Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-3_16-cv-06040/USCOURTS-cand-3_16-cv-06040-0/pdf.json

Nature of Suit Code: 899
Nature of Suit: Other Statutes - Administrative Procedure Act/Review or Appeal of Agency Decision
Cause of Action: 16:1538 Endangered Species Act

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United States District Court

For the Northern District of California

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IN THE UNITED STATES DISTRICT COURT

FOR THE NORTHERN DISTRICT OF CALIFORNIA

CENTER FOR BIOLOGICAL DIVERSITY,

ENVIRONMENTAL PROTECTION

INFORMATION CENTER, KLAMATHSISKIYOU WILDLANDS CENTER, and

SIERRA FOREST LEGACY,

Plaintiffs,

 v.

U.S. FISH & WILDLIFE SERVICE; RYAN

K. ZINKE, in his capacity as Secretary of the

Interior; and GREG SHEEHAN, in his

capacity as Principal Deputy Director of the

U.S. Fish & Wildlife Service,

Defendants. /

No. C 16-06040 WHA

ORDER RE CROSS-MOTIONS

FOR SUMMARY JUDGMENT

INTRODUCTION

In this action for declaratory and injunctive relief under the Endangered Species Act,

plaintiffs seek protection for the Pacific fisher. All parties have moved for summary judgment. 

For the reasons stated below, plaintiffs’ motion is GRANTED IN PART and defendants’ motions

are DENIED.

STATEMENT

The fisher is a medium-sized brown mammal in the weasel family found only in North

America. It has a long body with short legs and a long bushy tail. Fishers naturally populate in

low densities over large, non-overlapping ranges. 

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Beginning in the 1900’s, the Pacific fisher population — a “distinct population segment”

found in Washington, Oregon, and California — experienced significant decline due to

extensive logging and trapping. As such, the Pacific fisher has largely disappeared from its

historic range. Altogether, the Pacific fisher now exists in five populations — two small,

isolated native populations, the Northern California-Southwestern Oregon and Southern Sierra

Nevada populations, and three reintroduced populations, the Northern Sierra Nevada, Southern

Oregon Cascade, and Olympic Peninsula populations. Estimates for the Northern CaliforniaSouthwestern Oregon population size range from 258 to 4,018. Estimates for the Southern

Sierra Nevada population size range from 100 to 500 (AR 000684, 022630, 022641, 022647).

The Endangered Species Act aims to identify and to protect endangered and threatened

species and to “reverse the trend toward species extinction, whatever the cost.” Tenn. Valley

Auth. v. Hill, 437 U.S. 153, 184 (1978). To that end, the Secretary of the Interior is charged

with maintaining a list of “endangered” and “threatened” species. 16 U.S.C. § 1533. The

Secretary has delegated his authority to implement the Act, including the authority to make

listing decisions, to the United States Fish and Wildlife Service. See 50 C.F.R. § 402.01(b)

(2017).

An “endangered” species is “any species which is in danger of extinction throughout all

or a significant portion of its range.” 16 U.S.C. § 1532(6). A “threatened” species is any

species “which is likely to become an endangered species within the foreseeable future

throughout all or a significant portion of its range.” Id. § 1532(20). The term “species”

includes subspecies and “any distinct population segment of any species of vertebrate fish or

wildlife which interbreeds when mature.” Id. § 1532(16).

The Act permits interested persons to petition to add or remove species to the

endangered species lists. Id. § 1533(b)(3). The Service, as the Secretary’s delegee, must then

determine within 90 days of receiving a petition, “[t]o the maximum extent practicable,”

whether the petition is supported by “substantial scientific or commercial information.” Id. §

1533(b)(3)(A). If the Service finds that it is, it must “commence a review of the status of the

species concerned.” Ibid. The Service must make a finding on the status of the species within

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twelve months and publish its finding (the twelve-month finding). Id. § 1533(b)(3)(B). 

The twelve-month finding must make one of the following findings: the listing is (1)

not warranted; (2) warranted; or (3) warranted but precluded due to higher priorities. Id. §

1533(b)(3)(B). In making such a finding, the Service must assess five statutory factors “solely

on the basis of the best scientific and commercial data available”: (1) the present or threatened

destruction, modification, or curtailment of the species’ range; (2) overutilization for

commercial, recreational, scientific, or educational purposes; (3) disease or predation; (4) the

inadequacy of existing regulatory mechanisms; and (5) other natural or man-made factors

affecting the species’ continued existence. Id. §§ 1533(a)(1), (b)(1)(A).

Since 1990, petitions to protect the Pacific fisher have been filed three times. In 1991,

the Service concluded that listing the Pacific fisher as “endangered” was “not warranted.” In

1996, the Service again rejected a petition to list two fisher populations (including the Pacific

fisher population) as “threatened” due to lack of substantial information. In 2000, the Center

for Biological Diversity and other groups petitioned to list the Pacific fisher as endangered (AR

000680). 

In 2004, following the 2000 petition, the Service published a twelve-month finding that

the Pacific fisher listing was “warranted but precluded.” In 2010, plaintiffs sued the Service for

lack of expeditious progress on the Pacific fisher’s listing. In 2011, the parties dismissed the

action via stipulation as part of a larger multi-district litigation settlement agreement requiring

the Service to issue a proposed rule or “not warranted” finding by September 30, 2014 (ibid.). 

On October 7, 2014, the Service publicly proposed to list the Pacific fisher as

threatened. In its public statement, the Service concluded that the main threats or stressors to

the Pacific fisher were “habitat loss from wildfire and vegetation management; toxicants

(including anticoagulant rodenticides); and the cumulative and synergistic effects of these and

other stressors acting on small populations.” The Service further recognized “the isolation of

small populations and the higher risk of extinction due to stochastic events” as the “greatest

long-term risk.” The proposed rule acknowledged that the mere identification of stressors that

could impact a species negatively was insufficient to compel a listing. Rather, there must be

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“evidence that these stressors are operative threats that act on the species.” The Service then

called for public comment on the proposed rule and on its draft species report (AR 000677,

000684, 000691, 022360). 

On April 18, 2016, after the receipt of public comments, the Service reversed course and

withdrew the Pacific fisher’s proposed listing. The Service published its final species report,

which is a compilation of all of the best available science, in tandem with its final rule.

In the reversal, the Service stated that reconsideration of the information available prior

to the proposed listing, as well as all new information received thereafter, led it “to conclude

that the native populations will persist into the future . . . and that as a whole the [Pacific] fisher

does not meet the definition of an endangered or threatened species under the Act” (AR

000719).

The Service qualitatively reassessed the various stressors. For example, in discounting

wildfires as a threat, the reversal noted that new information suggested that wildfires have

beneficial consequences, such as creating new habitats for fishers and increasing prey

abundance. For small population size, the reversal noted that the separation of the two native

populations is longstanding and that despite their few numbers and isolation, the populations

have persisted over a long period of time. The reversal further observed that interchange

between the native Northern California-Southwestern Oregon population and two other

reintroduced populations “may be” beginning to occur. As for toxicant exposure, the reversal

emphasized what the Service characterized as a small number of confirmed deaths due to

toxicosis (AR 000720–21, 000726–29). 

Additionally, the Service quantitatively reassessed the stressors. The reversal stated that

a “key point” in the Service’s determination was that the best available information, in its view,

did not show that the stressors were “functioning as operative threats on the fisher’s habitat,

populations, or the proposed [distinct population segment] as a whole to the degree [the

Service] considered to be the case at the time of the proposed listing.” A 2015 conference call

memorandum noted that the decision to withdraw the proposed listing “hinged on the fact that

[the Service had] not yet seen threats acting to the point where there are declining population

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 The American Forest Resource Council, California Forestry Association, National Alliance of Forest Owners,

Oregon Forest Industries Council, and Washington Forest Protection Association’s unopposed motion to intervene as a

defendant was granted on January 24, 2017 (Dkt. No. 41). Because both defendants’ briefings largely overlap, the federaldefendant and intervenor-defendant’s motions are considered together for purposes of this order.

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trends since the time of the ‘warranted but precluded’ finding. Threats are evident but [the

Service hadn’t] seen the effects on population yet” (AR 000715, 126177).

Plaintiffs — members of the coalition that submitted the original petition to list the

Pacific fisher — now challenge the reversal. Plaintiffs argue that the reversal was arbitrary and

capricious as to these threats: (1) toxicants; (2) small population size; and (3) wildfires. 

Plaintiffs seek to set aside the Service’s reversal, to reinstate the Service’s proposed listing rule,

and an order requiring the Service to publish within ninety days a new rule based solely on “the

best scientific and commercial data available” (Dkt. No. 55 at 1).

Defendants respond that this is a matter of difference in interpretation of the scientific

evidence, and thus the Service’s interpretation and its ultimate reversal are entitled to deference. 

According to defendants, the reversal was anchored in new information elicited during the

comment period, which prompted the Service to reevaluate the identified stressors, individually

and cumulatively, that could impact the Pacific fisher population (Dkt. No. 57 at 8). In

reversing, defendants contend the Service both (1) “qualitatively analyz[ed] the scope and

severity of each identified stressor”; and (2) “analyzed whether or not identified stressors were

operating as threats at the population or range-wide level,” relying on “population trend data as

circumstantial evidence of stressors having a manifested impact” (id. at 12).1

 

This order follows a first round of full briefing and oral argument (Dkt. No. 71)

followed by a second round of supplemental briefing and further oral argument (Dkt. No. 79). 

The Court thanks counsel for both sides for their excellent advocacy. 

ANALYSIS

The Administrative Procedure Act governs the standard and scope of judicial review for

administrative decisions. Under the APA, the standard of review is whether the agency’s

decision was “arbitrary, capricious, an abuse of discretion or otherwise not in accordance with

the law.” Pac. Coast Fed. of Fishermen’s Ass’n v. Nat’l Marine Fisheries Serv., 265 F.3d 1028,

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1034 (9th Cir. 2001). In determining whether an agency’s decision was arbitrary and

capricious, a court must determine whether the agency articulated a “rational connection

between the facts found and the choice made.” An action will be deemed arbitrary and

capricious where the agency offers an explanation for an action “that runs counter to the

evidence before the agency, or is so implausible that it could not be ascribed to a difference in

view or the product of agency expertise.” Motors Vehicles Mfrs. Ass’n. v. State Farm Mutual

Auto. Ins. Co., 463 U.S. 29, 43 (1983). 

The APA requires “a substantial inquiry, a thorough, probing, in-depth review.” Native

Ecosystems Council v. U.S. Forest Serv., 418 F.3d 953, 960 (9th Cir. 2005). “While our

deference to the agency is significant, we may not defer to an agency decision that ‘is without

substantial basis in fact.’ ” Sierra Club v. U.S. EPA, 346 F.3d 955, 961 (9th Cir.2003) (quoting

FPC v. Fla. Power & Light Co., 404 U.S. 453, 463 (1972)).		“When an agency changes a policy

based on factual findings that contradict those on which the prior policy was based, an agency

must provide a ‘reasoned explanation . . . for disregarding facts and circumstances that underlay

or were engendered by the prior policy.’ ” Ctr. for Biological Diversity v. Zinke, 900 F.3d

1053, 1067–68 (9th Cir. 2018) (quoting FCC v. Fox Television Stations, Inc., 556 U.S. 502,

515–16 (2009)) (involving the Service’s reversal of a finding that listing was “warranted but

precluded”).

This order now applies these standards against the administrative record. 

1. ANTICOAGULANT RODENTICIDES AND OTHER TOXICANTS.

In the 2014 proposed listing, the Service viewed anticoagulant rodenticides and other

toxicants as “a newly identified threat because of the reported mortalities of fishers from

toxicants and a variety of sublethal effects” (AR 000690) — “mortalities” meaning direct

poisoning and “sublethal effects” meaning lethargy and other debilitations that render fishers

vulnerable to other direct causes of death (like predation). The main sources of anticoagulant

rodenticide exposure in California are illegal marijuana grows, where anticoagulant

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rodenticides are used to discourage herbivory and poison rats that might chew on young

marijuana plants (AR 022747). 

The proposed listing stated that the Service based its severity estimates regarding

toxicant exposure “on mortality rates alone, but [it] acknowledge[d] that th[ose] values likely

underrepresent the population-level effects when considering research conclusions regarding

sublethal levels of rodenticides and other toxicants in a wide variety of animal species” (AR

000690) (emphasis added). 

After the proposed listing, a new, subsequent study showed that the impact of toxicant

exposure had worsened. Plaintiffs thus argue that the Service’s 2016 reversal on toxicant

exposure was arbitrary and capricious. This order agrees, as now explained.

A. Studies on Toxicant Exposure.

After the proposed listing, a 2015 study by Gabriel and others showed a significant

increase in Pacific fisher mortality due to rodenticide poisoning, meaning the threat was

actually worse than previously thought. The authors explicitly warned of “an increase of this

emerging threat” for Pacific fishers (AR 010949) (emphasis added). 

The Gabriel study ranked as the most comprehensive study of fisher mortality in

California as of the time of the reversal. The authors collected data from a total of 167 dead

Pacific fishers found in both native California populations (AR 010938, 010940). The study

observed a notable increase in toxicosis, meaning direct death by poisoning of Pacific fishers. 

Earlier, from 2007–2011, the average annual death rate from toxicosis had been 5.6 percent. 

Later, however, from 2012–2014, the death rate from toxicosis increased to 18.7 percent per

year. This indicated a tripling of Pacific fisher deaths due to poisoning. Moreover, for the same

time periods, toxicant exposure also increased — from 79 percent to 85 percent (AR 010949),

meaning of the 167 dead Pacific fishers, 85 percent had anticoagulant rodenticides or other

toxicants in their bodies. The authors thus concluded that the threat of toxicant exposure was

“of increasing concern” (ibid.). Significantly, the Service failed to address the study’s key

findings and conclusions in its reversal. As such, this order finds that the Service’s assessment

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 The Gabriel study found 13 confirmed deaths but two additional mortalities were reported to the Service in a 2016

email by Dr. Greta Wengert (AR 038208), so the reversal correctly used 15 as the number of confirmed toxicosis cases.

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of the toxicant exposure stressor “r[an] counter to the evidence before [it]” and was accordingly

arbitrary and capricious. Motor Vehicles Mfrs., 463 U.S. at 43.

First, while the reversal acknowledged the 2015 Gabriel study in passing, it failed to

come to grips with the Gabriel study’s express finding that “mortality from and exposure to

toxicants appears to be on the rise” (AR 010951). The reversal further failed to grapple with the

Gabriel study’s finding that toxicant exposure had increased from 79 percent to 85 percent and

that toxicosis had more than tripled within a decade, despite acknowledging this fact in

response to Comment No. 263 (AR 000799). Instead, the reversal simply concluded — ipse

dixit style — that “the best available information at this time d[id] not support concluding that

the impacts described . . . r[ose] to the level of a threat, based on the insufficient evidence that

[anticoagulant rodenticides] or other toxicants [were] resulting in significant impacts at either

the population or rangewide scales” and that the Service was “not aware of any information that

indicate[d] use of [anticoagulant rodenticides] will increase within the range of the proposed

[distinct population segment] in the future” (AR 000727, 000799). 

Second, to the limited extent the reversal addressed the Gabriel study, the reversal

cherry picked the Gabriel study. It zeroed in on the study’s finding of 15 confirmed deaths

directly caused by toxicant exposure. The reversal characterized 15 as a negligible number of

deaths. This number, however, is not necessarily representative of the total number of cases of

toxicosis, as the reversal itself explained that “for any contaminant, collection of dead or

moribund individuals is likely to represent only a subset of the actual exposure or mortality

attributable to that contaminant” (AR 000799) (emphasis added). Moreover, the 15 confirmed

cases of direct poisoning must be viewed against the Pacific fisher’s small population size —

which the reversal failed to do (AR 000718).2

Third, the Service further erred in addressing the effects of sublethal exposure to

toxicants on the Pacific fisher population. The proposed listing found sublethal exposure likely

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widespread with detrimental effects (AR 000690). For example, the proposed listing found that

the effects of sublethal exposure likely included sickness and a decreased ability to heal from

injuries, which may increase the probability of mortality from other stressors, and that a

sublethal dose of anticoagulant rodenticide could cause significant clotting abnormalities and

hemorrhaging (ibid.). No new information since the proposed listing rebutted these original

findings. 

In addressing these effects, the reversal simply retreated into “uncertainty,” stating that

it was “uncertain” at what level of toxicant exposure fishers may be experiencing adverse

impacts. Specifically, the reversal noted that “the individual fishers within three populations . .

. ha[d] been found dead from other causes and also were found to be exposed to [anticoagulant

rodenticides] at sublethal levels with an unknown degree of impact to those individuals” and

that the Service lacked information on the population-level effects (AR 000727). Defendants

now further argue in their briefing that the 2015 Gabriel study found predation as the highest

contributing source of mortality for Pacific fishers, with anticoagulant rodenticide exposure

trailing behind as a source of Pacific fisher mortality. This shows, according to defendants, that

the Service reasonably concluded that toxicant exposure did not have a population-wide impact. 

With respect to predation, however, the 2015 Gabriel study pointed out that 

it would be difficult, if not impossible, to determine whether some

of the predation mortalities were ultimately going to result in

toxicosis. Many of the predation cases exhibited ante-mortem

hemorrhaging that could have been due directly to predation or

alternatively, [anticoagulant rodenticide] exposure. Anticoagulant

rodenticides have previously been shown to cause lethargy and

weakness in exposed animals . . . but teasing these two causes of

death apart was not possible

 (AR 010951). The Service itself even acknowledged this in the reversal, stating in response to

Comment No. 276 that it “agree[d] that exposure to [anticoagulant rodenticides] may predispose

fishers to predation due to the known physically debilitating effects” of anticoagulant

rodenticides on fishers (AR 000802). 

Moreover, with respect to uncertainty, the reversal cited a 2004 study by Erickson and

Urban, which evaluated, inter alia, the toxicity of widely-used anticoagulant rodenticide

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brodifacoum on minks (the Pacific fisher’s cousin), to conclude that “no consistent trends

associate residue concentrations with levels at which adverse effects occur” (AR 000727). In

the final species report (a companion to the reversal document), however, the Service used the

very same study to conclude that “a fisher foraging in an area illegally baited with over-thecounter brodifacoum products could easily consume enough exposed rodents over several days

to succumb to the poison, if fishers have approximately the same susceptibility to brodifacoum

that mink do” (AR 022750–54). The reversal failed to address this alarming conclusion. 

At bottom, that these Pacific fisher deaths could not be pinned on toxicant exposure

directly or that it may be uncertain as to what level of toxicant exposure fishers may be

experiencing adverse impacts do not provide the Service a rational connection to its conclusion

that toxicant exposure does not rise to the level of a threat. 

Our court of appeals has addressed how scientific “uncertainty” should be evaluated in

listing decisions. In Greater Yellowstone Coalition, Inc. v. Servheen, 665 F.3d 1015 (9th Cir.

2011), our court of appeals held that the Service failed to rationally support its conclusion that a

projected decline in whitebark pine, a key food source for bears, posed no threat to the

Yellowstone grizzly. There, the Service argued it did not know what impact whitebark pine

declines would have on the Yellowstone grizzly and pointed to the lack of data showing a

population decline due to whitebark pine loss as positive support for its delisting. Id. at

1028–30. Our court of appeals rejected this reasoning, explaining that the delisting “present[ed]

no data indicating that whitebark pine declines w[ould] not threaten the Yellowstone grizzly

population, and considerable data — demonstrating a relationship between pine seed shortages,

increased mortality, and decreased female reproductive success — pointing the opposite

direction.” Id. at 1030 (citing Tuscon Herpetological Soc’y v. Salazar, 566 F.3d 870, 879 (9th

Cir. 2009)). Thus simply stating that the impact was “uncertain” was insufficient. Rather, the

Service should have explained why the uncertainty favored delisting instead of some other

course of action, such as conducting further studies to help clarify the impact. Id. at 1028. 

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Although Greater Yellowstone involved a delisting, our court of appeals has extended

the same line of reasoning to where the Service reversed from finding a listing as “warranted

but precluded” to a final rule finding the listing as “not warranted.” See Ctr. for Biological

Diversity, 900 F.3d at 1060–62. Greater Yellowstone thus applies here, where the proposed

listing (and even the reversal) recounted the myriad of adverse effects of direct and indirect

exposure to anticoagulant rodenticides. The evidence also showed that exposure to

anticoagulant rodenticides was increasing. The reversal presented no direct data indicating that

toxicant exposure posed no threat to the Pacific fisher. 

“[I]t is not enough for [the Service] to simply invoke ‘scientific uncertainty’ to justify its

action.” Ctr. for Biological Diversity, 900 F.3d at 1072 (quoting Greater Yellowstone Coal.,

665 F.3d at 1028). Thus simply asserting the uncertainty as to the precise effects on the Pacific

fisher population does not serve as a rational connection to the Service’s conclusion that the

Pacific fisher’s increasing exposure to toxicants no longer rises to the level of a threat. Nor

does it rationally explain why not listing the Pacific fisher was justified “as opposed to taking

another course of action,” as “[p]ursuing another course of action may have been particularly

prudent given the ESA’s policy of ‘institutionalized caution.’ ” Ctr. for Biological Diversity,

900 F.3d at 1073 (quoting Ariz. Cattle Growers’ Ass’n v. Salazar, 606 F.3d 1160, 1167 (9th Cir.

2010)). The Service therefore acted in an arbitrary and capricious manner in qualitatively

assessing the threat of toxicant exposure. 

B. Population Trend Studies.

Defendants further argue that the Service treated the purportedly low confirmed

mortality in tandem with the Service’s assessment that the native Pacific fisher populations

were stable. This combined evaluation, according to defendants, supported the Service’s

conclusion that toxicant exposure does not rise to the level of a threat. In other words, the

Service used alleged population stability as circumstantial evidence supporting its position that

toxicant exposure, as well as other identified stressors, were not “operative threats.” Plaintiffs,

however, contend that the Service’s erroneous conclusion that the Pacific fisher populations are

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3 The Service found the fourth study by Zielinski, et al. to be inconclusive and thus purports to not have relied on

it (Dkt. No. 57 at 13; AR 000718). 

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persistent, i.e. stable, was based on limited and inconclusive trend data. This order agrees with

this criticism. 

In its reversal, the Service relied on three population trend studies in concluding that the

Pacific fisher population trend was either stable or not in decline. These studies refer to

“lambda,” which is a measure of the rate of a population’s growth or shrinkage — with a

lambda of one indicating no growth and no shrinkage, a lambda below one indicating shrinkage,

and vice versa. 

As to the native Southern Sierra Nevada population, a 2015 study by Sweitzer and

others reported a lambda range of 0.79 to 1.16 using a 95 percent confidence interval and an

estimated lambda of 0.966 (AR 000728). As to the native Northern California-Southwestern

Oregon population, two long-term studies — 2014 studies by Higley and others (“the Hoopa

study”) and Powell and others (“the Eastern Klamath study”) — reported an estimated lambda

of 0.992 (95 percent confidence interval of 0.883–1.100) and 1.06 (95 percent confidence

interval of 0.97–1.15), respectively (ibid.).3

 

Because all three studies “showed a population trend confidence interval which

straddled 1.0,” the Service concluded that the studies indicated a “statistically stable trend”

(Dkt. No. 57 at 12; AR 000728). This was the very same logical error the Service committed in

Natural Resources Defense Council, Inc. v. Rauch, 244 F. Supp. 3d 66 (D.D.C. 2017) (Judge

Randolph D. Moss), which rejected a similar interpretation of confidence intervals. There, the

Service declined to list the blueback herring as threatened under the Act because it concluded

that the herring’s populations were stable based on population abundance studies showing a 95

percent confidence interval, which included the null hypothesis of “zero” (the indication of no

change in abundance). This only meant, however, that the null hypothesis of population

stability could not be rejected. Id. at 90–91. To offer it as proof of population stability, as the

Service did, was an “error of logic.” Id. at 94. The district court accordingly held that the

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 This order notes that the Service seemed to have erroneously cited in the reversal Sweitzer et al. 2015b, p. 10,

rather than Sweitzer et al. 2015, p. 10, which actually contains the proposition cited for. 

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Service “failed to offer a ‘rational connection’ between the agency’s inability to reject the null

hypothesis that the trend had not changed, and its conclusion that the . . . population was, in

fact, stable.” Ibid.

So too here. 

Simply because the confidence intervals included 1.0, indicating that population stability

was possible, hardly proved it actually was 1.0 or greater. The confidence intervals also

included values below one. The confidence interval means nothing more than it is 95 percent

likely that the actual lambda is somewhere in the interval, somewhere between the low end of

the interval and its high end.

 This error in logic was exacerbated by the Service’s own observations made elsewhere

in the record. The Service’s own scientists understood (correctly) that a confidence interval

spanning 1.0 in connection with the Northern California-Southwestern Oregon population

studies was “an indication of uncertainty about the population trend” (AR 067328–29). 

Moreover, the reversal recognized that “the areas monitored for population trend are limited”

(AR 000728). Regarding two of these studies — the Hoopa and Eastern Klamath studies — the

final species report explicitly noted that “[g]iven the small portion of the [Northern

California-Southwestern Oregon] population sampled by the two study areas . . . it is difficult to

determine whether [that] population as a whole is increasing, decreasing, or stable” (AR

022641). 

As for the Sweitzer study, defendants now argue that the authors concluded that the data

“suggest[ed] stability or growth in some years” and “did not indicate a persistent decline in four

years from 2008–2009 to 2011–2012” (Dkt. No. 62 at 11; AR 024651). The reversal further

noted that “[a]lthough the authors express[ed] concern for the population and the need for

continued monitoring, their research suggests a basically stable trend when considered together

with information on population size and density” (AR 000718 (citing AR 024635)).4

 Both

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comments mischaracterized the authors’ conclusions. The reversal failed to come to grips with

the larger point of the Sweitzer study — namely, population growth for Pacific fishers in the

Southern Sierra Nevada segment was much more sensitive to adult female survival rates than

any other demographic rate and that female survival rates were 20 percent lower than 0.90 (AR

024635). The authors ultimately concluded that this female survival rate below 0.90 “impl[ied]

a greater challenge for maintaining self-sustaining fisher populations in the southern Sierra

Nevada region” (AR 024626). 

In Tuscon Herpetological Society v. Salazar, 566 F.3d 870 (9th Cir. 2009), our court of

appeals set aside the Service’s reversal of a proposed listing of the flat-tailed horned lizard as

arbitrary and capricious where the Service used “limited and inconclusive” population studies to

conclude that the lizard persisted in a substantial portion of its range. “If the science on

population size and trends is underdeveloped and unclear, the Secretary cannot reasonably infer

that the absence of evidence of population decline equates to evidence of persistence.” Id. at

879. There, the Service had cited in the reversal a study based on the emerging “capture-markrecapture” methodology that looked at two discrete sections of the lizard’s range as evidence of

no large population decline. Our court of appeals held that “[t]his single attenuated finding”

could not rationally support the Service’s “sweeping conclusion that viable lizard populations

persist.” Ibid. This was especially true given that, “[c]ontrary to the lesson the Secretary

dr[ew] from the study . . . the author’s primary conclusion [was] that the study’s population

estimates [could] serve as a ‘baseline for future monitoring.’ ” Ibid. 

Similarly here, the Service could not have reasonably used the mere fact that the

confidence intervals straddled 1.0 as proof of population stability. Moreover, the reversal

ignored the conclusion in the Sweitzer study itself that a female survival rate below 0.90

“impl[ied] a greater challenge for maintaining self-sustaining fisher populations in the southern

Sierra Nevada region” and that “[c]onsidering that there are likely fewer than 500 individual

fishers within California’s southern Sierra Nevada region and that these animals are exposed to

multiple known stressors, the population cannot be considered secure” (AR 024626, 024652). 

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Accordingly, the Service arbitrarily and capriciously relied on these population trend studies to

conclude Pacific fisher population stability. 

Defendants reply that although “the population studies on which the Service relied may

be imperfect, Tucson does not create a blanket prohibition on considering imperfect data” (Dkt.

No. 62 at 12). Defendants argue that these population studies were “the best available data

about fisher population trends” and thus were “not ‘limited and inconclusive’ ” (Dkt. No. 57 at

13). Defendants further contend that “[e]ven if the available scientific and commercial data are

‘quite inconclusive, [the Service] may — indeed must — still rely on it at that stage’ ” (Dkt. No.

57 at 13). Tucson, however, instructs that the Service may not affirmatively rely on limited and

inconclusive studies (which the Service itself recognizes as “imperfect”) as evidence of

persistence, and in turn use this “evidence” of persistence as proof that the stressors pose no

threat to the Pacific fisher population. See Tucson Herpetological Soc’y, 566 F.3d at 879. “The

limitations of the underlying data in this case mean that no such conclusion can be reached.” 

Pollinator Stewardship Council v. U.S. E.P.A., 806 F.3d 520, 531 (9th Cir. 2015). 

Defendants further emphasize that “[t]he absence of conclusive evidence of persistence,

standing alone, without persuasive evidence of widespread decline, may not be enough to

establish that the Secretary must list the [species] as threatened or endangered.” Tucson

Herpetological Soc’y, 566 F.3d at 879. This order, however, does not mandate that the Service

must list the Pacific fisher as threatened — rather, it merely holds that, with respect to the three

population studies, the Service failed to make a rational connection between the population

trend data and its conclusion that the Pacific fisher population is stable (which, in turn, was used

to support its conclusion on toxicant exposure). 

Defendants also point to Center for Biological Diversity v. U.S. Fish & Wildlife Service,

246 F. Supp. 3d 1272, 1282 (N.D. Cal. 2017) (Judge Jon S. Tigar), which upheld the Service’s

determination that there was no evidence that the coastal marten populations in Oregon were

declining, even in the absence of rigorous studies showing persistence. The district court,

however, upheld such a determination in light of the fact that there was no evidence to begin

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with that the Oregon coastal marten population was ever in decline, unlike here. Ibid. 

Moreover, the imperfect data (which constituted the best scientific data available) indicated that

the Oregon population was large and that the surveys “quickly detected the presence of coastal

martens.” Id. at 1281–82. In contrast, the district court rejected the Service’s argument that the

coastal marten populations in California were not declining where previous surveys

demonstrated significant population decline and the Service lacked current data confirming

continued decline. Id. at 1280–81.

Here, the absence of conclusive evidence of Pacific fisher persistence does not stand

alone. The Service does not dispute that the Pacific fisher population has declined dramatically

and that it remains notably small. As the Service itself noted, “[f]isher populations today in the

west coast States are smaller and their range has been reduced compared to historical

conditions” (AR 000730). And, the fisher has experienced well-documented population decline

“after the early 1900s by the combination of commercial trapping and loss of forest habitat from

logging and development” (AR 024639). 

***

Because this order finds remand appropriate based on the Service’s treatment of the

toxicant exposure threat and the Service’s flawed logic regarding population stability, it does

not and need not reach plaintiffs’ other criticisms regarding the Service’s treatment of other

stressors. This order, however, acknowledges that plaintiffs have raised plausible criticisms on

both those points. The Court suggests that on remand, the Service consider and address those

further points made by plaintiffs as well. 

2. COUNT II WAIVER.

Plaintiffs alleged in their complaint that the Service’s conclusion that the Pacific fisher

was not threatened throughout any significant portion of its range is contrary to the best

scientific information available (Dkt. No. 1 ¶ 64). Defendants argue that plaintiffs waived this

second claim for relief by failing to advance an argument in support of it in their opening brief

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for summary judgment (Dkt. No. 57 at 22). Because this order finds for plaintiffs as to their

first claim for relief, defendants’ motion for summary judgment on waiver is DENIED AS MOOT.

3. REMEDY. 

Plaintiffs request that the Service be ordered to prepare a new rule within ninety days

that is based “solely” on the “best scientific and commercial data available” (Dkt. No. 55 at 25).

Defendants argue that if the Service’s withdrawal of the proposed rule is found arbitrary

and capricious, then plaintiffs’ request for a new rule within ninety days should be rejected

(Dkt. No. 57 at 23–24). Defendants note that plaintiffs’ requested remedy deviates from their

requested relief in the complaint, as plaintiffs originally requested an order requiring the Service

to publish a final rule within six months (see Dkt. No. 1 ¶ 17). Defendants request that if the

Court is inclined to set a date for completing a revised rule, then it be granted leave to brief the

timeline in order to evaluate staffing and budget constraints (Dkt. No. 57 at 24). 

Plaintiffs’ request for an order directing the Service to prepare a new rule within ninety

days of remand is DENIED. The Service shall prepare a new rule by MARCH 22, 2019. 

Defendants’ request for leave to brief the timeline for remand is DENIED AS MOOT.

CONCLUSION

For the foregoing reasons, plaintiffs’ motion for summary judgment is GRANTED IN

PART. Defendants’ motions for summary judgment are DENIED. The Listing Withdrawal is

hereby VACATED and this action is REMANDED to prepare a revised rule that comports with this

order. 

IT IS SO ORDERED.

Dated: September 21, 2018. WILLIAM ALSUP

UNITED STATES DISTRICT JUDGE

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