[Federal Register Volume 77, Number 8 (Thursday, January 12, 2012)]
[Proposed Rules]
[Pages 1900-1908]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-479]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2011-0105; 4500030113]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Humboldt Marten as Endangered or Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding and initiation of status review.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the Humboldt marten (Martes 
americana humboldtensis) as endangered or threatened and designate 
critical habitat under the Endangered Species Act of 1973, as amended 
(Act). Based on our review, we find that the petition presents 
substantial scientific or commercial information indicating that 
listing the Humboldt marten may be warranted. Therefore, with the 
publication of this notice, we are initiating a review of the status of 
the Humboldt marten to determine if listing is warranted. To ensure 
that this status review is comprehensive, we are requesting scientific 
and commercial data and other information regarding the Humboldt 
marten. Based on the status review, we will issue a 12-month finding on 
the petition, which will address whether the petitioned action is 
warranted, as provided in section 4(b)(3)(B) of the Act.

DATES: To allow us adequate time to conduct this review, we request 
that we receive information on or before March 12, 2012. The deadline 
for submitting an electronic comment using the Federal eRulemaking 
Portal (see ADDRESSES section, below) is 11:59 p.m. Eastern Time on 
this date. After March 12, 2012, you must submit information directly 
to the Field Office (see FOR FURTHER INFORMATION CONTACT section 
below). Please note that we might not be able to address or incorporate 
information that we receive after the above requested date.

ADDRESSES: You may submit information by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Enter Keyword or ID box, enter Docket No. 
FWS-R8-ES-2011-0105, which is the docket number for this action. Then 
click on the Search button. You may submit a comment by clicking on 
``Send a Comment or Submission.''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R8-ES-2011-0105; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.
    We will post all information we receive on http://www.regulations.gov. This generally means that we will post any 
personal identifying information you provide us (see the Request for 
Information section below for more details).

FOR FURTHER INFORMATION CONTACT: Nancy J. Finley, Field Supervisor; by 
mail at Arcata Fish and Wildlife Office, 1655 Heindon Road, Arcata, CA 
95521; by telephone at (707) 822-7201; or by facsimile at (707) 822-
8411. If you use a telecommunications device for the deaf (TDD), please 
call the Federal Information Relay Service (FIRS) at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Request for Information

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly review the status of the species (status review). 
For the

[[Page 1901]]

status review to be complete and based on the best available scientific 
and commercial information, we request information on the Humboldt 
marten from governmental agencies, Native American tribes, the 
scientific community, industry, and any other interested parties. We 
seek information on:
    (1) The Humboldt marten's biology, range, and population trends, 
including:
    (a) Habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns;
    (d) Historical and current population levels, and current and 
projected trends; and
    (e) Past and ongoing conservation measures for the Humboldt marten, 
its habitat, or both.
    (2) The factors that are the basis for making a listing 
determination for a species under section 4(a) of the Act (16 U.S.C. 
1531 et seq.), which are:
    (a) The present or threatened destruction, modification, or 
curtailment of Humboldt marten habitat or its range;
    (b) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (c) Disease or predation;
    (d) The inadequacy of existing regulatory mechanisms; or
    (e) Other natural or manmade factors affecting its continued 
existence.
    If, after the status review, we determine that listing the Humboldt 
marten is warranted, we will propose critical habitat (see definition 
in section 3(5)(A) of the Act) under section 4 of the Act, to the 
maximum extent prudent and determinable at the time we propose to list 
the species. Therefore, we also request data and information on:
    (1) What may constitute ``physical or biological features essential 
to the conservation of the species,'' within the geographical range 
currently occupied by the species;
    (2) Where these features are currently found;
    (3) Whether any of these features may require special management 
considerations or protection;
    (4) Specific areas outside the geographical area occupied by the 
species that are ``essential for the conservation of the species;''and
    (5) What, if any, critical habitat you think we should propose for 
designation if the species is proposed for listing, and why such 
habitat meets the requirements of section 4 of the Act.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Submissions merely stating support for or opposition to the action 
under consideration without providing supporting information, although 
noted, will not be considered to provide the best information to 
support a determination. Section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is an endangered or threatened 
species must be made ``solely on the basis of the best scientific and 
commercial data available.''
    You may submit your information concerning this status review by 
one of the methods listed in the ADDRESSES section. If you submit 
information via http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the 
Web site. If your submission is made via a hardcopy that includes 
personal identifying information, you may request at the top of your 
document that we withhold this personal identifying information from 
public review. However, we cannot guarantee that we will be able to do 
so. We will post all hardcopy submissions on http://www.regulations.gov.
    Information and supporting documentation that we received and used 
in preparing this finding is available for you to review at http://www.regulations.gov, or by appointment, during normal business hours, 
at the U.S. Fish and Wildlife Service, Arcata Fish and Wildlife Office 
(see FOR FURTHER INFORMATION CONTACT section, above).

Background

    Section 4(b)(3)(A) of the Act requires that we make a finding on 
whether a petition to list, delist, or reclassify a species presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted. We are to base this finding on 
information provided in the petition, supporting information submitted 
with the petition, and information otherwise available in our files. To 
the maximum extent practicable, we are to make this finding within 90 
days of our receipt of the petition and publish our notice of the 
finding promptly in the Federal Register.
    Our standard for substantial scientific or commercial information 
within the Code of Federal Regulations (CFR) with regard to a 90-day 
petition finding is ``that amount of information that would lead a 
reasonable person to believe that the measure proposed in the petition 
may be warranted'' (50 CFR 424.14(b)). If we find that substantial 
scientific or commercial information was presented, we are required to 
promptly conduct a species status review, which we subsequently 
summarize in our 12-month finding.

Petition History

    On September 28, 2010, we received a petition dated September 28, 
2010, from the Center for Biological Diversity (CBD) and the 
Environmental Protection Information Center (EPIC), requesting that the 
Humboldt marten (Martes americana humboldtensis), a subspecies of the 
American marten, be listed as endangered or threatened and that 
critical habitat be designated in accordance with the Act. The document 
received clearly identified itself as a petition and included the 
requisite identification information for the petitioners, as required 
by 50 CFR 424.14(a). In a letter to the petitioners dated October 22, 
2010, we responded that we reviewed the information presented in the 
petition and determined that issuing an emergency regulation 
temporarily listing the species under section 4(b)(7) of the Act was 
not warranted. This finding addresses the petition.

Listable Entity Evaluation

    Under section 3(16) of the Act, we may consider for listing any 
species or subspecies of fish, wildlife, or plants, or any distinct 
population segment of vertebrate fish or wildlife which interbreeds 
when mature. Such entities are considered eligible for listing under 
the Act (and are, therefore, referred to as ``listable entities'') 
should they be determined to meet the definition of an endangered or 
threatened species. The petition states that genetics research 
indicates that the currently recognized species American marten (Martes 
americana) should be divided into two species--M. americana and M. 
caurina (CBD and EPIC 2010, p. 6). The petition indicates that if 
marten taxonomy is changed in the near future, the currently recognized 
subspecies Humboldt marten (M. americana humboldtensis) would likely be 
designated a subspecies of the newly designated species, M. caurina, 
and thus would likely be renamed M. caurina humboldtensis. Therefore, 
the petition requested listing as endangered or threatened one of the 
following: (1) The currently recognized Humboldt marten subspecies, M. 
americana humboldtensis; or (2) the Humboldt marten subspecies that may 
be redesignated as M. caurina humboldtensis; or (3) the Humboldt marten 
as a distinct population segment (DPS) of M. caurina (CBD and EPIC 
2010, pp. 2, 6).

[[Page 1902]]

    Historically, marten populations in coastal Oregon have not been 
included within the range of the Humboldt marten (see Taxonomy and 
Distribution section, below). The petition indicates, however, that 
because recent genetics research indicates that populations of American 
martens in coastal Oregon (currently Martes americana caurina) are more 
closely related to Martes americana humboldtensis in coastal northern 
California than to Martes americana caurina populations in the Cascade 
Range of Oregon (Slauson et al. 2009a, pp. 1339-1340), the petitioned 
and listable entity should include all marten populations in coastal 
northern California and coastal Oregon (CBD and EPIC 2010, pp. 7-10).
    The standard of review for a 90-day petition finding is ``that 
amount of information that would lead a reasonable person to believe 
that the measure proposed in the petition may be warranted.'' We 
determine that the petition has met the threshold for review in its 
characterization of currently designated American marten (M. americana) 
populations in coastal northern California and coastal Oregon as a 
potential listable entity. In our status review, we will thoroughly 
review all information relevant to the taxonomic status of Humboldt 
martens. For the purposes of this 90-day finding, the common name 
Humboldt marten refers to currently described American marten (M. 
americana) populations in coastal northern California and coastal 
Oregon, based on the rationale provided in the petition (CBD and EPIC 
2010, pp. 2, 6-8, 10) and research by Slauson et al. (2009a, pp. 1339-
1340).

Species Information

Taxonomy and Distribution
    The Humboldt marten (Martes americana humboldtensis) is a 
subspecies of the American marten and was first described by Grinnell 
and Dixon (1926, p. 411). The Humboldt marten is classified in the 
mammalian order Carnivora, family Mustelidae (weasels, otters, 
badgers), and subfamily Mustelinae (martens, fisher, wolverine, 
weasels). Clarke et al. (1987, p. 1) recognized eight subspecies of the 
American marten; Wilson and Reeder (2005, p. 608) recognized 12 
subspecies; and Hall and Kelson (1959, p. 900) and Hall (1981, pp. 981-
985) recognized 14 subspecies. Differences between the subspecies are 
based on morphological and pelage characteristics (Hall and Kelson 
1959, p. 900; Hall 1981, pp. 983-984) or cranial characters and fossil 
history (Clarke et al. 1987, p. 1). The Humboldt marten is recognized 
as a distinct subspecies of the American marten by all of the 
aforementioned authors.
    The American marten occurs throughout northern North America, 
reaching its southjrnmost extent in the Sierra Nevada of California and 
the southern Rocky Mountains of New Mexico (Gibilisco 1994, p. 66). The 
historical range of the Humboldt marten is based on the catch of 
licensed trappers in California for the 5-year period 1919-1924 
(Grinnell and Dixon 1926, p. 415), and includes coastal northern 
California, throughout the coast redwood (Sequoia sempervirens) zone 
from the Oregon border south to Sonoma County (Grinnell and Dixon 1926, 
p. 415; Grinnell 1933, p. 100; Grinnell et al. 1937, p. 209). 
Historically, M. a. caurina has been recognized to occur north of the 
coast redwood zone in western Oregon, Washington, and British Columbia 
(Bailey 1936, p. 296; Hall 1981, p. 983; Zielinski et al. 2001, p. 
479).
    In northwestern California, the Klamath River separates the 
historical range of the Humboldt marten from the range of the Sierra 
Nevada marten (M. a. sierrae), which occurs from the Salmon-Trinity 
Mountains in interior northwestern California, east to the Cascades, 
and south throughout the Sierra Nevada (Hall 1981, p. 983; Zielinski et 
al. 2001, p. 479). Slauson and Zielinski (2004, p. 62) suggest that the 
xeric forest types in the river's canyon may act as a physical barrier 
between these two subspecies.
    In 2009, Slauson et al. (2009a, p. 1338) compared mitochondrial DNA 
sequence diversity of martens from extant marten populations within the 
described ranges of M. a. humboldtensis, M. a. caurina, and M. a. 
sierrae, with a 1927 museum specimen of M. a. humboldtensis. Martens 
from coastal northern California share a haplotype with the 1927 museum 
specimen, supporting the hypothesis that the existing population in 
coastal northern California represents descendants of the historical 
population of Humboldt martens described by Grinnell and Dixon in 1926 
(Slauson et al. 2009a, p. 1337). However, this same haplotype also 
occurs in coastal Oregon populations of M. a. caurina, but is absent 
from the Oregon Cascades population of M. a. caurina and from M. a. 
sierrae, indicating that martens of coastal Oregon are genetically more 
similar to martens from coastal northern California than they are to 
martens in the Oregon Cascades (Slauson et al. 2009a, p. 1340). The 
results further suggest that the historically defined range boundary 
between M. a. humboldtensis and M. a. caurina at the Oregon-California 
border may not be valid, and that coastal Oregon martens are part of 
the same taxonomic group as Humboldt martens in coastal northern 
California (Slauson et al. 2009a, p. 1340). Slauson et al. (2009a, p. 
1340) concluded that, even though the coastal northern California and 
coastal Oregon marten populations share a common haplotype, due to 
small sample sizes, additional genetic analyses are necessary to 
confirm the genetic relationship. Slauson et al. (2009a, p. 1337) noted 
that there are no known contemporary or historical biogeographic 
barriers to prevent north-south movement of martens between coastal 
northern California and coastal Oregon. Therefore, a genetic 
relationship between coastal marten populations in northern California 
and Oregon would not be unexpected. As described above in Listable 
Entity Evaluation, for the purposes of this 90-day finding, we conclude 
that substantial information was provided in the petition indicating 
that M. americana populations in coastal northern California and 
coastal Oregon may constitute a valid listable entity. We will evaluate 
all relevant information on genetics and taxonomy in our status review.
Population Status
    Zielinski and Golightly (1996) reviewed all published and 
unpublished historical information on the Humboldt marten, and the 
results of contemporary (1989-1995) field surveys conducted within its 
historical range, to determine the status of the subspecies in the 
redwood zone of California (redwoods also occur in adjacent Curry 
County, Oregon). They concluded that the marten population in the 
northern Coast Ranges of California significantly declined during the 
20th century and that the last verifiable record was 50 years old, 
suggesting the subspecies was very rare, if not extinct. However, in 
1996 and 1997, martens were detected at two survey stations in 
northwestern California on the Six Rivers National Forest (Zielinski et 
al. 1998, p. 1). These 1996-1997 presence-absence marten surveys were 
conducted within presumed suitable habitat, throughout the historical 
range of the Humboldt marten in northwestern California as well as in 
extreme southern coastal Oregon. Besides the marten detections in 
northwestern California, martens were also detected at survey stations 
within 3 of the 19 sample units placed in southern coastal Oregon 
(Zielinski et al. 1998, p. 2). The southern-most Oregon detection is 
over 50 miles (mi)

[[Page 1903]]

(80 kilometers (km)) from the nearest California detection. Much of the 
habitat in this intervening area is suitable for martens, but 
presumably unoccupied as of the late 1990s.
    The coastal northern California marten population rediscovered in 
1996 and 1997 is located in the north-central portion of the described 
range for M. a. humboldtensis (Grinnell and Dixon 1926, p. 413; Slauson 
et al. 2009a, p. 1338). Based on results of a 2000-2001 grid-based 
survey of the single marten population rediscovered in coastal northern 
California in 1996, Slauson et al. (2009b, p. 13) concluded that the 
entire Humboldt marten population in California likely consists of 
fewer than 100 individuals. The Humboldt marten appears to have been 
extirpated from greater than 95 percent of the range it occupied in 
California in the early 1900s (Grinnell et al. 1937, p. 209), with the 
single known extant population occupying an estimated area of only 
170,000 acres (ac) (68,797 hectares (ha)) (Service 2010, p. 34). 
Further, the Humboldt marten population in California is estimated to 
have undergone a 42 percent decline in occupancy between grid-based 
surveys conducted in 2000-2001 and 2008 (Slauson et al. 2009b, p. 10).
    Martens in coastal Oregon are currently known from only two 
disjunct populations--one in central coastal Oregon and one in southern 
coastal Oregon--both of which are believed to be in decline based 
mainly on a reduction in the number of martens trapped and anecdotal 
observations over time (Zielinski et al. 2001, p. 478; Slauson and 
Zielinski 2009, p. 36). No systematic grid-based surveys have been 
conducted on, nor population estimates made for, the two populations of 
martens in coastal Oregon. Concerns about the viability of the two 
known marten populations in coastal Oregon have been expressed (Slauson 
et al. 2009a, p. 1340).
    Published literature on the Humboldt marten largely deals with 
distribution, habitat selection, home range, diet, and genetics. Little 
is known about Humboldt marten reproductive biology, demographics, 
disease, or predation. Where data specific to the Humboldt marten are 
lacking, we present published information for other American marten 
subspecies, with the supposition that all subspecies of the American 
marten share certain characteristics and behaviors.
Biology
    The American marten has a long, slender body with relatively large 
rounded ears, short limbs, and bushy tail (Clark et al. 1987, p. 1). 
American martens have triangular faces with muzzles less pointed than 
those of foxes. The tail constitutes about one-third of the total body 
length (Powell et al. 2003, p. 636). Each well-furred paw includes five 
toes (Powell et al. 2003, p. 636). Total length of American martens is 
between 19.7 and 26.8 inches (in) (50 and 68 centimeters (cm)) and 
adults weigh 1.1 to 3.1 pounds (lb) (0.5 to 1.4 kilograms (kg)), 
depending on sex and subspecies (Buskirk and McDonald 1989, p. 999); 
males are 20 to 40 percent larger than females (Buskirk and Zielinski 
1997, p. 17). The color of the long, silky, dense fur ranges from pale 
yellowish buff to tawny brown to almost black (Clark et al. 1987, p. 
1). The color of the head is usually lighter than the body, and the 
legs and tail are darker (Clark et al. 1987, p. 1).
    Compared to the Sierra Nevada marten, the other subspecies of 
American marten that occurs in California, the Humboldt marten is 
reported to be darker, with a richer golden tone, and to have less 
orange and yellow in the throat patch, a smaller skull (Grinnell and 
Dixon 1926, p. 411), and smaller and less crowded premolars and molars 
(Buskirk and Zielinski 1997, p. 17). Grinnell et al. (1937, p. 207) 
added that the Humboldt marten had ``* * * far less orange-yellow color 
on the throat and chest, and the usual area of this color is much 
broken up by coarse spots and marblings of body brown.'' Hagmeier 
(1961, p. 124) describes the Humboldt marten as a very small marten, 
perhaps the smallest subspecies of American marten.
    Sexual maturity for American martens occurs by 1 year of age, but 
effective breeding may not occur before 2 years of age (Powell et al. 
2003, p. 638). Mating occurs in July or August and the gestation period 
varies from 220 to 276 days (Strickland et al. 1982, p. 602). Birth 
occurs in late March or April, due to delayed implantation in which the 
embryos remain in a state of arrested development (Strickland et al. 
1982, p. 602). Kits are completely dependent at birth and weaned at 
about 42 days (Buskirk and Ruggiero 1994, p. 17). The male apparently 
takes no part in rearing the young, which disperse in late summer or 
autumn (Strickland et al. 1982, p. 603). American martens produce an 
average of slightly less than three young per female with one litter 
per year (Strickland et al. 1982, p. 602). For a mammal of their size, 
American martens have relatively low reproductive rates, but are long-
lived (up to 15 years in captivity and 14.5 years in the wild) 
(Strickland and Douglas 1987, p. 535), suggesting a relatively slow 
potential recovery rate from population-level impacts (Buskirk and 
Ruggiero 1994, p. 16).
    Slauson and Zielinski (2007a, p. 55) characterized the diet of 
Humboldt martens by scat analysis and found that mammals (in 93 percent 
of scats) and berries (in 85 percent of scats) were the most frequently 
occurring items, followed by birds (in 21 percent of scats), insects 
(in 20 percent of scats), and reptiles (in 7 percent of scats). Sciurid 
rodents (especially Tamias species (spp.)) and Murid voles 
(Clethrionomys californicus and Arborimus spp.) were the most common 
mammal species found in Humboldt marten scats (Slauson and Zielinski 
2007a, p. 55). The frequency of berries in the diet of the Humboldt 
marten was the highest reported in diet studies of the American marten; 
the frequency of birds was also among the highest reported (Slauson and 
Zielinski 2007a, p. 55).
    Strickland et al. (1982, p. 607) summarized reports of American 
martens being preyed upon by coyotes (Canis latrans), fishers (Martes 
pennanti), red foxes (Vulpes vulpes), cougars (Puma concolor), eagles 
(Aquila chrysaetos and Haliaeetus leucocephalus), and great horned owls 
(Bubo virginianus). Bull and Heater (2001, p. 3), in their northeastern 
Oregon study area, documented 18 American martens killed by predators: 
8 by bobcats (Lynx rufus), 4 by raptors, 4 by other American martens, 
and 2 by coyotes.
    Slauson and Zielinski (2006, p. 65) estimated seasonal (summer-
fall) home range size for Humboldt martens in California using the 100 
percent minimum convex polygon method (a polygon created by drawing a 
line connecting the outer locations). Adult male home ranges averaged 
1,322 ac (535 ha); the home range for a single adult female with one 
kit was 315 ac (127 ha). Juvenile female home ranges averaged 1,491 ac 
(603 ha); the single juvenile male home range was 453 ac (183 ha).
Habitat
    Historical records of the distribution of Humboldt martens in 
California suggest that the subspecies was closely tied to coastal old-
growth redwood forests (Slauson et al. 2003, p. 3). However, the one 
known remnant Humboldt marten population in California occurs in the 
north-central portion of the described range in an area dominated by 
Douglas-fir (Pseudotsuga menzesii) and tanoak (Lithocarpus densiflora) 
forest associations (Slauson et al. 2007, p. 459). This population uses

[[Page 1904]]

two structurally distinct, fog-influenced forest types, one on 
serpentine (a mineral or rock consisting of a hydrous magnesium 
silicate and usually having a dull green color and often a mottled 
appearance) soils and one on more productive non-serpentine soils 
(Slauson 2003, p. 59; Slauson et al. 2009b, p. 3). The non-serpentine 
habitats contain old-growth Douglas-fir forests, and the serpentine 
types contain mixed conifer forests that include Douglas-fir, sugar 
pine (Pinus lambertiana), western white pine (P. monticola), and 
lodgepole pine (P. contorta) (Slauson et al. 2009b, p. 3).
    At the home range scale, Humboldt martens in California select the 
largest available patch sizes of old-growth, old-growth and late-mature 
(i.e., late-successional), and serpentine habitat (Slauson et al. 2007, 
p. 466). Slauson et al. (2009b, p. 12) found that the biggest 
difference between sites in California with stable Humboldt marten 
occupancy versus unstable occupancy is patch size of old-growth forest, 
with sites with more stable Humboldt marten occupancy associated with 
larger patches of old-growth forest. The probability that a Humboldt 
marten is detected increases as the following home range 
characteristics increase in size: largest contiguous patch of late-
successional forest; total amount of late-successional forest; and 
total area of serpentine habitat (Slauson 2003, p. 67). In non-
serpentine habitats, conifer-dominated, late-successional stands with 
dense shrub cover in patches greater than or equal to 445 ac (180 ha) 
are estimated to be a minimum criterion to identify potential Humboldt 
marten home range areas (Slauson 2003, p. 70).
    Compared to martens in the Sierra Nevada and Cascade mountains, 
Humboldt martens occupy low-elevation areas with little or no snowfall 
and select forest habitats with some distinctly different features, 
such as dense, extensive shrub cover (Slauson et al. 2009b, p. 3). 
Serpentine habitats occupied by Humboldt martens have open tree 
canopies, dense shrub cover, and an abundance of boulder piles, while 
non-serpentine sites have closed, multi-layered tree canopies, dense 
shrub cover, and older age-class stands (Slauson 2003, p. 59). 
Serpentine sites sometimes lack trees, suggesting that dense shrub 
layers may provide the necessary overhead cover (Slauson 2003, pp. 60-
61). In addition, prey species, such as chipmunks (Tamias spp.) and 
golden-mantled ground squirrels (Spermophilus lateralis), may use 
boulder-sized surface rocks for escape cover in serpentine sites where 
trees are sparse (Slauson 2003, p. 61). Recent Humboldt marten 
population monitoring suggests that serpentine areas may represent 
lower quality habitat than late-successional Douglas-fir forest 
(Slauson et al. 2009b, p. 12). In non-serpentine habitats, Humboldt 
martens use old-growth stands much more than expected based on 
availability, use late-mature stands commensurate with availability, 
and make little or no use of all other seral stages (Slauson et al. 
2007, p. 462). All earlier seral stages are selected against, probably 
because of the lack of one or more key structural features (Slauson 
2003, p. 62). Dense shrub cover is the most consistent habitat feature 
at sites selected by Humboldt martens in both serpentine and non-
serpentine habitats (Slauson et al. 2007, p. 465). Humboldt martens 
show the strongest selection for conifer stands with greater than 80 
percent shrub cover and select against stands with less than 60 percent 
shrub cover (Slauson and Zielinski 2007b, p. 242). Plant species 
dominating the shrub layers are shade-tolerant, long-lived, mast- and 
berry-producing species, including salal (Gaultheria shallon), 
evergreen huckleberry (Vaccinium ovatum), Pacific rhododendron 
(Rhododendron macrophyllum), and shrub oaks (huckleberry oak (Quercus 
vaccinifolia) and bush tanoak (Lithocarpus densiflorus var. 
echinoides)) (Slauson and Zielinski 2009, p. 42). In contrast, Humboldt 
martens do not use disturbance-associated species of shrubs, such as 
Ceanothus spp. (Slauson and Zielinski 2009, p. 42). Dense stands of 
mature shrubs provide refuge from predators, cover for prey species, 
and mast (berries and acorns) for prey species and Humboldt martens, 
and such stands may also deter larger-bodied competitors, such as 
fisher and gray fox (Urocyon cinereoargenteus), by limiting their 
foraging abilities (Slauson and Zielinski 2009, p. 42). Shrubs also 
contribute to the formation of some resting locations and resting 
structures (Slauson and Zielinski 2009, p. 42).
    During the late summer and fall, Humboldt martens in California 
used cavities, den chambers, and broken tops of standing dead trees for 
87 percent of their resting locations, and branch platforms, ground 
sites, and basal hollows for the remainder of their resting locations 
(Slauson and Zielinski 2009, p. 39). Large snags were the most 
frequently used resting structure with mean diameter-at-breast-height 
(dbh) for conifers of 36.6 in (93 cm) (Slauson and Zielinski 2009, p. 
40). Conifer logs used as resting structures had a mean diameter of 
29.5 in (75 cm) (Slauson and Zielinski 2009, p. 40). Forty-two percent 
of the resting structures used in serpentine habitats were located in 
rock and shrub clumps (Slauson and Zielinski 2009, p. 40). All resting 
sites in serpentine and non-serpentine habitats had dense shrub cover 
(Slauson and Zielinski 2009, p. 42).
    Availability of denning habitat is essential to successful 
recruitment and persistence of American marten populations (Ruggiero et 
al. 1998, p. 663). American marten natal dens, used by mothers and 
neonatal young, are typically located in cavities in very large logs, 
snags, or live trees, while maternal dens, used by mothers and older 
but still dependent young, tend to be in less specialized structures 
similar to resting sites (Ruggiero et al. 1998, p. 663). Slauson and 
Zielinski (2009, p. 40) observed one adult female Humboldt marten with 
a single kit at three maternal den structures: (1) A 26-in (66-cm) dbh 
live chinquapin (Chrysolepis chrysophylla), (2) the broken top of a 
44.5-in (113-cm) dbh live Douglas-fir, and (3) in a 45.3-in (115-cm) 
dbh Douglas-fir snag.

Evaluation of Information for This Finding

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations at 50 CFR part 424 set forth the procedures for adding a 
species to, or removing a species from, the Federal Lists of Endangered 
and Threatened Wildlife and Plants. 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) of the Act:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    In considering what factors might constitute threats, we must look 
beyond the mere exposure of the species to the factor to determine 
whether the species responds to the factor in a way that causes actual 
impacts to the species. If there is exposure to a factor, but no 
response, or only a positive response, that factor is not a threat. If 
there is exposure and the species responds negatively, the factor may 
be a threat and we then attempt to determine how significant a threat 
it is. If the threat is significant, it may drive or contribute to the 
risk of extinction of the species,

[[Page 1905]]

such that the species may warrant listing as endangered or threatened 
as those terms are defined by the Act. This does not necessarily 
require empirical proof of a threat. The combination of exposure and 
some corroborating evidence of how the species is likely impacted could 
suffice. The mere identification of factors that could impact a species 
negatively may not be sufficient to compel a finding that listing may 
be warranted. The information must contain evidence sufficient to 
suggest that these factors may be operative threats that act on the 
species to the point that the species may meet the definition of 
endangered or threatened under the Act.
    In making this 90-day finding, we evaluated whether information 
regarding threats to the Humboldt marten, as presented in the petition 
and in other information available in our files, is substantial, 
thereby indicating that the petitioned action may be warranted. Our 
evaluation of this information is presented below.

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

    The petition states that the primary cause of population decline 
and extirpation of martens in coastal northern California and coastal 
Oregon is loss of old-growth coniferous forest habitat due to logging 
(CBD and EPIC 2010, p. 20). According to the petition, logging 
threatens Humboldt marten populations because martens require large 
areas of unfragmented, old-growth forest to survive and because logging 
reduces the amount of available habitat and key Humboldt marten habitat 
structural elements, such as large standing and dead conifers, down 
woody debris, and a dense understory of shade-tolerant shrubs (CBD and 
EPIC 2010, pp. 20-23).
    Zielinski et al. (2001, p. 487) postulated that timber harvest in 
the redwood region was the most plausible reason for the continued 
absence of Humboldt martens from most of the coastal range of 
northwestern California. Zielinski et al. (2001, p. 487) concluded that 
because martens typically are associated with old forests with a 
diversity of large structural features, it is likely that the intensity 
of timber harvest, especially on private lands, has reduced the habitat 
value over much of the coastal northern California region. Large areas 
of the Humboldt marten's range in California and Oregon are located on 
private commercial timberlands (Zielinski et al. 2001, pp. 478, 484; 
CBD and EPIC 2010, pp. 23, 32). Most of the areas within the Humboldt 
marten's range in California and Oregon not located on private lands 
are located on U.S. Forest Service (Forest Service) lands, but timber 
harvesting occurs on most of these Forest Service lands (CBD and EPIC 
2010, pp. 23, 29-32).
    The petition also states that over the long-term, wildfire plays a 
role in developing the habitat components on which martens depend, but 
because the Humboldt marten's habitat has been so severely reduced by 
logging, wildfires are now a threat to the subspecies (CBD and EPIC 
2010, p. 24). Slauson and Zielinski (2004, p. 63) reported that, due to 
the subspecies' critically low population size and restricted range in 
northwestern California, fire threatens the Humboldt marten with short-
term loss and fragmentation of suitable habitat. Fires in 1998 and 2008 
burned approximately 28 percent of the range currently occupied by 
Humboldt marten in northwestern California (Service 2010, p. 19). The 
Biscuit Fire, one of Oregon's largest fires in recorded history, burned 
a total area of approximately 500,000 ac (202,343 ha) (Forest Service 
2009), part of which overlapped the range of the southernmost 
population of Humboldt marten in coastal Oregon. Fifty percent of the 
total burn area burned very hot, with more than 75 percent of the 
vegetation killed (Forest Service 2009). Post-fire site visits to some 
of the areas burned in northwestern California in 2008 showed that the 
dense shrub understory was removed, likely reducing the suitability and 
increasing fragmentation of these areas for the Humboldt marten over 
the short term (Slauson et al. 2009b, p. 11). In the cool, moist 
coastal forests of northern California, fires pose a relatively low 
risk to the Humboldt marten and its habitat. However, the habitat of 
the current Humboldt marten population in northwestern California 
occurs primarily in the relatively warm and dry Douglas-fir-tanoak 
communities farther inland and at higher elevations and, thus, is more 
vulnerable to lightning-ignited fires. Further, even low-intensity 
fires can remove the dense shrub understory that is important to 
Humboldt martens, reducing habitat quality and increasing fragmentation 
of suitable habitat.
    The petition states that recreational activities, including off-
highway vehicles, snowmobiles, dirt bikes, and camping could degrade 
marten habitat, interfere with marten behavior, and cause martens to 
shift to less suitable habitat (CBD and EPIC 2010, p. 24). The petition 
recognizes that threats posed to Humboldt marten populations by 
recreation are unknown, and that due to the remoteness of Humboldt 
marten habitat and dense shrub cover preferred by the subspecies, the 
threat posed by recreation is likely low (CBD and EPIC 2010, p. 25). 
While certain recreational activities may have localized impacts on 
marten habitat, information in the petition and in our files does not 
indicate that recreational activities are having population-level 
impacts that threaten the Humboldt marten.
Summary for Factor A
    In summary, we find that the information provided in the petition, 
as well as other information readily available in our files, presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted due to the present or threatened 
destruction, modification, or curtailment of the Humboldt marten's 
habitat or range from timber harvesting and fire. We will review the 
possible effects of these threats to Humboldt marten more thoroughly in 
our status review.

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

    The petition states that historical trapping was the primary 
contributor to the decline of martens in California, including the 
portions of Humboldt, Del Norte, and Siskiyou Counties where the small 
extant population of the Humboldt marten occurs (CBD and EPIC 2010, p. 
25). In 1946, the California Fish and Game Commission closed the marten 
trapping season in all or parts of Del Norte, Humboldt, Siskiyou, and 
Trinity Counties due to declining harvests (Twining and Hensley 1947, 
p. 136). However, Humboldt marten populations in coastal northern 
California have not recovered, despite decades of protection from 
trapping (Slauson and Zielinski 2004, p. 61).
    While trapping of martens as furbearers in California is no longer 
legal, the petition states that the threat posed to Humboldt martens by 
accidental capture and poaching in California is magnified by other 
threats such as small population size, population isolation, and 
habitat fragmentation from logging and fire (CBD and EPIC 2010, p. 25). 
In California, it is legal to trap other mammals that may occur in 
Humboldt marten habitat, including bobcats and gray fox (California 
Code of Regulations, Title 14, Sections 461 and 478), and Humboldt 
martens may be captured incidentally in traps set for these species. 
Body-gripping traps (such as steel-jawed leghold, padded leghold,

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conibear, and snares) were banned in California in 1998 (California 
Fish and Game Code Section 3003.1). Only non-body-gripping traps, such 
as cage and box live traps, are legal in California. No information was 
provided in the petition, nor is any information available in our 
files, to determine the extent of incidental trapping-related injury or 
mortality from non-body-gripping traps. However, the use of box or cage 
live traps suggests that, if trapped, Humboldt martens are more likely 
to be released alive and unharmed than if body-gripping or other lethal 
trap types were allowed. Due to the remote location of habitat occupied 
by the Humboldt marten and the above restrictions, current mortalities 
and injuries from incidental capture of Humboldt martens in 
northwestern California are likely rare.
    Additionally, current scientific survey techniques use nonlethal 
methods, such as track-plates, camera stations, and live traps, and are 
thus not likely to result in population-level impacts to the Humboldt 
marten. While injury from accidental capture and poaching may affect 
individual Humboldt martens in California, neither information in the 
petition nor information in our files indicates that accidental capture 
and poaching in California are likely to have a population-level effect 
or threaten the Humboldt marten.
    Martens are still legally trapped as furbearers in Oregon, and the 
petition states that trapping remains a threat to martens in coastal 
Oregon (CBD and EPIC 2010, p. 25). The petition states that the threat 
posed to Humboldt martens by legal trapping in Oregon is magnified by 
other threats such as small population size, population isolation, and 
habitat fragmentation from logging and fire (CBD and EPIC 2010, p. 25). 
Information in the petition indicates that martens can be trapped 
throughout Oregon between November 1 and January 31 with the purchase 
of a furtakers' license (CBD and EPIC 2010, p. 25). Although trapping 
mortality of martens is a potential concern because marten populations 
in coastal Oregon are considered small and isolated (see Population 
Status section), most martens trapped in Oregon are taken from the 
Cascade Range and Blue Mountains, and trapping harvest of martens in 
the Oregon Coast Range is rare (Oregon Department of Fish and Wildlife 
2010). We therefore conclude that information presented in the petition 
and available in our files does not indicate that furbearer trapping in 
Oregon is a threat to Humboldt marten.
Summary for Factor B
    In summary, we find that the information provided in the petition, 
as well as other information readily available in our files, does not 
present substantial scientific or commercial information indicating 
that the the petitioned action may be warranted due to overutilization. 
However, we will review the possible effects of furbearer trapping in 
Oregon on Humboldt marten more thoroughly in our status review.

C. Disease or Predation

Disease
    The petition recognizes that disease in the Humboldt marten has not 
been studied, but states that the Humboldt marten is potentially 
threatened by disease given the subspecies' extremely small population 
size (CBD and EPIC 2010, p. 26). Numerous pathogens are known to cause 
severe disease in mustelids (Brown et al. 2008, pp. 5-6), but disease 
exposure in the Humboldt marten has not been studied. Strickland et al. 
(1982, p. 607) noted that American martens in their study area in 
central Ontario, Canada, tested positive for toxoplasmosis, Aleutian 
disease (a carnivore parvovirus), and leptospirosis; however, none of 
these was known to be a significant mortality factor. Brown et al. 
(2008) determined rates of pathogen exposure for the congeneric (member 
of the same genus, Martes) fisher in northwestern California on the 
Hoopa Valley Indian Reservation--located less than 6.2 mi (10 km) south 
of the nearest Humboldt marten verified detection--and demonstrated 
that fishers were exposed to several serious pathogens including canine 
distemper virus, canine parvovirus, and West Nile virus. Of the 15 
radio-collared fishers found dead on the Hoopa Valley Indian 
Reservation during the pathogen study, 2 had been exposed to canine 
distemper virus and 6 to canine parvovirus (Brown et al. 2008, p. 3). 
Evidence of canine distemper virus infection has been reported in all 
families of terrestrial carnivores, including the family Mustelidae 
that includes martens and fishers (Deem et al. 2000, p. 441). In fact, 
mustelids are among the species most susceptible to canine distemper 
disease (Deem et al. 2000, p. 443). For example, black-footed ferrets 
(Mustela nigripes) are highly susceptible to natural canine distemper 
infection and have a fatality rate close to 100 percent (Bernard et al. 
1984). Because canine distemper is highly contagious, and viral 
shedding may follow infection for 60-90 days (Greene and Appel 1990), 
it is reasonable to assume that infected fishers on the Hoopa Valley 
Indian Reservation, especially dispersing juveniles, could infect the 
nearby Humboldt marten population. Even at low exposure rates, canine 
distemper has the potential to be a threat to one or more of the small 
extant Humboldt marten populations.
    Research cited in the petition and information in our files 
indicates that fishers located in close proximity to Humboldt marten 
occurrences in northwestern California have been exposed to canine 
distemper, a disease that can be transmitted between different species 
of carnivores and that can cause high levels of mortality in 
carnivores, including species within the Mustelidae family. Estimated 
size of the northwestern California Humboldt marten population is 
small, so an outbreak of canine distemper or other lethal carnivore 
disease could have a population-level impact and pose a threat to this 
population.
Predation
    The petition states that predation is a significant threat to the 
Humboldt marten, especially because the subspecies is highly vulnerable 
to mortality events and further population decline due to its small 
population size (CBD and EPIC 2010, p. 25). Timber harvesting practices 
that result in reduced shrub layers may result in increased 
vulnerability of Humboldt martens to predation by larger carnivores, 
such as fishers and gray foxes. Fishers and gray foxes typically occupy 
forest types where shrub densities are naturally lower and are rarely 
detected in coastal forest with extensive shrub cover (Slauson and 
Zielinski 2007b, p. 242). Dense, spatially extensive shrub layers may 
provide smaller-bodied Humboldt martens an advantage over other larger-
bodied carnivores (Slauson et al. 2007, p. 466), so that the removal of 
these layers may put the Humboldt marten at risk of increased 
predation. Although there may be associations between shrub cover and 
risk of predation in forests where Humboldt martens occur, we did not 
find information in the petition or in our files indicating that 
elevated predation rates may be a threat to the continued existence of 
Humboldt martens.
    The petition states that recreational activities, including off-
highway vehicles, dirt bikes, hiking, and camping, could affect 
Humboldt marten behavior, possibly exposing the Humboldt marten to 
increased predation. The petition acknowledges that the level of the 
threat from these recreational activities is unknown, but likely low 
due to the remoteness of the

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currently occupied range of the Humboldt marten. We conclude that 
information in the petition and information in our files does not 
support the assertion in the petition that predation is a threat to 
Humboldt marten.
Summary of Factor C
    In summary, we find that the information provided in the petition, 
as well as other information readily available in our files, presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted due to disease as a result of the 
threat posed by canine distemper or other lethal carnivore diseases on 
Humboldt marten. We will review the possible effects of these threats 
to Humboldt marten more thoroughly in our status review.

D. The Inadequacy of Existing Regulatory Mechanisms

    The petition states that existing regulatory mechanisms do not 
adequately protect the Humboldt marten on Federal, State, tribal, or 
private lands (CBD and EPIC 2010, pp. 28-33). The petition further 
states that martens are still legally trapped in coastal Oregon and 
that existing regulatory mechanisms are inadequate to protect habitat 
for the martens in coastal northern California and coastal Oregon (CBD 
and EPIC 2010, p. 28).
    The petition states that large areas of the Humboldt marten's 
historical range and current range occur on privately owned commercial 
timberlands where existing regulatory mechanisms do not protect 
Humboldt martens from habitat loss and degradation due to timber 
harvesting (CBD and EPIC 2010, p. 29). As mentioned in the Factor A 
section above, large areas of the Humboldt marten's current range in 
coastal northern California and coastal Oregon occur on private 
commercial timberland. Information in our files supports the assertion 
that forest management practices on these private commercial 
timberlands may not be compatible with habitat management for martens 
(see Factor A; Zielinski et al. 2001, pp. 483-488).
    The petition also states that existing regulatory mechanisms on 
Federal Forest Service lands are not adequate to protect Humboldt 
martens from habitat loss and degradation due to timber harvesting (CBD 
and EPIC 2010, pp. 28-29). The petition acknowledges that the American 
marten is recognized as a Forest Service sensitive species in 
California, but not in Oregon (CBD and EPIC 2010, p. 29); however, the 
petition goes on to state that the sensitive species status in 
California does not provide nondiscretionary protections and thus is 
not considered an adequate regulatory mechanism (CBD and EPIC 2010, p. 
29). The petition also states that large areas of the Humboldt marten's 
current range on Forest Service lands are designated as matrix lands 
under the Northwest Forest Plan (NWFP), and that timber harvesting that 
may be incompatible with Humboldt marten habitat management is allowed 
on matrix lands (CBD and EPIC 2010, pp. 29-30). The NWFP was adopted in 
1994 to guide the management of 37,500 sq mi (97,125 sq km) of Federal 
lands in portions of western Washington and Oregon, and northwestern 
California. Implementation of the NWFP was intended to provide, over 
time, a network of large blocks of late-successional forest habitat 
connected by riparian reserves. However, even with NWFP implementation, 
timber harvest, fuels reduction projects, and road construction may 
continue to result in the loss and fragmentation of occupied and 
suitable but unoccupied Humboldt marten habitat throughout a 
substantial portion of its range in coastal Oregon and northwestern 
California. Protections for late-successional forest habitats provided 
for species such as the northern spotted owl (Strix occidentalis 
caurina) and marbled murrelet (Brachyramphus marmoratus), which are 
listed as threatened under the Act, provide certain protections for 
marten habitat but may not provide sufficient protections for certain 
habitat elements known to be important for Humboldt martens, such as 
shade-tolerant shrub cover.
Summary of Factor D
    In summary, we find that the information provided in the petition, 
as well as other information readily available in our files, presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted due to the inadequacy of existing 
regulatory mechanisms that address habitat threats associated with 
timber harvesting and forest management. We will review the possible 
effects of these threats on Humboldt marten more thoroughly in our 
status review.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The petition states that several other factors threaten the 
continued existence of the Humboldt marten, including small population 
size effects; mortality from vehicle strikes, poisoning, and 
starvation; and global climate change (CBD and EPIC 2010, pp. 27-28).
    The petition states that widespread timber harvesting has resulted 
in drastically reduced suitable habitat for Humboldt marten, and that 
existing populations in California and coastal Oregon are small and 
isolated (CBD and EPIC 2010, p. 27). The smaller a population becomes, 
the more susceptible it is to stochastic (random) demographic and 
environmental variation and to genetic factors that tend to reduce 
population size even more and that may push the population to 
extinction (Primack 1993, p. 274). Primack (1993, p. 335) found that 
population size was the best predictor of extinction probability. 
Slauson et al. (2009b, p. 5) used multi-season occupancy modeling to 
estimate the probability of extinction and colonization (probability 
that Humboldt martens in northwestern California would reoccupy 
currently unoccupied suitable habitat) and found that the probability 
of extinction was higher than the probability of colonization (Slauson 
et al. 2009b, p. 10). As mentioned in the Species Information section, 
for a mammal of its size, American martens--and presumably Humboldt 
martens--have a relatively low reproductive rate, suggesting a slow 
recovery from population-level impacts. Species with low rates of 
population increase are often unable to rebuild their populations fast 
enough to avoid extinction following habitat loss (Primack 1993, p. 
102). As mentioned in the Population Status section, it is estimated 
that the extant Humboldt marten population in coastal northern 
California contains fewer than 100 individuals and is believed to be 
declining, and the two coastal Oregon populations are also considered 
to be small and in decline. Information in our files supports the 
assertion in the petition that current Humboldt marten populations in 
coastal northern California and coastal Oregon are vulnerable to 
extinction processes due to small and isolated populations (Slauson et 
al. 2007, p. 458; Slauson et al. 2009b, p. 13).
    The petition states that the Humboldt marten is threatened by 
several sources of mortality including vehicle strikes, poisoning, and 
starvation (CBD and EPIC 2010, p. 28). Zielinski et al. (2001, p. 484) 
noted that 10 marten road kills had been reported from coastal central 
Oregon between 1980 and 1998, while no marten road kills had been 
reported in coastal California. We acknowledge that Humboldt martens 
are occasionally killed by vehicles along highways, but we do not 
consider the numbers reported by Zielinski et al. (2001, p.

[[Page 1908]]

484) to be sufficiently great to threaten the continued existence of 
the Humboldt marten, nor do we have information in our files indicating 
that mortality from vehicle collisions threatens martens in coastal 
northern California and coastal Oregon. The petition also states that 
martens are vulnerable to mortality from starvation and poisoning, 
although the petition acknowledges that the extent of the threat of 
these factors to the Humboldt marten has not been quantified (CBD and 
EPIC 2010, p. 28). We conclude that information in the petition and in 
our files does not indicate that mortality from poisoning or starvation 
threatens the continued existence of martens in coastal northern 
California and coastal Oregon. However, we will evaluate these 
potential threats more thoroughly in our 12-month finding.
    The petition further states that global climate change threatens 
the Humboldt marten (CBD and EPIC 2010, p. 28). According to the 
petition, vegetation changes resulting from climate change could cause 
changes in the type and availability of prey for martens and could 
affect availability of resting and denning sites, shrub cover, and 
canopy cover. The petition also states that climate change could lead 
to tree mortality from insect infestation, disease, and drought. While 
we acknowledge that climate change will result in a variety of 
environmental changes including changes in vegetation composition and 
structure, information presented in the petition is too general and 
speculative to determine whether climate change effects may threaten 
the continued existence of the Humboldt marten, and we do not have 
specific information available in our files indicating that climate 
change threatens the continued existence of the Humboldt marten.
Summary of Factor E
    In summary, we find that the information provided in the petition, 
as well as other information readily available in our files, presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted due to other natural or manmade 
factors affecting its continued existence, specifically small 
population effects. We will review threats posed by small population 
effects more thoroughly during our status review.

Finding

    On the basis of our determination under section 4(b)(3)(A) of the 
Act, we determine that the petition presents substantial scientific or 
commercial information indicating that listing the Humboldt marten 
throughout all or a significant portion of its range may be warranted. 
This finding is based on substantial information provided in the 
petition and in our files for Factor A, Factor C, Factor D, and Factor 
E. We determine that the information provided under Factor B is not 
substantial.
    Because we have found that the petition presents substantial 
information indicating that listing the Humboldt marten may be 
warranted, we are initiating a status review to determine whether 
listing the Humboldt marten under the Act is warranted. Because ongoing 
genetics research may result in changes to American marten taxonomy, we 
will examine whether the purported subspecific designation of Humboldt 
marten is appropriate during our status review. If the Humboldt marten 
does not maintain its status as a subspecies, we will examine during 
our status review whether the Humboldt marten meets criteria for 
designation as a distinct population segment under our February 7, 
1996, DPS policy (61 FR 4722).
    The ``substantial information'' standard for a 90-day finding 
differs from the Act's ``best scientific and commercial data'' standard 
that applies to a status review to determine whether a petitioned 
action is warranted. A 90-day finding does not constitute a status 
review under the Act. In a 12-month finding, we will determine whether 
a petitioned action is warranted after we have completed a thorough 
status review of the species, which is conducted following a 
substantial 90-day finding. Because the Act's standards for 90-day and 
12-month findings are different, as described above, a substantial 90-
day finding does not mean that the 12-month finding will result in a 
warranted finding.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Arcata Fish and 
Wildlife Office (see FOR FURTHER INFORMATION CONTACT section).

Authors

    The primary authors of this document are the staff members of the 
Arcata Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT 
section).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: December 30, 2011.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-479 Filed 1-11-12; 8:45 am]
BILLING CODE 4310-55-P