledge each one. However, all letters were read, and their issues 
addressed either here or elsewhere in this final rule. All comment 
letters and transcripts of public hearings are retained in the 
permanent file on this species and are available for public inspection.
    Issue 57: Protecting flycatcher habitat may restrict mosquito 
control, which is important for control of encephalitis and other 
mosquito-borne diseases.
    Service Response: Where such control involves a Federal action, 
mosquito and disease control actions may be subject to consultation 
under section 7(a)(2) of the Act, which would evaluate but not 
necessarily restrict or significantly modify the project. Ultimately, 
section 7(e) of the Act allows exemptions to the requirements of 
section 7(a)(2).
Summary of Factors Affecting the Species

    After a thorough review and consideration of all information 
available, the Service has determined that the southwestern willow 
flycatcher should be classified as an endangered species. Procedures 
found at section 4(a)(1) of the Act and regulations implementing the 
listing provisions of the Act (50 CFR Part 424) were followed. A 
species may be determined to be an endangered or threatened species due 
to one or more of the five factors described in section 4(a)(1). These 
factors and their application to the southwestern willow flycatcher 
(Empidonax traillii extimus) are as follows:

A. The Present or Threatened Destruction, Modification, or Curtailment 
of its Habitat or Range

    Large scale losses of southwestern wetlands have occurred, 
particularly the cottonwood-willow riparian habitats of the 
southwestern willow flycatcher (Phillips et al. 1964, Carothers 1977, 
Rea 1983, Johnson and Haight 1984, Katibah 1984, Johnson et al. 1987, 
Unitt 1987, General Accounting Office (GAO) 1988, Bowler 1989, Szaro 
1989, Dahl 1990, State of Arizona 1990, Howe and Knopf 1991). Changes 
in riparian plant communities have resulted in the reduction, 
degradation, and elimination of nesting habitat for the willow 
flycatcher, curtailing the ranges, distributions, and numbers of 
western subspecies, including E. t. extimus (Gaines 1974, Serena 1982, 
Cannon and Knopf 1984, Klebenow and Oakleaf 1984, Taylor 1986, Unitt 
1987, Schlorff 1990, Ehrlich et al. 1992).
    Dahl (1990) reviewed estimated losses of wetlands between 1780 and 
the 1980's in the Southwest: California is estimated to have lost 91 
percent, Nevada 52 percent, Utah 30 percent, Arizona 36 percent, New 
Mexico 33 percent, and Texas 52 percent. As much as 90 percent of major 
lowland riparian habitat has been lost or modified in Arizona (State of 
Arizona 1990). Franzreb (1987) noted that ``[B]ottomland riparian 
forests are the most highly modified of natural landscapes in 
California.''
    Loss and modification of southwestern riparian habitats have 
occurred from urban and agricultural development, water diversion and 
impoundment, channelization, livestock grazing, off-road vehicle and 
other recreational uses, and hydrological changes resulting from these 
and other land uses. Rosenberg et al. (1991) noted that ``it is the 
cottonwood-willow plant community that has declined most with modern 
river management.'' Loss of the cottonwood-willow riparian forests has 
had widespread impact on the distribution and abundance of bird species 
associated with that forest type (Hunter et al. 1987, Hunter et al. 
1988, Rosenberg et al. 1991).
    Overuse by livestock has been a major factor in the degradation and 
modification of riparian habitats in the western United States. These 
effects include changes in plant community structure and species 
composition, and relative abundance of species and plant density. These 
changes are often linked to more widespread changes in watershed 
hydrology (Rea 1983, General Accounting Office 1988) and directly 
affect the habitat characteristics critical to E. t. extimus. Livestock 
grazing in riparian habitats typically results in reduction of plant 
species diversity and density, especially of palatable broadleaf plants 
like willows and cottonwood saplings, and is one of the most common 
causes of riparian degradation (Carothers 1977, USDA Forest Service 
1979, Rickard and Cushing 1982, Cannon and Knopf 1984, Klebenow and 
Oakleaf 1984, GAO 1988, Clary and Webster 1989, Schultz and Leininger 
1990).
    Increases in abundance of riparian bird species have followed 
reduction, modification, or removal of cattle grazing. Krueper (1993) 
found the following increases in birds associated with cottonwood-
willow habitat on Arizona's San Pedro River four years after the 
removal of livestock: yellow warbler, 606 percent; common yellow-
throat, 2,128 percent; yellow-breasted [[Page 10708]] chat, 423 
percent. Bock et al. (1993) found that 40 percent of the riparian bird 
species they examined, including the willow flycatcher (various 
subspecies), were negatively affected by livestock grazing. Increases 
in willow flycatcher numbers (various subspecies) have followed 
reduction, modification, or removal of cattle grazing. Taylor (1986) 
found a negative correlation between recent cattle grazing and 
abundance of numerous riparian birds, including the Great Basin willow 
flycatcher (E. t. adastus). In an area ungrazed since 1940, his bird 
counts were five to seven times higher than comparable plots where 
grazing was terminated in 1980. Taylor and Littlefield (1986) found 
higher numbers of Great Basin willow flycatchers correlated with 
minimal or nonexistent livestock grazing. Klebenow and Oakleaf (1984) 
listed the Great Basin willow flycatcher among bird species that 
declined from abundant to absent in riparian habitats degraded in part 
by overgrazing. Schlorff reported willow flycatchers returning to Modoc 
County, California, several years after removal of livestock grazing 
(pers. comm. cited in Valentine et al. 1988). Knopf et al. (1988) found 
that, during the summer, Great Basin willow flycatchers were present on 
winter-grazed pastures, but were virtually absent from summer-grazed 
pastures.
    The Service believes that documentation of livestock impacts on 
other willow flycatcher subspecies is relevant to E. t. extimus, 
because linear riparian habitats in the arid range of E. t. extimus are 
especially vulnerable to fragmentation and destruction by livestock. As 
shady, cool, wet areas providing abundant forage, they are 
disproportionately preferred by livestock over the surrounding xeric 
uplands (Ames 1977, Valentine et al. 1988, A. Johnson 1989). Harris et 
al. (1987) believed that termination of grazing along portions of the 
South Fork of the Kern River in California was responsible for 
increases in riparian vegetation and, consequently, nesting E. t. 
extimus. Suckling et al. (1992) noted that most of the areas still 
known to support E. t. extimus have low or nonexistent levels of 
livestock grazing. More recent surveys (Muiznieks et al. 1994) have 
found E. t. extimus in areas with livestock grazing; however, these 
occur in widely dispersed, small groups whose nesting success is 
largely unknown, and where livestock grazing intensity and seasonality 
are also unknown.
    Another likely factor in the loss and modification of southwestern 
willow flycatcher habitat is invasion by the exotic tamarisk. Tamarisk 
(also called saltcedar) was introduced into western North America from 
the Middle East in the late 1800's as an ornamental windbreak and for 
erosion control. It has spread rapidly along southwestern watercourses, 
typically at the expense of native riparian vegetation, especially 
cottonwood/willow communities. Although tamarisk is present in nearly 
every southwestern riparian community, its dominance varies. It has 
replaced some communities entirely, but occurs at a low frequency in 
others.
    The spread and persistence of tamarisk has resulted in significant 
changes in riparian plant communities. In monotypic tamarisk stands, 
the most striking change is the loss of community structure. The 
multilayered community of herbaceous understory, small shrubs, middle-
layer willows, and overstory deciduous trees is often replaced by one 
monotonous layer. Plant species diversity has declined in many areas, 
and relative species abundance has shifted in others. Other effects 
include changes in percent cover, total biomass, fire cycles, thermal 
regimes, and perhaps insect fauna (Kerpez and Smith 1987, Carothers and 
Brown 1991, Rosenberg et al. 1991, Busch and Smith 1993).
    Disturbance regimes imposed by man (e.g., grazing, water diversion, 
flood control, woodcutting, and vegetation clearing) have facilitated 
the spread of tamarisk (Behle and Higgins 1959, Kerpez and Smith 1987, 
Hunter et al. 1988, Rosenberg et al. 1991). Cattle find tamarisk 
unpalatable. However, they eat the shoots and seedlings of cottonwood 
and willow, acting as a selective agent to shift the relative abundance 
of these species (Kerpez and Smith 1987). Degradation and, in some 
cases, loss of native riparian vegetation lowered the water table and 
resulted in the loss of perennial flows in some streams. With its deep 
root system and adaptive reproductive strategy, tamarisk thrives or 
persists where surface flow has been reduced or lost. Further, tamarisk 
establishment often results in a self-perpetuating regime of periodic 
fires, which were uncommon in native riparian woodlands (Busch and 
Smith 1993).
    Manipulation of perennial rivers and streams has resulted in 
habitats that tend to allow tamarisk to outcompete native vegetation. 
Construction of dams created impoundments that destroyed native 
riparian communities. Dams also eliminated or changed flood regimes, 
which were essential in maintaining native riparian ecosystems. 
Changing (usually eliminating) flood regimes provided a competitive 
edge to tamarisk. In contrast to native phreatophytes, tamarisk does 
not need floods and is intolerant of submersion when young. Diversion 
of water caused the lowering of near-surface groundwater and reduced 
the relative success of native species in becoming established. 
Irrigation water containing high levels of dissolved salts also favors 
tamarisk, which is more tolerant of high salt levels than most native 
species (Kerpez and Smith 1987, Busch and Smith 1993).
    The rapid spread of tamarisk has coincided with the decline of the 
southwestern willow flycatcher. Although E. t. extimus has been 
documented nesting in tamarisk, it is not known whether, over the long 
term, reproductive success of southwestern willow flycatchers nesting 
in tamarisk has differed from the success of flycatchers nesting in 
native vegetation. Studies in Arizona have documented low breeding 
densities and low reproductive success for southwestern willow 
flycatchers nesting in tamarisk (Hunter et al. 1988, Muiznieks et al. 
1994). These data, coupled with a possible decrease in the arthropod 
prey base and thermal protection for nests provided by tamarisk, 
suggest that tamarisk may provide poor quality nesting habitat. 
However, more extensive comparative studies are needed to determine the 
overall impact on the southwestern willow flycatcher of the conversion 
of native broadleaf-dominated riparian habitat to tamarisk-dominated 
habitat.
    Other studies of riparian bird communities have documented changes 
in bird species diversity, corresponding with invasion by tamarisk.
    Conversion to tamarisk typically coincides with reduction or 
complete loss of bird species strongly associated with cottonwood-
willow habitats. These include the yellow-billed cuckoo (Coccyzus 
americanus), summer tanager (Piranga rubra), northern oriole (Icterus 
galbula), and the southwestern willow flycatcher (Hunter et al. 1987, 
Hunter et al. 1988, Rosenberg et al. 1991). While Brown and Trosset 
(1989) believed tamarisk may serve as an ``ecological equivalent'' to 
native vegetation, they noted that their study occurred where a 
tamarisk community became established where no native equivalent 
existed before.
    Some authors believe tamarisk may not provide the thermal 
protection that native broadleaf species do (Hunter et al. 1987, Hunter 
et al. 1988). This could be important at lower elevations in the 
Southwest, where extreme high temperatures are common during the bird's 
midsummer breeding season. It is [[Page 10709]] also possible that 
tamarisk affects E. t. extimus by altering the riparian insect fauna 
(Carothers and Brown 1991). Some sources also speculated that nests in 
tamarisk stands may be more easily located by brown-headed cowbirds 
(see cowbird discussion below). Hunter et al. (1987) reported the 
willow flycatcher as one of seven midsummer-breeding builders of open 
nests that were found in tamarisk at higher elevations but not lower 
elevations. Nesting E. t. extimus have been found in tamarisk at middle 
elevations (610-1200 m (2000-3500 feet)) (Hundertmark 1978, Hubbard 
1987, Hunter et al. 1987, Brown 1988, Sogge et al. 1993, Muiznieks et 
al. 1994). However, nest success in tamarisk at these elevations 
appears to be low (Sogge and Tibbitts 1992, Sogge et al. 1993, 
Muiznieks et al. 1994). The species is essentially absent from 
tamarisk-dominated habitats below 610 m (2000 feet). On the lower 
Colorado River (approximately 25 m (80 feet)) where tamarisk is widely 
dominant, the only territories found in recent decades were in relict 
stands dominated by willow, cottonwood, and other native vegetation 
(Muiznieks et al. 1994). Unitt (1987) speculated that at higher 
elevations and in the eastern portion of its range, some E. t. extimus 
populations may be adapting to tamarisk.
    Water developments also likely reduced and modified southwestern 
willow flycatcher habitat. The series of dams along most major 
southwestern rivers (Colorado, Gila, Salt, Verde, Rio Grande, Kern, San 
Diegito, and Mojave) have altered riparian habitats downstream of dams 
through hydrological changes, vegetational changes, and inundated 
habitats upstream. New habitat is sometimes created along the shoreline 
of reservoirs, but this habitat (often tamarisk) is often unstable 
because of fluctuating levels of regulated reservoirs (Grinnell 1914, 
Phillips et al. 1964, Rosenberg et al. 1991). Construction of Glen 
Canyon Dam on the Colorado River allowed establishment of a tamarisk 
riparian community downstream in the Grand Canyon, where a small 
population of E. t. extimus exists, with poor reproduction (Brown 1991, 
Sogge et al. 1993). However, Lake Powell, formed upstream of the dam, 
inundated what was apparently superior habitat, with E. t. extimus 
considered common (Behle and Higgins 1959).
    Diversion and channelization of natural watercourses are also 
likely to have reduced E. t. extimus habitat. Diversion results in 
diminished surface flows and increased salinity of residual flows. 
Consequent reductions and composition changes in riparian vegetation 
are likely. Channelization often alters stream banks and fluvial 
dynamics necessary to maintain native riparian vegetation.
    Suckling et al. (1992) suggested that logging in the upper 
watersheds of southwestern rivers may constitute another potential 
threat to the southwestern willow flycatcher. They stated that logging 
increases the likelihood of damaging floods in southwestern willow 
flycatcher nesting habitat.
    Finally, the willow flycatcher (all subspecies) is listed among 
neotropical migratory birds that may be impacted by alteration of 
wintering habitat, as through tropical deforestation (Finch 1991, 
Sherry and Holmes 1993).

Population Trends for Each State Are Discussed Briefly Below

    California. All three resident subspecies of the willow flycatcher 
(E. t. extimus, E. t. brewsteri, and E. t. adastus) were once 
considered widely distributed and common in California, wherever 
suitable habitat existed (Wheelock 1912, Willett 1912, Grinnell and 
Miller 1944). The historic range of E. t. extimus in California 
apparently included all lowland riparian areas of the southern third of 
the State. Unitt (1984, 1987) concluded that it was once fairly common 
in the Los Angeles basin, the San Bernardino/Riverside area, and San 
Diego County. Willett (1912, 1933) considered the bird to be a common 
breeder in coastal southern California. Nest and egg collections 
indicate the bird was a common breeder along the lower Colorado River 
near Yuma in 1902 (T. Huels, University of Arizona in litt., 
transcripts of H. Brown's field notes).
    All three willow flycatcher subspecies breeding in California have 
declined, with declines most critical in E. t. extimus, which remains 
only in small, disjunct nesting groups (Unitt 1984 and 1987, Gaines 
1988, Schlorff 1990, Service unpubl. data). Only two nesting groups 
have been stable or increasing in recent years. One is on private land 
where habitat impacts from livestock grazing have been virtually 
eliminated (Harris et al. 1987, Whitfield 1990). This group on the 
South Fork of the Kern River experienced numerical declines in 1991 and 
1992, but increases in nesting success were realized in 1992 and 1993, 
attributed to shaking (killing) or removing cowbird eggs or nestlings 
found in flycatcher nests, and trapping cowbirds (Whitfield and Laymon, 
Kern River Research Center, in litt. 1993). The other apparently stable 
nesting group is along the Santa Margarita River on Marine Corps Base 
Camp Pendleton, where cowbird numbers have also been reduced by 
trapping (Griffith and Griffith 1993). Approximately eight other 
nesting groups are known in southern California, all of which consisted 
of six or fewer nesting pairs in recent years (Unitt 1987, Schlorff 
1990, Service, unpubl. data). Using the most recent information for all 
areas, approximately 70 pairs and 8 single southwestern willow 
flycatchers are known to exist in California. Where information on 
population trends since the mid-1980's is available, most areas show 
declines. Three recent status reviews considered extirpation from 
California to be possible, even likely, in the foreseeable future 
(Garrett and Dunn 1981, Harris et al. 1986, Schlorff 1990). The State 
of California classifies the willow flycatcher as endangered 
[California Department of Fish and Game (CDFG) 1992].
    Arizona. Records indicate that the former range of the southwestern 
willow flycatcher in Arizona included portions of all major watersheds 
(Colorado, Salt, Verde, Gila, Santa Cruz, and San Pedro). Historical 
records exist from the Colorado River near Lee's Ferry and near the 
Little Colorado River confluence (Phillips, pers. comm., cited in Unitt 
1987), and along the Arizona-California border (Phillips 1948, Unitt 
1987), the Santa Cruz River near Tucson (Swarth 1914, Phillips 1948), 
the Verde River at Camp Verde (Phillips 1948), the Gila River at Fort 
Thomas (W.C. Hunter, pers. comm., cited in Unitt 1987), the White River 
at Whiteriver, the upper and lower San Pedro River (Willard 1912, 
Phillips 1948), and the Little Colorado River headwaters area (Phillips 
1948).
    The southwestern willow flycatcher has declined throughout Arizona. 
The subspecies was apparently abundant on the lower Colorado River in 
1902 (T. Huels in litt., transcripts of H. Brown's field notes), but 
only four to five territories were located in 1993 (Muiznieks et al. 
1994). Elsewhere in the State, E. t. extimus persists only in several 
small, widely scattered locations. In the Grand Canyon, several groups 
of nesting birds have fluctuated from a high of 11 singing males in 
1986 (Brown 1988) to two pairs and three single birds in 1992 (Sogge 
and Tibbitts 1992). Grand Canyon surveys in 1993 located 13 birds; six 
unpaired individuals, two pairs, and what appeared to be one male with 
two females. No nesting attempts were successful (Sogge et al. 1993). 
Although Brown (et al. 1987) noted E. t. extimus as nesting in Havasu 
Canyon, in 1993 none were located there and cowbirds were abundant 
(Sogge et al. 1993). A [[Page 10710]] location on the lower San Pedro 
River apparently supported relatively large numbers of E. t. extimus in 
the 1940's (G. Monson, private individual, in litt. 1993 and pers. 
comm. 1993), but only a single pair in 1978 and 1979, and none in 1986 
(Unitt 1987). Following habitat improvements at this locale, six to 
seven singing males were present in 1993, and a total of 11 singing 
males were located at two other locations on the lower San Pedro in 
1993 (Muiznieks et al. 1994).
    Historically occupied habitat on the upper San Pedro River is in 
the process of rehabilitation, but remains unoccupied by nesting E. t. 
extimus (Krueper and Corman 1988, D. Krueper unpubl. data). Two small 
groups at high elevations in the White Mountains, comprising 
approximately five singing males each, have remained relatively stable 
numerically from 1985 to 1993 (Muiznieks et al. 1994, Arizona Game and 
Fish Department (AGFD), unpubl. data). At a site on the Verde River in 
central Arizona where R. Ohmart (unpubl. data) observed four nesting 
pairs in 1992, one pair and one single male were present in 1993. The 
single nest produced only a cowbird young. Of 13 river reaches in 
Arizona studied by Hunter et al. (1987), nesting E. t. extimus were 
extirpated from eight, declining in two, and present in stable numbers 
in three.
    Statewide surveys in 1993 located between 42 and 56 territorial 
males, and all nest sites were considered vulnerable to habitat loss 
and cowbird parasitism (Muiznieks et al. 1994). Preliminary data from 
1994 surveys indicate that approximately 70 to 80 breeding pairs were 
found at a total of 12 locations in the State. This included the 
discovery of a group of flycatchers at one location consisting of 
approximately 15 breeding pairs. Brood parasitism by cowbirds was 
documented at at least six (50%) of those 12 sites. Brown-headed 
cowbirds were documented at all 12 breeding locations (Arizona Game and 
Fish Department, in prep.).
    Where information on population trends since the mid-1980's is 
available, most areas show declines and/or high rates of cowbird 
parasitism. In early 1993, catastrophic flooding on the Verde, Gila, 
and San Pedro Rivers temporarily damaged many sites inhabited since the 
mid-1980's, and much potential habitat. Unitt (1987) concluded that 
``Probably the steepest decline in the population levels of E. t. 
extimus has occurred in Arizona * * * E. t. extimus has been extirpated 
from much of the area from which it was originally described, the 
riparian woodlands of southern Arizona.'' The State of Arizona 
classifies the willow flycatcher as endangered (AGFD 1988).
    New Mexico. Bailey (1928) classified breeding willow flycatchers in 
New Mexico as E. t. brewsteri, according to Oberholser's (1918) 
taxonomy of that time. Because of few records at that time, she 
believed that either the bird was rare or was overlooked by most 
observers and collectors. More recently, Hubbard (1987) reviewed and 
summarized the flycatcher's status in New Mexico. He classified 
breeding birds in the State as E. t. extimus and reported breeding 
locations that were generally confined to the regions west of the Rio 
Grande, with records from the Rio Grande, Chama, Zuni, San Francisco, 
and Gila drainages (See also Hubbard 1982). However, he provisionally 
assigned all willow flycatchers nesting in New Mexico to E. t. extimus, 
noting records from the Pecos River and Penasco Creek in the southeast 
and from near Las Vegas in the northeast.
    Both Hubbard (1987) and Unitt (1987) believed that the overall 
range of E. t. extimus had not been reduced in New Mexico, but that 
habitat and numbers had declined. Unitt (1987) believed the majority of 
all remaining nesting birds may occur in New Mexico. Areas with 19 and 
53 singing flycatchers, not distinguished as nesting or migrants, were 
found on the upper Gila River (Montgomery et al. 1985, cited in 
Suckling et al. 1992). Preliminary data from 1994 surveys indicate that 
this breeding group is still present. However, the breeding status of 
flycatchers and trend over time have not been determined (S.O. 
Williams, New Mexico Department of Game and Fish--pers. comm.)
    Hubbard (1987) noted that data were lacking for trends of most 
nesting areas. However, where data were available, they indicated loss 
of a group of 15 breeding pairs by the rising waters of Elephant Butte 
Reservoir. The willow flycatcher was considered fairly common in this 
area on the middle Rio Grande in the late 1970's (Hundertmark 1978). 
Hubbard hypothesized that some of these birds could have moved 
upstream, to new shoreline habitat created by the impoundment. Between 
1987 and 1990, bird surveys along the Rio Grande Valley State Park in 
Albuquerque found a single singing willow flycatcher during the 
breeding season (Hoffman 1990). Current trends in New Mexico are not 
being extensively monitored. However, in 1992, 71 transects along the 
Rio Grande were surveyed for breeding birds, but not specifically 
targeting willow flycatcher habitat. A single willow flycatcher was 
located near Espanola (Leal, Meyer and Thompson, unpubl. data). In 
1993, surveys of 52 locations found 31 pairs or singing males at 15 of 
those locations (S.O. Williams III, New Mexico Department of Game and 
Fish (NMDGF), in litt. 1993). Hubbard (1987) estimated that the State 
population may total 100 pairs; that estimate has not been revised. 
Hubbard (1987) found that ``the conclusion is virtually inescapable * * 
* a decrease has occurred in the population of breeding willow 
flycatchers in New Mexico over historic time,'' resulting from habitat 
loss. The State of New Mexico classifies the willow flycatcher as 
endangered (NMDGF 1988).
    Texas. The eastern limit of the southwestern willow flycatcher's 
breeding range is in western Texas (Unitt 1987). Collections have been 
made at Fort Hancock on the Rio Grande (Phillips 1948), in the 
Guadalupe Mountains (Phillips, pers. comm., cited in Unitt 1987), the 
Davis Mountains (Oberholser 1974), and from unspecified locales in 
Brewster County (Wolfe 1956). Wauer (1973 and 1985) considered E. t. 
extimus a rare summer resident in Big Bend National Park. Data are 
lacking on current population levels and trends in Texas. Loss and 
modification of habitat may have reduced populations on the Rio Grande 
and Pecos Rivers.
    Utah. The north-central limit of breeding southwestern willow 
flycatchers is in southern Utah. Behle (1985) and Unitt (1987) believed 
a clinal gradation between E. t. extimus and E. t. adastus existed, but 
Browning (1993) disagreed, identifying a range boundary at 
approximately the 38th north parallel. Southern Utah is characterized 
by extreme topographic relief. In this region, subspecific separation 
may be a function of elevation, with E. t. extimus at lower elevations 
(e.g., Virgin and Colorado Rivers) and E. t. adastus higher (e.g., 
Sevier River, wet meadows of mountains and high plateaus). Records that 
are likely to represent E. t. extimus are from the Virgin River 
(Phillips 1948, Wauer and Carter 1965, Whitmore 1975), Kanab Creek, and 
along the San Juan and Colorado Rivers (Behle et al. 1958, cited in 
Unitt 1987; Behle and Higgins 1959, Behle 1985; see also Browning 
1993). Other reports document the subspecies being present along the 
Virgin, Colorado, San Juan, and perhaps Paria Rivers (BLM, unpubl. 
data). Although Behle believed E. t. extimus was always rare in 
southern Utah overall (pers. comm. cited in Unitt 1987), he considered 
it a locally common breeding resident where habitat existed along the 
Colorado River [[Page 10711]] and its tributaries in southeastern Utah 
(Behle and Higgins 1959).
    Few data are available on population trends in southern Utah. 
However, loss and modification of habitat is likely to have reduced 
populations on the Virgin, Colorado, and San Juan Rivers. These losses 
have been due to suburban expansion and habitat changes along the 
Virgin River, inundation by Lake Powell on the Colorado and San Juan 
Rivers, and encroachment of tamarisk throughout the region (Unitt 1987, 
BLM unpublished data).
    Nevada. Unitt (1987) reported only three records for Nevada, all 
made before 1962. Unitt (1987), Hubbard (1987), and Browning (1993) all 
considered southern Nevada (approximately south of 38 deg. north 
parallel) to be within the range of E. t. extimus. However, no recent 
data are available on population levels or trends. Habitat may remain 
along the lower Virgin River and at the inflow of the Virgin River into 
Lake Mead. However, loss and modification of habitat is likely to have 
reduced populations on the Virgin and Colorado Rivers.
    Colorado. Whether or not the southwestern willow flycatcher breeds 
in Colorado is unclear. Hubbard (1987) believed the subspecies ranged 
into extreme southwestern Colorado, Browning (1993) was noncommittal, 
and Unitt (1987) tentatively used the New Mexico-Colorado border as the 
boundary between E. t. extimus and E. t. adastus. Several specimens 
taken in late summer have been identified as E. t. extimus, but nesting 
was not confirmed (Bailey and Niedrach 1965). Phillips (1948) cautioned 
that willow flycatchers in this region displayed considerable 
individual variation and may represent intergrades between E. t. 
extimus and E. t. adastus. No recent data are available on occurrence, 
population levels, or trends in this area.
    Mexico. Six specimens from Baja California del Norte and two from 
Sonora were discussed by Unitt (1987). He and Phillips (pers. comm., 
cited in Unitt 1987) believed E. t. extimus was not common in 
northwestern Mexico. Wilbur (1987) was skeptical of its presence as a 
breeder in Baja California. In the more general treatments of field 
guides, the willow flycatcher is described as breeding in extreme 
northwestern Mexico, including northern Baja California del Norte 
(Blake 1953, Peterson 1973). No recent data are available on current 
population levels or trends.
    Using the most recent censuses and estimates for all areas, the 
estimated total of all southwestern willow flycatchers is approximately 
300 to 500 nesting pairs. Unitt (1987) believed the total was ``well 
under'' 1000 pairs, more likely 500. The regional estimates and 
information on which these total estimates are based generally date 
from the late 1980's to 1993 (e.g., Hubbard 1987, T. Johnson 1989). 
Virtually all nesting groups monitored since that time have continued 
to decline (Whitfield 1990, Brown 1991, Sogge et al. 1993, Whitfield 
and Laymon, unpubl. data).

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The Service is unaware of threats resulting from overutilization.

C. Disease or Predation

    The Service is unaware of any disease that constitutes a 
significant threat to E. t. extimus. Boland et al. (1989) found only 
one case of larval parasites in willow flycatcher nestlings in 
California.
    Predation of southwestern willow flycatchers may constitute a 
significant threat and may be increasing with habitat fragmentation. 
Where E. t. extimus has been extirpated in the lower Colorado River 
valley, Rosenberg et al. (1991) found increases in the great-tailed 
grackle (Quiscalus mexicanus), which preys on the eggs and young of 
other birds (Bent 1965). Whitfield (1990) found predation on E. t. 
extimus nests to be significant. Predation increased with decreasing 
distance from nests to thicket edges, suggesting that habitat 
fragmentation may increase the threat of predation.

D. The Inadequacy of Existing Regulatory Mechanisms

    The Migratory Bird Treaty Act (MBTA)(16 U.S.C. Sec. 703-712) is the 
only current Federal protection provided for the southwestern willow 
flycatcher. The MBTA prohibits ``take'' of any migratory bird, which is 
defined as: ``* * * to pursue, hunt, shoot, wound, kill, trap, capture, 
or collect, or attempt to pursue, hunt, shoot, wound, kill, trap, 
capture, or collect * * *'' However, unlike the Act, there are no 
provisions in the MBTA preventing habitat destruction unless direct 
mortality or destruction of active nests occurs.
    The majority of the southwestern willow flycatcher's range lies 
within California, Arizona, and New Mexico (Phillips 1948, Hubbard 
1987, Unitt 1987). All of those States classify the willow flycatcher 
as endangered (AGFD 1988, NMDGF 1988, CDFG 1992). The State listings in 
New Mexico and Arizona do not convey habitat protection or protection 
of individuals beyond existing regulations on capture, handling, 
transportation, and take of native wildlife. The California Endangered 
Species Act (CESA) prohibits unpermitted possession, purchase, sale, or 
take of listed species. However, the CESA definition of take does not 
include harm, which under the Act can include destruction of habitat 
that actually kills or injures wildlife by significantly impairing 
essential behavioral patterns (50 CFR 17.3). However, CESA requires 
consultation between the CDFG and other State agencies to ensure that 
activities of State agencies will not jeopardize the continued 
existence of State-listed species (E. Toffoli, State of California, in 
litt. 1992). The Service believes that this and other regulatory 
mechanisms are inadequate to ensure the continued existence of the 
southwestern willow flycatcher.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The riparian habitat of the southwestern willow flycatcher has 
always been rare and has become more so. Its habitat rarity and small, 
isolated populations make the remaining E. t. extimus increasingly 
susceptible to local extirpation through stochastic events such as 
floods, fire, brood parasitism, predation, depredation, and land 
development. In early 1993, catastrophic floods in southern California 
and Arizona impacted much of the remaining occupied or potential 
breeding habitat. Historically, these floods have always destroyed 
habitat but were also important events in regenerating cottonwood-
willow communities. However, with little southwestern willow flycatcher 
habitat remaining, widespread events like those of 1993 could destroy 
virtually all remaining habitat throughout all or a significant portion 
of the subspecies' range. Further, regeneration with natural vegetation 
after floods may be inhibited if the area is subjected to overgrazing 
by domestic livestock.
    The disjunct nature of habitats and small breeding populations 
impede the flow of genetic material and reduce the chance of 
demographic rescue from migration from adjacent populations. The 
resulting constraints on the gene pool intensify the external threats 
to the species.
    Brood parasitism by the brown-headed cowbird also threatens the 
southwestern willow flycatcher. Cowbirds lay their eggs in the nests of 
other, usually smaller, songbirds. The cowbird often removes a number 
of the host's eggs and replaces them with an equal number of cowbird 
eggs. The host [[Page 10712]] species then incubates the cowbird eggs, 
which typically hatch prior to the host's own eggs. Cowbird eggs 
require a relatively short incubation period of 10 to 12 days. Thus, 
the young cowbirds have several advantages over the host's young; they 
hatch earlier, they are larger, and they are also more aggressive than 
the host's young. Cowbird nestlings typically outcompete those of the 
host species for parental care, and, as a result, the host species' own 
reproduction is reduced or eliminated (Bent 1965, McGeen 1972, Mayfield 
1977a, Harrison 1979, Brittingham and Temple 1983).
    The brown-headed cowbird commonly preys on insects stirred up by 
grazing ungulates, and was originally restricted to the Great Plains, 
where it was strongly associated with American bison (Bison bison). As 
North America was settled, cowbirds became associated with livestock 
and human agriculture because of the food sources they provided (Bent 
1965, Flett and Sanders 1987, Valentine et al. 1988). The expansion of 
agriculture, livestock grazing, and wide scale human activities in 
general caused opening and fragmenting of forest and woodland habitats. 
Habitat fragmentation and agriculture are strongly correlated with 
increased rates of brood parasitism by brown-headed cowbirds (Rothstein 
et al. 1980, Brittingham and Temple 1983, Airola 1986, Robinson et al. 
1993). Some species are likely to have adapted to parasitism over time, 
particularly prairie nesters in the original range of the cowbird. 
However, the cowbird's rapid expansion now brings it into contact with 
forest and woodland species not adapted to deal with brood parasitism, 
significantly impacting those species (Hill 1976, Mayfield 1977a, 
Robinson et al. 1993).
    The brown-headed cowbird was apparently an uncommon bird within the 
range of E. t. extimus, until the late 1800's. Since then, the species 
has greatly expanded in numbers and distribution throughout the region 
(Laymon 1987, Rothstein in prep.). Increases in cowbirds in the San 
Bernardino Valley between 1918 and 1928 caused Hanna (1928) 
``considerable alarm.'' Although Friedmann et al. (1977) reported 
relatively low rates of parasitism of willow flycatchers in the western 
United States, this was apparently owing to their data (egg sets) being 
collected prior to the major incursions of cowbirds into Pacific coast 
riparian habitats (L. Kiff, Western Foundation for Vertebrate Zoology, 
in litt. 1993). Brood parasitism of several subspecies of the willow 
flycatcher, including E. t. extimus, by brown-headed cowbirds is well 
documented (Hanna 1928, Rowley 1930, Willett 1933, Hicks 1934, King 
1954, Holcomb 1972, Friedmann et al. 1977, Garret and Dunn 1981, Harris 
et al. 1987, Brown 1988, 1991, Sedgewick and Knopf 1988, Whitfield 
1990, Harris 1991, Sogge et al. 1993, Muiznieks et al. 1994).
    The increases in cowbirds in the Southwest and parasitism of E. t. 
extimus and other birds are generally attributed to the following 
scenario: The introduction of modern human settlements, livestock 
grazing, and other agricultural developments resulted in habitat 
fragmentation. Simultaneously, livestock grazing and other agricultural 
developments served as vectors for cowbirds by providing feeding areas 
near host species' nesting habitats (Hanna 1928, Gaines 1974, Mayfield 
1977a). Cowbirds may travel almost 7 kilometers (4.2 miles) from 
feeding sites where livestock congregate to areas where host species 
are parasitized (Rothstein et al. 1984). These factors increased both 
the vulnerability of E. t. extimus and the likelihood of encounters 
with cowbirds. Finally, the high edge-to-interior ratio of linear 
riparian habitats like those used by E. t. extimus renders birds 
nesting there particularly vulnerable to parasitism (Airola 1986, 
Laymon 1987, Harris 1991). Linear riparian habitats are also especially 
vulnerable to fragmentation by grazing, which further increases both 
the edge-to-interior ratio and the threat of parasitism.
    The effects of parasitism by brown-headed cowbirds on willow 
flycatchers include reducing nest success rate and egg-to-fledging 
rate, and delaying successful fledging (because of renesting attempts) 
(Harris 1991). A common response to parasitism is abandonment of the 
nest (Holcomb 1972). Willow flycatchers may also respond to parasitism 
by ejecting cowbird eggs, by burying them with nesting material and 
renesting on top of them, or by renesting in another nest (Harris et 
al. 1991). However, the success rate of renesting is often reduced, 
because these attempts produce fledglings several weeks later than 
normal, which may not allow them adequate time to prepare for migration 
(Harris 1991). Renesting also usually consists of smaller clutches, 
further reducing overall reproductive potential (Holcomb 1974).
    McCabe (1991) downplayed the significance of cowbird parasitism as 
a threat to any species except Kirtland's warbler (Dendroica 
kirtlandii). McCabe's monograph focussed on the combined ``Traill's 
flycatcher'' superspecies, comprised of E. t. traillii and E. alnorum 
in marshy habitats in the upper Midwest, where parasitism rates ranged 
from 3 percent to 19 percent. However, perhaps reflecting his regional 
perspective, he characterized the high parasitism rates on willow 
flycatchers reported by Trautman (1940, cited in McCabe 1991) and 
Sedgwick and Knopf (1988) as aberrant (56 percent and 41 percent, 
respectively). McCabe considered the high rates the result of the ``* * 
* linear configuration of the habitat * * * [c]owbirds lay eggs in 
songbird nests closest to cover edge.'' The vast majority of 
southwestern willow flycatcher habitat is very linear and may 
experience higher rates of parasitism than other willow flycatcher 
subspecies.
    Brittingham and Temple (1983) considered ``high'' parasitism rates 
(percent of nests parasitized) to be 24 percent, with some as high as 
72 percent. Mayfield (1977a) thought a species (or population) might be 
able to survive a 24 percent parasitism rate, but that losses much 
higher than that ``would be alarming.'' Parasitism rates of 72 percent 
to 83 percent on Kirtland's warbler (Mayfield 1977b) resulted in a 
precipitous population decline. Where parasitism rates are known for E. 
t. extimus, they are comparable to rates for Kirtland's warbler and are 
capable of causing similar declines. In California, parasitism rates 
ranged from 50 percent to 80 percent between 1987 and 1992, when an 
estimated population size decreased from 44 to 28 nesting pairs 
(Whitfield 1990, Harris et al. 1991, Whitfield and Laymon, unpubl. 
data). These parasitism rates were considered minimum measures, because 
several nests were abandoned each year due to unknown causes, which 
could have been parasitism. Brown (1988) reported an average 50 percent 
parasitism rate in the Grand Canyon between 1982 and 1987. Although his 
estimated population increased from two pairs to 11 during that period, 
it has since decreased back as low as two nesting pairs (Brown 1991, 
Sogge and Tibbitts 1992). In 1993, parasitism reached 100 percent in 
the Grand Canyon, and no E. t. extimus were fledged (Sogge et al. 
1993). Harris et al. (1991) believed that the parasitism rates observed 
on the Kern River in 1987 (68 percent of all nests, 88 percent of all 
nest territories) were high enough to prevent E. t. extimus from 
recolonizing lowland riparian habitat, even if it were restored.
    Rothstein et al. (1980), Stafford and Valentine (1985), and Harris 
(1991) believed parasitism may be correlated with elevation, being more 
severe at lower elevations. Coupled with greater loss of lowland 
(desert) riparian habitat, [[Page 10713]] the effects of habitat loss 
and parasitism are compounded. However, cowbirds now appear to be 
increasing at higher elevations (Hanka 1985).
    In addition to causing habitat degradation and facilitating brood 
parasitism, livestock grazing in and near riparian areas may also 
threaten E. t. extimus through direct mortality. Livestock in riparian 
habitats sometimes make physical contact with nests or supporting 
branches, resulting in destruction of nests and spillage of eggs or 
nestlings. All known documentation of this threat involves E. t. 
brewsteri, perhaps because virtually all known remaining populations of 
E. t. extimus are in ungrazed habitats (Serena 1982, Harris et al. 
1987, Whitfield and Laymon, unpubl. data). Valentine et al. (1988) 
studied willow flycatchers in California from 1983 through 1987, when 
11 of their 20 recorded nesting attempts failed. They found that 
``Prior to reduction of grazing intensity in 1987, livestock accounted 
for 36 percent of the failed nests or 20 percent of all nesting 
attempts. In addition, livestock destroyed four successful nests 
shortly after the young had fledged.'' Stafford and Valentine (1985) 
reported that three of eight (37.5 percent) willow flycatcher nests in 
their study site were probably destroyed by cattle. Flett and Sanders 
(1987) documented no nest upsets due to livestock but noted the 
vulnerability of nests to upset, due to their placement low in willow 
clumps (see also Serena 1982). Livestock grazing may affect E. t. 
extimus similarly.
    The southwestern willow flycatcher's preference for, and former 
abundance in, floodplain areas that are now largely agricultural may 
indicate a potential threat from pesticides. Where flycatcher 
populations remain, they are sometimes in proximity to agricultural 
areas, with the associated pesticides and herbicides. Without 
appropriate precautions, these agents may potentially affect the 
southwestern willow flycatcher through direct toxicity or effects on 
their insect food base. No quantitative data on this potential threat 
are known at this time.
    Recreation that is focused on riparian areas, particularly during 
warm summer breeding months, may also constitute a threat to E. t. 
extimus. Taylor (1986) found a possible correlation between 
recreational activities and decreased riparian bird abundance. 
Blakesley and Reese (1988) reported the willow flycatcher (probably E. 
t. adastus) as one of seven species negatively associated with 
campgrounds in riparian areas in northern Utah. It is unknown whether 
these possible effects involve impacts to habitat or disturbance of 
nesting birds.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by this species in determining to make this rule 
final. Based on this evaluation, the preferred action is to list the 
southwestern willow flycatcher as endangered. A decision regarding 
designation of critical habitat for this species is being deferred, and 
a final decision regarding the designation will be made by July 23, 
1995. Critical habitat for this species is not now determinable.

Critical Habitat

    Critical Habitat is defined in section 3 of the Act as (i) the 
specific areas within the area occupied by a species, at the time it is 
listed in accordance with the Act, on which are found those physical or 
biological features (I) essential to the conservation of the species 
and (II) that may require special management considerations or 
protection and; (ii) specific areas outside the geographical area 
occupied by a species at the time it is listed, upon a determination 
that such areas are essential for the conservation of the species. 
``Conservation'' means the use of all methods and procedures needed to 
bring the species to a point at which listing under the Act is no 
longer necessary.
    Section 4(a)(3) of the Act and implementing regulations (50 CFR 
424.12) require that, to the maximum extent prudent and determinable, 
the Secretary designate critical habitat at the time a species is 
determined to be endangered or threatened. Critical habitat was 
proposed to be designated for the flycatcher at the time it was 
proposed for listing as endangered to encompass approximately 640 miles 
(1000 km) of riparian zones in the States of California, Arizona, and 
New Mexico.
    After reviewing comments submitted during the public comment period 
the Service is deferring the designation of critical habitat for this 
endangered species. The Service received numerous comments on the 
proposed rule, including many recommendations for additions and 
deletions to proposed critical habitat. The Service is reviewing these 
comments as well as survey data collected in 1994. These sources 
included more complete information on the primary constituent elements 
of flycatcher habitat and on the distribution of that habitat across 
the bird's range. Substantial disagreement has also been found among 
scientists knowledgeable about the species regarding the proposed 
designations. Further, written comments submitted by State agencies 
recommended substantial changes in proposed critical habitat areas.
    The Service is presently reconsidering the prudence of critical 
habitat designation for this species, the need for special management 
considerations or protection of habitat within the species' range, and 
the proper boundaries of any areas that might be designated as critical 
habitat. Issues raised in public comments, new information, and the 
lack of the economic information necessary to perform the required 
economic analysis cause the Service to conclude that critical habitat 
is not now determinable and to invoke an extension until July 23, 1995, 
pursuant to 16 U.S.C. Sec. 1533(b)(6)(C) for reaching a final decision 
on the proposal of critical habitat for the flycatcher. The Service has 
determined that this is in compliance with provisions of 50 CFR 
424.12(a) and Sec. 424.17, regarding delaying final rules on proposed 
critical habitat designations, and with provisions for addressing State 
agencies that disagree in whole or part with a proposed rule (50 CFR 
424.18(c)). In order to assist in its deliberation, the Service is 
reopening comment on the proposal to designate critical habitat for a 
period of 60 days. Comments are particularly sought on the following 
topics:
    1. The need for special management of areas within the range of the 
flycatcher, including those proposed as critical habitat as well as 
other areas,
    2. The net benefit to the flycatcher in addition to the protection 
provided by its listing as endangered likely to accrue from a 
designation of critical habitat, and
    3. Any indication that areas should be added to or excluded from 
those proposed for designation.
    Comments already received that address the above topics will be 
considered in reaching a final decision regarding critical habitat 
designation, and need not be resubmitted.

Available Conservation Measures
    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing encourages and results in 
conservation actions by Federal, State, and local agencies, private 
organizations, and individuals. The Act provides for possible land 
acquisition and cooperation with the States and requires that recovery 
actions be carried out for all listed species. The protection required 
of Federal agencies [[Page 10714]] and the prohibitions against taking 
and harm are discussed, in part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
Part 402. Section 7(a)(4) requires Federal agencies to confer 
informally with the Service on any action that is likely to jeopardize 
the continued existence of a proposed species or result in destruction 
or adverse modification of proposed critical habitat. If a species is 
listed subsequently, Section 7(a)(2) requires Federal agencies to 
ensure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of such a species or 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into consultation with the Service.
    No conservation plans or habitat restoration projects specific to 
the southwestern willow flycatcher exist on lands managed by the U.S. 
Forest Service (USFS), BLM, U.S. Bureau of Reclamation (Reclamation), 
Indian Nations, State agencies, or the Service. The USFS and BLM have 
focussed some attention on modifying livestock grazing practices in 
recent years, particularly as they affect riparian ecosystems. As 
mitigation for other projects impacting riparian habitats, Reclamation 
is engaged in riparian habitat restoration projects in several areas in 
the range of E. t. extimus, including some historical nesting 
locations. The BLM currently manages approximately 40 miles of the 
upper San Pedro River in Arizona (including historic nest sites), as a 
Riparian National Conservation Area. Riparian habitat rehabilitation is 
also underway at several National Wildlife Refuges in the breeding 
range of E. t. extimus, which are managed by the Service. The Nature 
Conservancy manages one of the largest remaining flycatcher 
populations, as well as several other areas with high recovery 
potential. The U.S. Marines have maintained a cowbird control program 
near the Santa Margarita River to benefit the least Bell's vireo. This 
program has benefitted nesting southwestern willow flycatchers there. 
Grand Canyon National Park has instituted a seasonal recreation closure 
at the remaining site with nesting willow flycatchers in the Grand 
Canyon, and has begun a cowbird monitoring program.
    The Act and implementing regulations found at 50 CFR 17.21 set 
forth a series of general prohibitions and exceptions that apply to all 
endangered wildlife. These prohibitions, in part, make it illegal for 
any person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, or 
collect; or to attempt any of these), import or export, ship in 
interstate commerce in the course of commercial activity, or sell or 
offer for sale in interstate or foreign commerce any listed species. It 
also is illegal to possess, sell, deliver, carry, transport, or ship 
any such wildlife that has been taken illegally. Certain exceptions 
apply to agents of the Service and State conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered wildlife species under certain circumstances. 
Regulations governing permits are at 50 CFR 17.22 and 17.23. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, and/or for incidental take in 
connection with otherwise lawful activities.
    It is the policy of the Service (59 FR 34272) to identify to the 
maximum extent practicable at the time a species is listed those 
activities that would or would not constitute a violation of section 9 
of the Act. The intent of this policy is to increase public awareness 
of the effect of a listing on proposed and ongoing activities within a 
species' range. The Service believes that, based on the best available 
information, the following are examples of actions that will not result 
in a violation of section 9:
    (1) Dispersed recreational activities near willow flycatcher 
breeding areas that do not disrupt normal flycatcher breeding 
activities and behavior, attract avian and mammalian predators, nor 
result in the trampling or destruction of riparian breeding habitat;
    (2) Federally-approved projects that involve activities such as 
discharge of fill material, draining, ditching, tiling, pond 
construction, stream channelization or diversion, or diversion or 
alteration of surface or ground water flow into or out of the wetland 
(i.e., due to roads, impoundments, discharge pipes, stormwater 
detention basins, etc.)--when such activity is conducted in accordance 
with any reasonable and prudent measures given by the Service in 
accordance with section 7 of the Act; and
    (3) Livestock grazing that does not attract the brood parasitic 
brown-headed cowbird or result in the destruction of riparian habitat 
or the disturbance of breeding flycatchers.
    Activities that the Service believes could potentially harm the 
southwestern willow flycatcher and result in ``take,'' include, but are 
not limited to:
    (1) Unauthorized handling or collecting of the species;
    (2) Destruction/alteration of the species' habitat by discharge of 
fill material, draining, ditching, tiling, pond construction, stream 
channelization or diversion, or diversion or alteration of surface or 
ground water flow into or out of the wetland (i.e., due to roads, 
impoundments, discharge pipes, stormwater detention basins, etc.);
    (3) Livestock grazing that results in direct or indirect 
destruction of riparian habitat;
    (4) Activities such as continued presence of cattle and 
fragmentation of flycatcher habitat that facilitate brood parasitism by 
the brown-headed cowbird; and
    (5) Pesticide applications in violation of label restrictions.
    Questions as to whether specific activities will constitute a 
violation of section 9 should be directed to Sam F. Spiller or Robert 
M. Marshall at the Service's Ecological Services State Office, 2321 
West Royal Palm Road, Suite 103, Phoenix, Arizona 85021 (Telephone 602/
640-2720)

National Environmental Policy Act

    The Fish and Wildlife Service has determined that an Environmental 
Assessment and Environmental Impact Statements, as defined under the 
authority of the National Environmental Policy Act of 1969, need not be 
prepared in connection with regulations adopted pursuant to Section 
4(a) of the Act. A notice outlining the Service's reasons for this 
determination was published in the Federal Register on October 25, 1983 
(48 FR 49244).

References Cited

    A complete list of all references cited herein, as well as others, 
is available upon request from the Supervisor, Ecological Services 
State Office in Arizona (see ADDRESSES above).

Author

    The primary author of this rule is Robert M. Marshall, Ecological 
Services State Office in Arizona (see ADDRESSES above).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
record keeping requirements, and Transportation. [[Page 10715]] 

Regulation Promulgation

    Accordingly, part 17, subchapter B of chapter I, title 50 of the 
Code of Federal Regulations, is amended as set forth below:

PART 17--[AMENDED]

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

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under Birds, to the List of Endangered and 
Threatened Wildlife to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                      Species                                                  Vertebrate population                                                    
---------------------------------------------------      Historic range         where endangered or      Status    When listed    Critical     Special  
       Common name             Scientific name                                       threatened                                   habitat       rules   
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
          Birds                                                                                                                                         
                                                                                                                                                        
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
Flycatcher, southwestern  Empidonax traillii,       U.S.A. (AZ, CA, CO, NM,   Entire.................  E                   577           NA           NA
 willow.                   extimus.                  NV, TX, UT).                                                                                       
                                                                                                                                                        
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Dated: February 16, 1995.
Mollie H. Beattie,
Director, Fish and Wildlife Service.
[FR Doc. 95-4531 Filed 2-24-95; 8:45 am]
BILLING CODE 4310-55-P