Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the Contiguous United States Distinct Population Segment of the Canada Lynx, 68294-68328 [05-22193]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 70, Number 216 (Wednesday, November 9, 2005)]
[Proposed Rules]
[Pages 68294-68328]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-22193]



[[Page 68293]]

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

Part V





Department of the Interior





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



Fish and Wildlife Service



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



50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Proposed Designation of 
Critical Habitat for the Contiguous United States Distinct Population 
Segment of the Canada Lynx; Proposed Rule

Federal Register / Vol. 70, No. 216 / Wednesday, November 9, 2005 / 
Proposed Rules

[[Page 68294]]


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

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU52


Endangered and Threatened Wildlife and Plants; Proposed 
Designation of Critical Habitat for the Contiguous United States 
Distinct Population Segment of the Canada Lynx

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
designate critical habitat for the contiguous United States distinct 
population segment of the Canada lynx (Lynx canadensis) (lynx) pursuant 
to the Endangered Species Act of 1973, as amended (Act). The lynx 
generally inhabits cold, moist boreal forests in the contiguous United 
States. In total, approximately 26,935 square miles (mi\2\) (69,760 
square kilometers (km\2\)) fall within the boundaries of the proposed 
critical habitat designation, in four units in the States of Idaho, 
Maine, Minnesota, Montana, and Washington. However, we are not 
proposing to designate all of the area with the boundaries. In 
particular, we are not including lands within Lynx Analysis Units in 
the Superior National Forest in Minnesota, because they do not meet the 
definition of critical habitat pursuant to section 3(5)(A) of the Act 
as a consequence of the Superior National Forest having amended its 
Forest Plan to adopt the Lynx Conservation Assessment and Strategy. 
These lands are not included in the estimated square miles of the 
proposed designation. In addition, we are not proposing to designate 
critical habitat on the Federal lands within seven National Forests in 
Idaho, Montana, and Washington that are covered by the May 2005 
Conservation Agreement and therefore do not meet the definition of 
critical habitat. These lands, however, are included in the estimated 
square miles of the proposed designation owing to difficulties in 
obtaining accurate estimates of the area of Federal land within each 
national forest boundary in a timely manner. This will be corrected in 
the final designation.
    We hereby solicit data and comments from the public on all aspects 
of this proposal, including data on economic and other potential 
impacts of the designation. We are also soliciting public comments on 
inclusion of certain lands in the designation and on the 
appropriateness of excluding lands from this designation that are 
covered by management plans that provide for the conservation of lynx 
and our determination as to whether existing management plans provide 
special management and protection for lynx habitat. In addition, 
depending on public comment and our analysis at the time of the final 
designation, any or all of these Forest Service lands described above 
may be included in the final designation, and we are specifically 
seeking comment on whether these lands are covered by the definition of 
critical habitat and should be included in the final designation.
    In the development of our final designation, we will incorporate or 
address any new information received during the public comment period, 
or from our evaluation of the potential economic impacts of this 
proposal. We may revise this proposal to address new information, to 
exclude areas that may warrant exclusion pursuant to section 4(b)(2) of 
the Act, or to add in those areas determined to be essential to 
conservation of the species, but not included in this proposal.

DATES: We will accept comments from all interested parties until 
February 7, 2006. We will hold public hearings and informational 
sessions on the following dates: December 7, 2005, (Minnesota); 
December 14, 2005, (Maine); January 10, 2006, (Montana); and January 
18, 2006, (Washington) (see SUPPLEMENTARY INFORMATION section, below, 
for locations and times).

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may submit written comments and information by mail or hand-
delivery to Field Supervisor, U.S. Fish and Wildlife Service, Montana 
Ecological Services Office, 100 N. Park Avenue, Suite 320, Helena, 
Montana 59601.
    2. You may submit oral and/or written comments and information at 
the public hearings (see SUPPLEMENTARY INFORMATION, below, for 
locations and times).
    3. You may send comments by electronic mail (e-mail) to fw6_
lynx@fws.gov. Please see the Public Comments Solicited section below 
for file format and other information about electronic filing.
    4. You may fax your comments to Field Supervisor, U.S. Fish and 
Wildlife Service, Montana Ecological Services Office at 406-449-5339.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Montana Ecological Services Office at the above address.

FOR FURTHER INFORMATION CONTACT: Lori Nordstrom, Montana Ecological 
Services Office (address above), telephone 406-449-5225; facsimile 406-
449-5339.

SUPPLEMENTARY INFORMATION: Public hearings and informational sessions 
on this proposal will be held in the following locations:

Maine

    Wednesday, December 14, 2005, from 8 to 9 p.m. at the Black Bear 
Inn and Conference Center, 4 Godfrey Drive, Orono, Maine. The hearing 
will be preceded by an informational session from 7 to 8 p.m.

Minnesota

    Wednesday, December 7, 2005, from 7:30 to 9 p.m. at The Inn on Lake 
Superior, 350 Canal Park Drive, Duluth, Minnesota. The hearing will be 
preceded by an informational session from 6 to 7:30 p.m.

Montana

    Tuesday, January 10, 2006, from 6 to 8 p.m. at Westcoast Kalispell 
Center, 20 North Main Street, Kalispell, Montana. The hearing will be 
preceded by an informational session from 4:30 to 6 p.m.

Washington

    Wednesday, January 18, 2006, from 7 to 8:30 p.m. at Methow Valley 
Community Center, 201 South Methow Valley, Hwy 20, Twisp, Washington. 
The hearing will be preceded by an informational session from 5 to 6:30 
p.m.

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Maps of the 
proposed critical habitat are available for viewing by appointment 
during regular business hours at (1) The Montana Ecological Services 
Office (see ADDRESSES); (2) the Service offices identified in the 
Section 7 Consultation section below (Maine Field Office (Old Town, 
ME), Twin Cities Field Office (Bloomington, MN), and the Upper Columbia 
River Basin Office (Spokane, WA)); or (3) the Internet at https://

[[Page 68295]]

mountain-prairie.fws.gov/species/ mammals/lynx/.
    On the basis of public comment, during the development of the final 
rule we may find, among other things, that areas proposed are not 
essential to the conservation of the species or do not require special 
management considerations or protection, are appropriate for exclusion 
under section 4(b)(2) of the Act, or are not appropriate for exclusion, 
and in all of these cases, this information will be incorporated into 
the final designation. Final management plans and data supporting their 
effectiveness that address the conservation of the lynx must be 
submitted to us during the public comment period so that we can take 
them into consideration when making our final critical habitat 
determination.

Comments Are Invited Specifically Concerning

    (1) The reasons any habitat should or should not be determined to 
be critical habitat as provided by section 4 of the Act, including, but 
not limited to, whether the benefit of designation will outweigh any 
threats to the species due to designation;
    (2) Specific information on the amount and distribution of lynx 
habitat in the contiguous United States, and what occupied habitat has 
features that are essential to the conservation of the species and why 
and what unoccupied habitat is essential to the conservation of the 
species and why;
    (3) Comments or information that may assist us with identifying or 
clarifying the Primary Constituent Elements (PCEs);
    (4) Land use designations and current or planned activities in 
areas proposed as critical habitat and their possible impacts on 
proposed critical habitat;
    (5) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed designation and, in particular, any 
impacts on small entities;
    (6) As discussed in this proposed rule, we are considering whether 
some of the lands we have identified as having features essential for 
the conservation of the lynx should not be included in the final 
designation of critical habitat if, prior to the final critical habitat 
designation, they are covered by final management plans that 
incorporate the conservation measures for the lynx (i.e., the Lynx 
Conservation Assessment and Strategy (LCAS) (Ruediger et al. 2000), or 
comparable). In particular, seven National Forests and one Bureau of 
Land Management (BLM) district are in the process of revising or 
amending their Land and Resource Management Plans (LRMP) to provide 
measures for lynx conservation. It is anticipated that all of these 
plans will be complete prior to promulgation of the final critical 
habitat designation. As a result, all National Forest and BLM plans 
would have measures that provide for conservation of lynx, and 
consequently will not be in need of special management or protection.
    Currently, National Forests that have not revised or amended their 
LRMPs operate under a Conservation Agreement with the Service in which 
the parties agree to take measures to reduce or eliminate adverse 
effects or risks to lynx and its occupied habitat pending amendments to 
LRMPs. The LCAS is a basis for implementing this Agreement.
    In addition, we will be evaluating the adequacy of existing 
management plans to conserve lynx on lands that are designated 
wilderness areas or National Parks, as discussed in this proposed rule.
    We specifically solicit comment on whether such areas meet the 
definition of critical habitat based on:
    (A) Whether these areas contain features essential to the 
conservation of the lynx;
    (B) The adequacy of these management plans or the Conservation 
Agreement to provide special management and protection to lynx habitat;
    Any of these lands identified above may, if appropriate, be 
included in the final critical habitat designation, even if not 
proposed for designation in this notice.
    (7) Our proposal to not include tribal lands in the Maine and 
Minnesota units under the Secretarial Order Number 3206. The size of 
the individual reservation lands in the Maine and Minnesota units is 
relatively small. As a result, we believe conservation of the lynx can 
be achieved by limiting the designation to the other lands in the 
proposed units (see ``Relationship of Critical Habitat to Tribal 
Lands'' below).
    (8) Whether lands in three areas are essential for the conservation 
of the species and the basis for why they might be essential. These 
areas are: (a) The Greater Yellowstone Ecosystem (Wyoming, Montana, and 
Idaho); (b) the ``Kettle Range'' in Ferry County, Washington; and (c) 
the Southern Rocky Mountains.
    (9) How the proposed boundaries of critical habitat units could be 
refined to more closely conform to the boreal forest types occupied by 
lynx. Maps that accurately depict the specific vegetation types on all 
land ownerships were not readily available. Additionally, even if 
accurate, detailed vegetation maps were available, we were unsure how 
to delineate and describe critical habitat boundaries that solely 
encompassed lands containing the features essential to the conservation 
of the lynx.
    (10) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    If you wish to comment, you may submit your comments and materials 
concerning this proposal by any one of several methods (see ADDRESSES 
section). Please submit Internet comments to fw6_lynx@fws.gov in ASCII 
file format and avoid the use of special characters or any form of 
encryption. Please also include ``Attn: lynx comments'' in your e-mail 
subject header and your name and return address in the body of your 
message. If you do not receive a confirmation from the system that we 
have received your Internet message, contact us directly by calling our 
Montana Ecological Services Office at telephone number 406-449-5225.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Individual respondents may request that we withhold 
their home addresses from the rulemaking record, which we will honor to 
the extent allowable by law. There also may be circumstances in which 
we would withhold from the rulemaking record a respondent's identity, 
as allowable by law. If you wish us to withhold your name and/or 
address, you must state this prominently at the beginning of your 
comment. However, we will not consider anonymous comments. We will make 
all submissions from organizations or businesses, and from individuals 
identifying themselves as representatives or officials of organizations 
or businesses, available for public inspection in their entirety. 
Comments and materials received will be available for public 
inspection, by appointment, during normal business hours at the above 
address.

Designation of Critical Habitat Provides Little Additional Protection 
to Species

    In 30 years of implementing the Act, the Service has found that the 
designation of statutory critical habitat provides little additional 
protection to most listed species, while consuming significant amounts 
of available conservation resources. The Service's present system for 
designating critical

[[Page 68296]]

habitat has evolved since its original statutory prescription into a 
process that provides little real conservation benefit, is driven by 
litigation and the courts rather than biology, limits our ability to 
fully evaluate the science involved, consumes enormous agency 
resources, and imposes huge social and economic costs). The Service 
believes that additional agency discretion would allow our focus to 
return to those actions that provide the greatest benefit to the 
species most in need of protection.

Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Endangered Species Act

    While attention to and protection of habitat is paramount to 
successful conservation actions, we have consistently found that, in 
most circumstances, the designation of critical habitat is of little 
additional value for most listed species, yet it consumes large amounts 
of conservation resources. Sidle (1987) stated, ``Because the Act can 
protect species with and without critical habitat designation, critical 
habitat designation may be redundant to the other consultation 
requirements of section 7.'' Currently, only 466 species or 35 percent 
of the 1,268 listed species in the United States under the jurisdiction 
of the Service have designated critical habitat.
    We address the habitat needs of all 1,268 listed species through 
conservation mechanisms such as listing, section 7 consultations, the 
section 4 recovery planning process, the section 9 protective 
prohibitions of unauthorized take, section 6 funding to the States, and 
the section 10 incidental take permit process. The Service believes 
that it is these measures that may make the difference between 
extinction and survival for many species.
    We note, however, that the August 6, 2004, Ninth Circuit judicial 
opinion, (Gifford Pinchot Task Force v. United States Fish and Wildlife 
Service) found our definition of adverse modification invalid. In 
response to the decision, the Director has provided guidance to the 
Service based on the statutory language. In this rule, our analysis of 
the consequences and relative costs and benefits of the critical 
habitat designation is based on application of the statute consistent 
with the 9th Circuit's ruling and the Director's guidance.

Procedural and Resource Difficulties in Designating Critical Habitat

    We have been inundated with lawsuits for our failure to designate 
critical habitat, and we face a growing number of lawsuits challenging 
critical habitat determinations once they are made. These lawsuits have 
subjected the Service to an ever-increasing series of court orders and 
court-approved settlement agreements, compliance with which now 
consumes nearly the entire listing program budget. This leaves the 
Service with little ability to prioritize its activities to direct 
scarce listing resources to the listing program actions with the most 
biologically urgent species conservation needs.
    The consequence of the critical habitat litigation activity is that 
limited listing funds are used to defend active lawsuits, to respond to 
Notices of Intent to sue relative to critical habitat, and to comply 
with the growing number of adverse court orders. As a result, listing 
petition responses, the Service's own proposals to list critically 
imperiled species, and final listing determinations on existing 
proposals are all significantly delayed.
    The accelerated schedules of court ordered designations have left 
the Service with almost no ability to provide for adequate public 
participation or to ensure a defect-free rulemaking process before 
making decisions on listing and critical habitat proposals due to the 
risks associated with noncompliance with judicially-imposed deadlines. 
This in turn fosters a second round of litigation in which those who 
fear adverse impacts from critical habitat designations challenge those 
designations. The cycle of litigation appears endless, is very 
expensive, and in the final analysis provides relatively little 
additional protection to listed species.
    The costs resulting from the designation include legal costs, the 
cost of preparation and publication of the designation, the analysis of 
the economic effects and the cost of requesting and responding to 
public comment, and in some cases the costs of compliance with the 
National Environmental Policy Act (NEPA). None of these costs result in 
any benefit to the species that is not already afforded by the 
protections of the Act enumerated earlier, and they directly reduce the 
funds available for direct and tangible conservation actions.

Background

    It is our intent to discuss only those topics directly relevant to 
the designation of critical habitat in this proposed rule. For more 
information on the lynx, refer to the final listing rule published in 
the Federal Register on March 24, 2000 (65 FR 16052), and the 
clarification of findings published in the Federal Register on July 3, 
2003 (68 FR 40076).
    Canada lynx are medium-sized cats, generally measuring 75 to 90 
centimeters (cm) (30 to 35 inches (in)) long and weighing 8 to10.5 
kilograms (18 to 23 pounds) (Quinn and Parker 1987). They have large, 
well-furred feet and long legs for traversing snow; tufts on the ears; 
and short, black-tipped tails.
    Lynx are highly specialized predators of snowshoe hare (Lepus 
americanus) (McCord and Cardoza 1982; Quinn and Parker 1987; Aubry et 
al. 2000). Lynx and snowshoe hares are strongly associated with what is 
broadly described as boreal forest (Bittner and Rongstad 1982; McCord 
and Cardoza 1982; Quinn and Parker 1987; Agee 2000; Aubry et al. 2000; 
Hodges 2000a, b; McKelvey et al. 2000b). The predominant vegetation of 
boreal forest is conifer trees, primarily species of spruce (Picea 
spp.) and fir (Abies spp.) (Elliot-Fisk 1988). In the contiguous United 
States, the boreal forest types transition to deciduous temperate 
forest in the Northeast and Great Lakes, and to subalpine forest in the 
West (Agee 2000). Lynx habitat can generally be described as moist 
boreal forests that have cold, snowy winters and a snowshoe hare prey 
base (Quinn and Parker 1987; Agee 2000; Aubry et al. 2000; Buskirk et 
al. 2000b; Ruggiero et al. 2000).
    Snow conditions also determine the distribution of lynx (Ruggiero 
et al. 2000). Lynx are morphologically and physiologically adapted for 
hunting snowshoe hares and surviving in areas that have cold winters 
with deep, fluffy snow for extended periods. These adaptations provide 
lynx a competitive advantage over potential competitors, such as 
bobcats (Lynx rufus) or coyotes (Canis latrans) (McCord and Cardoza 
1982; Buskirk et al 2000a; Ruediger et al. 2000; Ruggiero et al. 2000). 
Bobcats and coyotes have a higher foot load (more weight per surface 
area of foot), which causes them to sink into the snow more than lynx. 
Therefore, bobcats and coyotes cannot efficiently hunt in fluffy or 
deep snow and are at a competitive disadvantage to lynx. Long-term snow 
conditions presumably limit the winter distribution of potential lynx 
competitors such as bobcats (McCord and Cardoza 1982) or coyotes.
    Because of the patchiness and temporal nature of high-quality 
snowshoe hare habitat, lynx populations

[[Page 68297]]

require large boreal forest landscapes to ensure that sufficient high-
quality snowshoe hare habitat is available at any point in time and to 
ensure that lynx may move freely among patches of suitable habitat and 
among subpopulations of lynx. Populations that are composed of a number 
of discrete subpopulations, connected by dispersal, are called 
metapopulations (McKelvey et al. 2000c). Individual lynx maintain large 
home ranges (reported as generally ranging between 31-216 
km2 [12-83 mi2]) (Koehler 1990; Aubry et al. 
2000; Squires and Laurion 2000; Squires et al. 2004b; Vashon et al. 
2005a). The size of lynx home ranges varies depending on the abundance 
of prey, the animal's gender and age, season, and the density of the 
lynx population (Koehler 1990; Poole 1994; Slough and Mowat 1996; Aubry 
et al. 2000; Mowat et al. 2000; Vashon et al. 2005a). When densities of 
snowshoe hares decline, for example, lynx enlarge their home ranges to 
obtain sufficient amounts of food to survive and reproduce.
    In the contiguous United States, the boreal forest landscape is 
naturally patchy and transitional because it is the southern edge of 
the boreal forest range. This generally limits snowshoe hare 
populations in the contiguous United States from achieving densities 
similar to those of the expansive northern boreal forest in Canada 
(Wolff 1980; Buehler and Keith 1982; Koehler 1990; Koehler and Aubry 
1994). Additionally, the presence of more snowshoe hare predators and 
competitors at southern latitudes may inhibit the potential for high-
density hare populations (Wolff 1980). As a result, lynx generally 
occur at relatively low densities in the contiguous United States as 
compared to the high lynx densities in the northern boreal forest of 
Canada (Aubry et al. 2000) or the densities of a species such as the 
bobcat, which is a habitat and prey generalist.
    Lynx are highly mobile; long-distance movements (greater than 100 
km (60 mi)) are characteristic (Aubry et al. 2000; Mowat et al. 2000). 
Lynx disperse primarily when snowshoe hare populations decline (Ward 
and Krebs 1985; O'Donoghue et al. 1997; Poole 1997). Subadult lynx also 
disperse even when prey is abundant (Poole 1997), presumably to 
establish new home ranges. Lynx also make exploratory movements outside 
their home ranges (Aubry et al. 2000; Squires et al. 2001).
    The boreal forest landscape is naturally dynamic. Forest stands 
within the landscape change as they undergo succession after natural or 
human-caused disturbances such as fire, insect epidemics, wind, ice, 
disease, and forest management (Elliot-Fisk 1988, Agee 2000). As a 
result, lynx habitat within the boreal forest landscape is typically 
patchy because the boreal forest contains stands of differing ages and 
conditions, only some of which are suitable as lynx foraging or denning 
habitat at any point in time (McKelvey et al. 2000a; Hoving et al. 
2004).
    Snowshoe hares comprise a majority of the lynx diet (Nellis et al. 
1972; Brand et al. 1976; Koehler 1990; Apps 2000; Aubry et al. 2000; 
Mowat et al. 2000; von Kienast 2003; Squires et al. 2004b). When 
snowshoe hare populations are low, female lynx produce few or no 
kittens that survive to independence (Nellis et al. 1972; Brand et al. 
1976; Brand and Keith 1979; Poole 1994; Slough and Mowat 1996; 
O'Donoghue et al. 1997, Aubry et al. 2000; Mowat et al. 2000). Lynx 
prey opportunistically on other small mammals and birds, particularly 
during lows in the snowshoe hare population, but alternate prey species 
may not sufficiently compensate for low availability of snowshoe hares, 
resulting in reduced lynx populations (Brand et al. 1976; Brand and 
Keith 1979; Koehler 1990; Mowat et al. 2000).
    In northern Canada, lynx populations fluctuate in response to the 
cycling of snowshoe hare populations (Hodges 2000a; Mowat et al. 2000). 
Although snowshoe hare populations in the northern portion of their 
range show strong, regular population cycles, these fluctuations are 
generally much less pronounced in the southern portion of the range in 
the contiguous United States (Hodges 2000b). In the contiguous United 
States, the degree to which regional local lynx population fluctuations 
are influenced by local snowshoe hare population dynamics is unclear. 
However, it is anticipated that because of natural fluctuations in 
snowshoe hare populations, there will be periods when lynx densities 
are extremely low.
    Because lynx population dynamics, survival and recruitment are 
closely tied to snowshoe hare availability, snowshoe hare habitat is a 
component of lynx habitat. Lynx generally concentrate their foraging 
and hunting activities in areas where snowshoe hare populations are 
high (Koehler et al. 1979; Ward and Krebs 1985; Murray et al. 1994; 
O'Donoghue et al. 1997, 1998). Snowshoe hares are most abundant in 
forests with dense understories that provide forage, cover to escape 
from predators, and protection during extreme weather (Wolfe et al. 
1982; Litvaitis et al. 1985; Hodges 2000a, b). Generally, hare 
densities are higher in regenerating, earlier successional forest 
stages because they have greater understory structure than mature 
forests (Buehler and Keith 1982; Wolfe et al. 1982; Koehler 1990; 
Hodges 2000b; Homyack 2003; Griffin 2004). However, snowshoe hares can 
be abundant in mature forests with dense understories (Griffin 2004).
    Within the boreal forest, lynx den sites are located where coarse 
woody debris, such as downed logs and windfalls, provides security and 
thermal cover for lynx kittens (McCord and Cardoza 1982; Koehler 1990; 
Slough 1999; Squires and Laurion 2000; J. Organ, Service, in litt. 
2001). The amount of structure (e.g., downed, large woody debris) 
appears to be more important than the age of the forest stand for lynx 
denning habitat (Mowat et al. 2000).

Previous Federal Actions

    For more information on previous Federal actions concerning the 
lynx, refer to the final listing rule published in the Federal Register 
on March 24, 2000 (65 FR 16052), and the clarification of findings 
published in the Federal Register on July 3, 2003 (68 FR 40076). As a 
result of litigation from Defenders of Wildlife, et al., the U.S. 
District Court for the District of Columbia instructed us to propose 
critical habitat by November 1, 2005, and to issue a final rule for 
critical habitat by November 1, 2006. This proposal has been completed 
in compliance with the Court order.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a species at the time it is listed, upon 
a determination that such areas are essential for the conservation of 
the species. ``Conservation'' means the use of all methods and 
procedures that are necessary to bring an endangered or a threatened 
species to the point at which listing under the Act is no longer 
necessary.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against destruction or adverse modification of 
critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 of the Act requires 
consultation on Federal actions that are

[[Page 68298]]

likely to result in the destruction or adverse modification of critical 
habitat. The designation of critical habitat does not affect land 
ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow government or 
public access to private lands.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species at the time of listing must 
first have features that are ``essential to the conservation of the 
species.'' Critical habitat designations identify, to the extent known 
using the best scientific data available, habitat areas that provide 
essential life cycle needs of the species (i.e., areas on which are 
found the primary constituent element, as defined at 50 CFR 424.12(b)).
    Habitat occupied at the time of listing may be included in critical 
habitat only if the essential features thereon may require special 
management or protection. Thus, we do not include areas where existing 
management is sufficient to conserve the species. (As discussed below, 
such areas may also be excluded from critical habitat pursuant to 
section 4(b)(2).) Accordingly, when the best available scientific data 
do not demonstrate that the conservation needs of the species so 
require, we will not designate critical habitat in areas outside the 
geographic area occupied by the species at the time of listing.
    The Service's Policy on Information Standards Under the Endangered 
Species Act, published in the Federal Register on July 1, 1994 (59 FR 
34271), and Section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) 
and the associated Information Quality Guidelines issued by the 
Service, provide criteria, establish procedures, and provide guidance 
to ensure that decisions made by the Service represent the best 
scientific and commercial data available. They require Service 
biologists to the extent consistent with the Act and with the use of 
the best scientific and commercial data available, to use primary and 
original sources of information as the basis for recommendations to 
designate critical habitat. When determining which areas are critical 
habitat, a primary source of information is generally the listing 
package for the species. Additional information sources include the 
recovery plan for the species, articles in peer-reviewed journals, 
conservation plans developed by States and counties, scientific status 
surveys and studies, biological assessments, or other unpublished 
materials and expert opinion or personal knowledge. All information is 
used in accordance with the provisions of Section 515 of the Treasury 
and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658) and the associated Information Quality Guidelines 
issued by the Service.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Habitat is often 
dynamic, and species may move from one area to another over time. 
Furthermore, we recognize that designation of critical habitat may not 
include all of the habitat areas that may eventually be determined to 
be necessary for the recovery of the species. For these reasons, 
critical habitat designations do not signal that habitat outside the 
designation is unimportant or may not be required for recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the action. Federally funded or permitted projects 
affecting listed species outside their designated critical habitat 
areas may still result in jeopardy findings in some cases. Similarly, 
critical habitat designations made on the basis of the best scientific 
information available at the time of designation will not control the 
direction and substance of future recovery plans, habitat conservation 
plans, or other species conservation planning efforts if new 
information available to these planning efforts calls for a different 
outcome.

Methods

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available in determining critical habitat. We have 
reviewed the approach to the conservation of the lynx provided in a 
recovery outline (Service 2005); information from State, Federal and 
Tribal agencies; and information from academia and private 
organizations that have collected scientific data on lynx.
    The Service recently completed a recovery outline for the lynx 
(Service 2005). Recovery outlines are brief, internally-developed 
documents intended as preliminary strategies for conservation of listed 
species until a formal recovery plan is completed (F. Dunkle, USFWS, in 
litt. 1989). Development of a formal recovery plan for lynx has not yet 
begun. The lynx recovery outline was prepared by Service staff 
experienced in lynx conservation and/or recovery planning under the Act 
and two lynx experts from the U.S. Forest Service (USFS). The lynx 
recovery outline presents current understandings of historical and 
current lynx distribution, ecology, and population dynamics. The 
outline introduces concepts regarding the relative importance of 
different geographic areas to the persistence of lynx in the contiguous 
United States, identifying areas as either core, provisional core, 
secondary or peripheral based on lynx records over time and evidence of 
reproduction. Additionally, the outline describes preliminary recovery 
objectives and actions.
    We also reviewed available information that pertains to the habitat 
requirements of this species and its principal prey, the snowshoe hare. 
This included data in reports submitted by researchers holding recovery 
permits under section 10(a)(1)(A) of the Act; research published in 
peer-reviewed articles, presented in academic theses, agency reports 
and unpublished data; and various Geographic Information System (GIS) 
coverages (e.g., land cover type information, land ownership 
information, snow depth information, topographic information, locations 
of lynx obtained from radio- or GPS-collars and locations of lynx 
confirmed via DNA analysis or other verified records).
    In evaluating areas to propose as critical habitat we first 
determined the geographic area occupied by the species. We utilized 
data providing verified evidence of the occurrence of lynx and evidence 
of the presence of breeding lynx populations as represented by records 
of lynx reproduction. We utilized records since 1995 to ensure that 
this proposed critical habitat designation is based on the data that 
most closely represents the current status of lynx in the contiguous 
United States and the geographic area occupied by the species. Data 
that define the historic and current range of the lynx (e.g., McKelvey 
et al. 2000b; Hoving et al. 2003) constitute the geographic area that 
may be occupied by the species; therefore, we determined that areas 
outside the historic distribution are not essential to the conservation 
of the species. Although the average life span of a wild lynx is not 
known, we have assumed that a lynx born in 1995 could have been alive 
in 2000 or 2003, the dates of publication of the final listing rule and 
the clarification of findings. Furthermore, lynx-related research in 
the contiguous United States substantially increased after the 1998 
proposal to list, providing additional

[[Page 68299]]

information on which to base this proposed critical habitat 
designation. These recent verified records were provided by Federal 
research entities, state wildlife agencies, academic researchers, and 
private individuals or organizations working on lynx (K. Aubry, Pacific 
Northwest Research Station, unpubl. data; S. Gehman, Wildthings 
Unlimited, unpubl. data; S. Gniadek, Glacier National Park, unpubl. 
data; S. Loch, Independent Scientist, and E. Lindquist, Superior 
National Forest, unpubl. data; K. McKelvey, Rocky Mountain Research 
Station; unpubl. data; Minnesota Department of Natural Resources 2005; 
R. Moen, University of Minnesota, Natural Resources Research Institute, 
unpubl. data.; J. Squires, Rocky Mountain Research Station, unpubl. 
data; J. Vashon, Maine Department of Inland Fisheries and Wildlife, 
unpubl. data).
    By accepting only verified recent lynx records, we restricted the 
available lynx occurrence dataset because we wanted reliable data for 
the purposes of evaluating areas and features for critical habitat 
designation. The reliability of lynx occurrence reports can be 
questionable because the bobcat, a common species, can be confused with 
the lynx, which is similar in appearance. Additionally, many surveys 
are conducted by snow tracking in which correct identification of 
tracks can be difficult because of variable conditions affecting the 
quality of the track and variable expertise of the tracker. Our 
definition of a verified lynx record is modified from McKelvey et al. 
(2000b)--(1) An animal (live or dead) in hand or observed closely by a 
person knowledgeable in lynx identification, (2) genetic (DNA) 
confirmation, (3) snow tracks only when confirmed by genetic analysis 
(see for example Murphy et al. 2004; McKelvey et al. in press) or (4) 
location data from radio- or GPS-collared lynx. Documentation of lynx 
reproduction consists of lynx kittens in hand, or observed with the 
mother by someone knowledgeable in lynx identification, or snow tracks 
demonstrating family groups traveling together, as identified by a 
person highly knowledgeable in identification of carnivore tracks.
    The geographical area occupied by the species was then delineated 
to encompass areas containing features essential to the conservation of 
the lynx, the majority of recent lynx records, evidence of breeding 
lynx populations, the boreal forest type that is currently occupied by 
lynx in that particular region and direct connectivity with lynx 
populations in Canada. Lynx populations in the contiguous United States 
seem to be influenced by lynx population dynamics in Canada (Thiel 
1987; McKelvey et al. 2000a, c). Many of these populations in Canada 
are directly interconnected with United States populations, and are 
likely a source of emigration into contiguous United States lynx 
populations. Therefore, we assume that retaining connectivity with 
larger lynx populations in Canada is important to ensuring long-term 
persistence of lynx populations in the United States. We assume that, 
regionally, lynx within the contiguous United States and adjacent 
Canadian provinces interact as metapopulations. Where available, data 
on historic average snow depths and bobcat harvest provided additional 
insight for refining and delineating appropriate boundaries. In Maine 
and Minnesota, we used the international border with Canada and roads 
or township lines where possible for ease in description and clarity. 
In the North Cascades and Northern Rockies, the features essential to 
the conservation of lynx, the majority of lynx records, evidence of 
reproduction, and the boreal forest types are found above 4,000 feet 
(ft) (1,219 meters [m]) in elevation (McKelvey et al. 2000b; K. 
McAllister et al. USFS, in litt. 2000). Thus we limited the delineation 
of proposed critical habitat to lands above this elevation. 
Additionally, in the North Cascades, features essential to the 
conservation of the lynx and the majority of the lynx records and 
evidence of reproduction are from east of the crest of the Cascade 
Mountains. Therefore, in the Cascades we used the international border 
with Canada, the Cascade crest and the 4,000-ft (1,219 m) elevation 
contour east of the crest as the boundary. In the Northern Rockies, the 
4,000-ft (1,219 m) contour was used as the primary boundary west of the 
Continental Divide. However, the climatic effects of the Continental 
Divide cause the 4,000-ft (1,219 m) elevation contour to be too broad 
east of the Continental Divide, such that it includes substantial areas 
of grassland habitats that do not contain features essential to the 
conservation of the lynx or important for snowshoe hares. Therefore, 
east of the Continental Divide in the Northern Rockies, we used USFS 
and National Park Service (NPS) boundaries to circumscribe critical 
habitat boundaries to more closely encompass essential features, recent 
records of lynx, including records of reproduction, and boreal forest 
currently occupied by lynx. The northern boundary for the Northern 
Rockies unit is the International border with Canada.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat, we are required to base critical habitat determinations on the 
best scientific data available and to consider those physical and 
biological features (primary constituent element) that are essential to 
the conservation of the species, and that may require special 
management considerations or protection. The regulations indicate these 
may include, but are not limited to: Space for individual and 
population growth and for normal behavior; food, water, air, light, 
minerals, or other nutritional or physiological requirements; cover or 
shelter; sites for breeding, reproduction, and rearing (or development) 
of offspring; and habitats that are protected from disturbance or are 
representative of the historic geographical and ecological 
distributions of a species.
    The area proposed for designation as critical habitat provides 
boreal forest habitat for breeding, non-breeding, and dispersing lynx 
in metapopulations across the species' range in the contiguous United 
States. No areas are being proposed solely because they provide habitat 
for dispersing animals. At this time, the biological or physical 
features of habitats lynx choose for dispersal is not well-understood; 
while it is assumed lynx would prefer to travel where there is forested 
cover, the literature contains many examples of lynx crossing large, 
unforested openings (e.g., Roe et al. 2000). The areas being proposed 
as critical habitat serve a variety of functions that include acting as 
a source of dispersing animals and providing habitat that may serve as 
travel corridors to facilitate dispersal and exploratory movements. The 
features or habitat components essential for the conservation of the 
species were determined from studies of lynx and snowshoe hare ecology.
    The specific biological and physical features, otherwise known as 
the primary constituent elements, essential to the conservation of the 
lynx are:
    (1) Boreal forest landscapes supporting a mosaic of differing 
successional forest stages and containing:
    (a) Presence of snowshoe hares and their preferred habitat 
conditions, which include dense understories of young trees or shrubs 
tall enough to protrude above the snow; and
    (b) Winter snow conditions that are generally deep and fluffy for 
extended periods of time; and

[[Page 68300]]

    (c) Sites for denning that have abundant coarse woody debris, such 
as downed trees and root wads.
    A description of the primary constituent elements are described 
below.

Boreal Forest Landscapes (Space for Individual and Population Growth 
and Normal Behavior)

    Lynx populations respond to biotic and abiotic factors at different 
scales. At the regional scale, snow conditions, boreal forest, and 
competitors (especially bobcat) influence the species' range (Aubry et 
al. 2000; McKelvey et al. 2000b; Hoving et al. 2005). At the landscape 
scale within each region, natural and human-caused disturbance 
processes (e.g., fire, wind, insect infestations and forest management) 
influence the spatial and temporal distribution of lynx populations by 
affecting the distribution of good habitat for snowshoe hares (Agee 
2000; Ruediger et al. 2000). At the stand-level scale, quality, 
quantity, and juxtaposition of habitats influence home range size, 
productivity, and survival (Aubry et al. 2000; Vashon et al. 2005a). At 
the substand scale, spatial distribution and abundance of prey and 
microclimate influence movements, hunting behavior, den, and resting 
site locations.
    All of the primary constituent elements of critical habitat for 
lynx are found in what is broadly described as the boreal forest 
landscape. In the contiguous United States, the boreal forest is more 
transitional rather than true boreal forest of northern Canada and 
Alaska (Agee 2000). This difference is because the boreal forest is at 
its southern limits in the contiguous United States, where it 
transitions to deciduous temperate forest in the northeast and Great 
Lakes and subalpine forest in the west (Agee 2000). We use the term 
``boreal forest'' because it generally encompasses most of the 
vegetative descriptions of the transitional forest types that comprise 
lynx habitat in the contiguous United States (Agee 2000).
    At a regional scale, lynx habitat is within the areas that 
generally support deep snow throughout the winter and that support 
boreal forest vegetation types (see below for more detail). In eastern 
North America, lynx distribution was strongly associated with areas of 
deep snowfall (greater than 268 cm (105 in) of mean annual snowfall) 
and 100 km2 (40 mi2) landscapes with a high 
proportion of regenerating forest (Hoving 2001). Hoving et al. (2004) 
concluded that the broad geographic distribution of lynx in eastern 
North America is most influenced by snowfall, but within areas of 
similarly deep snowfall, measures of forest succession become more 
important factors in determining lynx distribution.
    As described above (see ``Background''), boreal forests used by 
lynx are cool, moist and dominated by conifer tree species, primarily 
spruce and fir (Elliot-Fisk 1988; Agee 2000; Aubry et al. 2000; 
Ruediger et al. 2000). Boreal forest landscapes used by lynx are a 
heterogeneous mosaic of vegetative cover types and successional forest 
stages created by natural and human-caused disturbances (McKelvey et 
al. 2000a). Periodic vegetation disturbances stimulate development of 
dense understory or early successional habitat for snowshoe hares 
(Ruediger et al. 2000). In Maine, lynx were positively associated with 
landscapes altered by clearcutting 15 to 25 years previously (Hoving et 
al. 2004).
    The overall quality of the boreal forest landscape matrix and 
juxtaposition of stands in suitable condition within the landscape is 
important for both lynx and snowshoe hares in that it can influence 
connectivity or movements between suitable stands, availability of food 
and cover and spatial structuring of populations or subpopulations 
(Hodges 2000b; McKelvey et al. 2000a; Ricketts 2001; Walker 2005). For 
example, lynx foraging habitat must be near denning habitat to allow 
females to adequately provision dependent kittens, especially when the 
kittens are relatively immobile. In north-central Washington, hare 
densities were higher in landscapes with an abundance of dense boreal 
forest interspersed with small patches of open habitat, in contrast to 
landscapes composed primarily of open forest interspersed with few 
dense vegetation patches (Walker 2005). Similarly, in northwest 
Montana, connectivity of dense patches within the forest matrix 
benefited snowshoe hares (Ausband and Baty 2005). In mountainous areas, 
lynx appear to prefer flatter slopes (Apps 2000; McKelvey et al. 2000d; 
von Kienast 2003; Maletzke 2004).
    Individual lynx require large portions of boreal forest landscapes 
to support their home ranges and to facilitate dispersal and 
exploratory travel. The size of lynx home ranges is believed to be 
strongly influenced by the quality of the habitat, particularly the 
abundance of snowshoe hares, in addition to other factors such as 
gender, age, season, and density of the lynx population (Aubry et al. 
2000; Mowat et al. 2000). Generally, females with kittens have the 
smallest home ranges while males have the largest home ranges (Moen et 
al. 2004). Reported home range size varies from 31 km2 (12 
mi2) for females and 68 km2 (26 mi2) 
for males in Maine (Vashon et al. 2005a) to much larger ranges of 88 
km2 (34 mi2) for females and 216 km2 
(83 mi2) for males in northwest Montana (Squires et al. 
2004b).

Forest Type Associations

Maine

    Lynx were more likely to occur in 100 km2 (40 
mi2) landscapes with regenerating forest, and less likely to 
occur in landscapes with recent clearcut or partial harvest, (Hoving et 
al. 2004). Lynx in Maine select softwood (spruce and fir) dominated 
regenerating stands (Vashon et al. 2005a). Regenerating stands used by 
lynx generally develop 15-30 years after forest disturbance and are 
characterized by dense horizontal structure and high stem density 
within a meter of the ground. These habitats support high snowshoe hare 
densities (Homyack 2003; Fuller and Harrison 2005; Vashon et al. 
2005a). At the stand scale, lynx in northwestern Maine selected older 
(11 to 26 year-old), tall (4.6 to 7.3 m (15 to 24 ft)) regenerating 
clearcut stands and older (11 to 21 year-old) partially harvested 
stands (A. Fuller, University of Maine, unpubl. data).

Minnesota

    In Minnesota, lynx primarily occur in the Northern Superior Uplands 
Ecological Section of the Laurentian Mixed Forest Province. 
Historically, this area was dominated by red pine (Pinus resinosa) and 
white pine (P. strobus) mixed with aspen (Populus spp.), paper birch 
(Betula papyrifera), spruce, balsam fir (A. balsamifera) and jack pine 
(P. banksiana) (Minnesota Department of Natural Resources [Minnesota 
DNR] 2003).
    Preliminary research suggests lynx in Minnesota generally use 
younger stands (less than 50 years) with a conifer component in greater 
proportion than their availability (R. Moen, University of Minnesota, 
unpubl. data). Lynx prefer predominantly upland forests dominated by 
red pine, white pine, jack pine, black spruce (P. mariana), paper 
birch, quaking aspen (P. tremuloides), or balsam fir (R. Moen, unpubl. 
data).

Washington

    In the North Cascades in Washington, the majority of lynx 
occurrences were found above 1,250 m (4,101 ft) elevation (McKelvey et 
al. 2000b,d; von Kienast 2003; Maletzke 2004). In this area, lynx 
selected Engelman spruce (P. engelmanii)-subalpine-fir (A. lasiocarpa) 
forest cover types in winter

[[Page 68301]]

(von Kienast 2003, Maletzke 2004). Lodgepole pine (P. contorta) is a 
dominant tree species in the earlier successional stages of these 
climax cover types. Seral lodgepole stands contained dense understories 
and therefore received high use by snowshoe hares and lynx (Koehler 
1990; McKelvey et al. 2000d).

Northern Rockies

    In the Northern Rocky Mountains, the majority of lynx occurrences 
are associated with the Rocky Mountain Conifer Forest vegetative class 
(Kuchler 1964; McKelvey et al. 2000b) and occur above 1,250 m (4,101 
ft) elevation (Aubry et al. 2000; McKelvey et al. 2000b). The dominant 
vegetation that constitutes lynx habitat in these areas is subalpine 
fir, Engelman spruce and lodgepole pine (Aubry et al. 2000; Ruediger et 
al. 2000). As in the Cascades, lodgepole pine is an earlier 
successional stage of subalpine fir and Engelman spruce climax forest 
cover types.
a. Snowshoe Hares (Food)
    Snowshoe hare density is the most important factor explaining the 
persistence of lynx populations (Steury and Murray 2004). A minimum 
snowshoe hare density necessary to maintain a persistent, reproducing 
lynx population within the contiguous United States has not been 
determined, although Ruggiero et al. (2000) suggested that at least 0.5 
hares per hectare (ha) (0.2 hares per acre (ac)) may be necessary. 
Steury and Murray (2004) modeled lynx and snowshoe hare populations and 
predicted that a minimum of 1.1 to 1.8 hares per ha (0.4 to 0.7 hares 
per ac) was required for persistence of a reintroduced lynx population 
in the southern portion of the lynx range.
    The boreal forest landscape must contain a mosaic of forest stand 
successional stages to sustain lynx populations over the long term as 
the condition of individual stands changes over time. If the vegetation 
potential (or climax forest type) of a particular forest stand is 
conducive to supporting abundant snowshoe hares, it likely will also go 
through successional phases that are unsuitable as lynx foraging 
(snowshoe hare habitat) or lynx denning habitat (Agee 2000; Buskirk et 
al. 2000b). For example, a boreal forest stand where there has been 
recent disturbance, such as fire or timber harvest, resulting in little 
or no understory structure is unsuitable as snowhoe hare habitat for 
lynx foraging. That temporarily unsuitable stand may regenerate into 
suitable snowshoe hare (lynx foraging) habitat within 10 to 25 years, 
depending on local conditions (Ruediger et al. 2000). Forest management 
techniques that thin the understory, however, may render the habitat 
unsuitable for hares and, thus, for lynx (Ruediger et al. 2000; Hoving 
et al. 2004). Stands may continue to provide suitable snowshoe hare 
habitat for many years until woody stems in the understory become too 
sparse, as a result of undisturbed forest succession or management 
(e.g., clearcutting or thinning). Thus, if the vegetation potential of 
the stand is appropriate, a stand that is not currently in a condition 
that is suitable to support abundant snowshoe hares for lynx foraging 
or coarse woody debris for den sites has the capability to develop into 
suitable habitat for lynx and snowshoe hares with time.
    As described previously, snowshoe hares prefer boreal forest stands 
that have a dense horizontal understory to provide food, cover and 
security from predators. Snowshoe hares feed on conifers, deciduous 
trees and shrubs (Hodges 2000b). Snowshoe hare density is correlated to 
understory cover between approximately 1 to 3 m (3 to 10 ft) above the 
ground or snow level (Hodges 2000b). Habitats most heavily used by 
snowshoe hares are stands with shrubs, stands that are densely stocked, 
and stands at ages where branches have more lateral cover (Hodges 
2000b). In Maine, unthinned stands supporting 1.83 hares per ha (0.7 
hares per ac) had average stem densities of 11,600 stems per ha (4700 
stems per ac) (Homyack et al. 2004). In northcentral Washington, 
snowshoe hare density was highest in 20 year old lodgepole pine stands 
where the average density of trees and shrubs was 15,840 stems per ha 
(6415 stems per ac) (Koehler 1990). Generally, earlier successional 
forest stages support a greater density of horizontal understory and 
more abundant snowshoe hares (Buehler and Keith 1982; Wolfe et al. 
1982; Koehler 1990; Hodges 2000b; Homyack 2003; Griffin 2004); however, 
sometimes mature stands also can have adequate dense understory to 
support abundant snowshoe hares (Griffin 2004).
    In Maine, the highest snowshoe hare densities were found in 
regenerating softwood (spruce and fir) and mixedwood stands (Homyack 
2003, Fuller and Harrison 2005). In the north Cascades, the highest 
snowshoe hare densities were found in 20-year-old seral lodgepole pine 
stands with a dense understory (Koehler 1990). In montane and subalpine 
forests in northwest Montana, the highest snowshoe hare densities in 
summer were generally in younger stands with dense forest structure, 
whereas in winter, snowshoe hare densities were as high or higher in 
mature stands with dense understory forest structure (Griffin 2004). 
Snowshoe hare studies are just underway in Minnesota (University of 
Minnesota Web site https://www.nrri.umn.edu/lynx/research.html); 
therefore, results are not available at this time.
    Habitats supporting abundant snowshoe hares must be present in a 
large proportion of the landscape to support a viable lynx population. 
Broad-scale snowshoe hare density estimates are not available for the 
areas being proposed as lynx critical habitat; available snowshoe hare 
density estimates are only applicable for the immediate area and time 
frame for which the study was conducted and cannot be extrapolated 
further.
b. Snow Conditions (Other Physiological Requirements)
    As described in the ``Background'' above, snow conditions also 
determine the distribution of lynx. Deep, fluffy snow conditions likely 
restrict potential competitors such as bobcat or coyote from 
effectively encroaching on or hunting in winter lynx habitat. Snowfall 
was the strongest predictor of lynx occurrence at a regional scale 
(Hoving et al. 2005). In addition to snow depth, other snow properties, 
including surface hardness or sinking depth, are important factors in 
the spatial, ecological, and genetic structuring of the species 
(Stenseth et al. 2004).
    In the northeastern United States, lynx are most likely to occur in 
areas with a 10-year mean annual snowfall greater than 268 cm (105 in) 
(Hoving 2001). The Northern Superior Uplands section of Minnesota, 
which roughly corresponds to the area proposed as critical habitat, 
receives more of its precipitation as snow than any section in the 
State, has the longest period of snow cover, and the shortest growing 
season (Minnesota DNR 2003). Mean annual snowfall from 1971 to 2000 in 
this area was generally greater than 149 cm (55 in) (University of 
Minnesota 2005).
    Information on average snowfall or snow depths in mountainous areas 
such as the Cascades or northwest Montana is limited because there are 
few weather stations in these regions that have measured snow fall or 
snow depth over time. An important consideration is that the topography 
strongly influences local snow conditions. In the Cascades, at the 
Mazama station, average annual snowfall from 1948 to 1976 was 292 cm 
(115 in) (Western Regional Climate Center 2005). In Montana, at the 
Seeley

[[Page 68302]]

Lake Ranger Station, average annual snowfall from 1948 to 2005 was 315 
cm (124 in), while at the Troy station the average total snowfall from 
1961 to 1994 was 229 cm (90 in) (Western Regional Climate Center 2005).
c. Denning Habitat (Sites for Reproduction and Rearing of Offspring)
    Lynx den sites are found in mature and younger boreal forest stands 
that have a large amount of cover and downed, large woody debris. The 
structural components of lynx den sites are common features in managed 
(logged) and unmanaged (e.g., insect damaged, wind-throw) stands. 
Downed trees provide excellent cover for den sites and kittens and 
often are associated with dense woody stem growth.
    Sub-stand characteristics were evaluated for 26 lynx dens from 1999 
to 2004 in northwest Maine. Dens were found in several stand types. 
Modeling of den site variables determined that tip-up mounds (exposed 
roots from fallen trees) alone best explained den site selection (J. 
Organ, Service, unpubl. data). Tip-up mounds may purely be an index of 
downed trees, which were abundant on the landscape. Horizontal cover at 
5 m (16 ft) alone was the next best performing model (J. Organ, unpubl. 
data). Dead downed trees were sampled, but did not explain den site 
selection as well as tip-up mounds and cover at 5 m (16 ft). Lynx 
essentially select dense cover in a cover-rich area.
    In the North Cascades, Washington, lynx denned in mature (older 
than 250 years) stands with an overstory of Engelman spruce, subalpine 
fir and lodgepole pine with an abundance of downed woody debris 
(Koehler 1990). In this study, all den sites were located on north-
northeast aspects (Koehler 1990). In northwest Montana, the immediate 
areas around dens were in a variety of stand ages but all contained 
abundant woody debris including downed logs, blowdowns, and rootwads, 
and dense understory cover (Squires et al. 2004b). ). Information on 
den site characteristics in Minnesota has not yet been reported (Moen 
et al. 2004).

Primary Constituent Elements Summary

    The discussion above outlines those physical and biological 
features essential to the conservation of the lynx and provides a basis 
for their selection as the primary constituent element for this 
proposed critical habitat. The primary constituent elements comprise 
the essential features of boreal forest that (1) Provide adequate prey 
resources necessary for the persistence of local populations and 
metapopulations of lynx through reproduction; (2) act as a possible 
source of lynx for more peripheral boreal forested areas; (3) enable 
the maintenance of home ranges; (4) incorporate snow conditions for 
which lynx are highly specialized that give lynx a competitive 
advantage over potential competitors; (5) provide denning habitat; and 
(6) provide habitat connectivity for travel within home ranges, 
exploratory movements, and dispersal.

Criteria Used To Identify Critical Habitat

    To identify areas containing features that are essential to the 
conservation of the lynx, we considered the concepts introduced in the 
recovery outline for the species (Service 2005) and the above analysis 
concerning occupancy, evidence of reproduction, connectivity with 
adjacent lynx populations in Canada and the primary constituent 
elements. In summary, the area occupied by the lynx in the contiguous 
United States is broadly delineated by the distribution of the southern 
extensions of boreal forest, which occur in the Northeast (portions of 
Maine, New Hampshire, Vermont, New York); the western Great Lakes 
(portions of Minnesota, Wisconsin, Michigan); the Northern Rocky 
Mountains/Cascades (portions of Washington, Oregon, Idaho, Montana, 
northwestern Wyoming, Utah); and the Southern Rocky Mountains (portions 
of Colorado, southeastern Wyoming) (Agee 2000; McKelvey et al. 2000b; 
Hoving et al. 2003). Within this broad distribution the recovery 
outline (Service 2005) delineated core areas that contain consistent, 
verified records of lynx over time and evidence of reproduction within 
the past 20 years. The long-term occupation of these general areas by 
lynx supports the assumption that they contain habitats sufficient in 
quality and quantity to continue to sustain lynx populations. An 
additional factor strongly influencing most of these core areas is 
their connection with larger lynx populations in Canada. Each proposed 
critical habitat unit occurs within one of these core areas.
    The proposed critical habitat designation does not