# Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Contiguous United States Distinct Population Segment of the Canada Lynx (Lynx canadensis)

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URL: https://www.frixlaw.com/law-library/documents/fr%3A08-779

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** February 28, 2008
- **Citation:** 73 FR 10860

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R6-ES-2008-0026]
92210-1117-0000-B4]
RIN 1018-AV78
Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Contiguous United States Distinct Population Segment of the Canada Lynx (Lynx canadensis)

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), propose to revise designated critical habitat for the contiguous United States distinct population segment of the Canada lynx (
Lynx canadensis
) (lynx) under the Endangered Species Act of 1973, as amended (Act). In the contiguous United States, the lynx generally inhabits cold, moist boreal forests. Approximately 42,753 square miles (mi
2
) (110,727 square kilometers (km
2
)) fall within the boundaries of the proposed revised critical habitat designation. The proposed revised designation would add an additional 40,913 mi
2
(105,959 km
2
) to the existing critical habitat designation of 1,841 mi
2
(4,768 km
2
). The proposed revised critical habitat is located in Boundary County, Idaho; Aroostook, Franklin, Penobscot, Piscataquis, and Somerset Counties in Maine; Cook, Koochiching, Lake, and St. Louis Counties in Minnesota; Flathead, Glacier, Granite, Lake, Lewis and Clark, Lincoln, Missoula, Pondera, Powell, Teton, Gallatin, Park, Sweetgrass, Stillwater, and Carbon Counties in Montana; Chelan and Okanogan Counties in Washington; and Park, Teton, Fremont, Sublette, and Lincoln Counties in Wyoming.

DATES:

We will accept comments received or postmarked on or before April 28, 2008. We must receive requests for public hearings, in writing, at the address shown in the
ADDRESSES
section by April 14, 2008.

ADDRESSES:

You may submit comments by one of the following methods:

• Federal eRulemaking Portal:
http://www.regulations.gov.
Follow the instructions for submitting comments.

• U.S. mail or hand-delivery: Public Comments Processing, Attn: [FWS-R6-ES-2008-0026]; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203.

We will not accept e-mail or faxed comments. We will post all comments on
http://www.regulations.gov.
This generally means that we will post any personal information you provide us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT:

Mark Wilson, Field Supervisor, Montana Ecological Services Office, 585 Shepard Way, Helena, MT, 59601; telephone 406-449-5225. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

We intend that any final action resulting from this proposal will be as accurate and as effective as possible. Therefore, we request comments or suggestions on this proposed rule. We particularly seek comments concerning:

(1) The reasons why we should or should not designate specific habitat as “critical habitat” under section 4 of the Act (16 U.S.C. 1531
et seq.
).

(2) Specific information on:

• The amount and distribution of lynx habitat,

• What areas occupied at the time of listing and that contain features essential for the conservation of the species we should include in the designation and why that might be so, and

• What areas not occupied at the time of listing are essential to the conservation of the species and why that might be so.

(3) Comments or information that may assist us with identifying or clarifying the primary constituent element.

(4) Land use designations and current or planned activities in the areas proposed as critical habitat and their possible impacts on proposed revised critical habitat.

(5) Whether Tribal lands in the Northern Rockies, Maine, and Minnesota units need to be included as critical habitat pursuant to Secretarial Order Number 3206.

(6) Whether lands the Southern Rocky Mountains contain the physical and biological features that are essential for the conservation of the species and the basis for why that might be so

(7) Whether lands in any unoccupied areas, such as the “Kettle Range” in Ferry County, Washington, are essential to the conservation of lynx and the basis for why that might be so.

(8) How the proposed boundaries of the revised critical habitat could be refined to more closely circumscribe the boreal forest landscapes occupied by lynx. Refined maps that accurately depict the specific vegetation types on all land ownerships are not readily available. We are especially interested in this information for the Greater Yellowstone Area unit.

(9) Whether our proposed revised critical habitat for the lynx should be altered in any way to account for climate change.

(10) Whether the proposed revised critical habitat designation for the lynx should include private lands, or whether the proposed Federal lands are sufficient to conserve lynx.

(11) Whether U.S. Forest Service (USFS) lands that occur in the wildland-urban-interface (WUI) should be excluded from critical habitat under section 4(b)(2) of the Act so that fuels-reduction projects designed to protect human life and property from wildfire would not be impeded in any way in these areas.

(12) Whether the Greater Yellowstone Area is essential to the conservation of lynx. Lynx in this proposed unit occur at lower densities than in other proposed units, and the population is not connected to Canada, which is an important source of lynx in the United States.

(13) Any foreseeable economic, national security, or other potential impacts resulting from the proposed designation and, in particular, any impacts on small entities, and the benefits of including or excluding areas that exhibit these impacts.

(14) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

The size of the individual Indian reservation lands in the Northern Rockies, 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 proposal without including Tribal lands (see “Relationship of Critical Habitat to Tribal Lands” below).

The southern Rocky Mountains in Colorado, Utah, and southern Wyoming are disjunct from other lynx habitats in the United States and Canada. The nearest lynx population occurs in the Greater Yellowstone Area (GYA), which is a small, low density population also disjunct from other lynx populations and is unlikely to regularly supply dispersing lynx to the Southern Rockies. Native lynx were functionally extirpated

from their historic range in Colorado and southern Wyoming by the time the lynx was listed as a threatened species under the Act in 2000. In 1999, the State of Colorado began an intensive effort to reintroduce lynx. Although it is too early to determine whether the introduction will result in a self-sustaining population, the reintroduced lynx have produced kittens and now are distributed throughout the lynx habitat in Colorado and southern Wyoming. These animals are not designated as an experimental population under section 10(j) of the Act. Although Colorado's reintroduction effort is an important step toward the recovery of lynx, we are not proposing revised critical habitat in the Southern Rockies because of the current uncertainty that a self-sustaining lynx population will become established.

The Kettle Range in Washington historically supported lynx populations (Stinson 2001). However, although boreal forest habitat within the Kettle Range appears of high quality for lynx, there is no evidence that the Kettle Range is currently occupied by a lynx population nor has there been evidence of reproducing lynx in the Kettle Range in the past two decades (Koehler 2008).

Fuels-reduction projects in the WUI may degrade lynx habitat by reducing its ability to support snowshoe hares. For this reason, if WUI areas were designated as revised critical habitat, fuels-reduction projects may be impaired or delayed as a result of requirements under section 7(a)(2) of the Act, which could lead to reduced effectiveness of the fuels-reduction, and increased risk to human life and property. Mapped WUI areas can be viewed on the Internet at:
ftp://ftp2.fs.fed.us/incoming/r1/FWS/wui_1mile_buffer_oct06.pdf.

In addition to public comments received on this proposed rule, between the proposed and final rules, the Service will analyze the following for its relevance in revising critical habitat for lynx: (1) Comments received in response to our initiation of a 5-year review for lynx; (2) a new study addressing effects of snowmobile trails on coyote movements within lynx home ranges (Kolbe
et al.
2007, pp. 1409-1418); (3) a study on lynx prey selection (Squires and Ruggiero 2007, pp. 310-315); (4) new reports we have received on the numbers and distribution of lynx in some locations; (5) a newly released study on the effects of climate change on snowpack in western mountains and how that may affect lynx, snowshoe hares, and their habitats (Gonzalez
et al.
2007); and (6) additional new studies (
e.g.
, Knowles
et al.
2006 and Danby and Hick 2007) that may provide insight on changes to lynx habitat. If necessary and appropriate, revisions to this proposed rule will be made to address this information. We will also be revising the economic analysis and environmental assessment prepared for the previous designation and providing drafts of the new economic analysis and environmental assessment to the public before finalizing this proposal.

On the basis of public comment, during the development of the revised final rule we may find, among other things, that areas proposed are not essential to the conservation of the species, are appropriate for exclusion under section 4(b)(2) of the Act, or are not appropriate for exclusion. In all of these cases, this information will be incorporated into the revised final designation. Further, we may find as a result of public comments that areas not proposed should also be designated as critical habitat. Final management plans 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.

You may submit your comments and materials concerning this proposed rule by one of the methods listed in the
ADDRESSES
section. We will not accept comments sent by e-mail or fax or to an address not listed in the
ADDRESSES
section. We will not accept anonymous comments; your comment must include your first and last name, city, State, country, and postal (zip) code. Finally, we will not consider hand-delivered comments that we do not receive, or mailed comments that are not postmarked, by the date specified in the
DATES
section.

We will post your entire comment—including your personal identifying information—on
http://www.regulations.gov
. If you provide personal identifying information in addition to the required items specified in the previous paragraph, such as your street address, phone number, or e-mail address, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so.

Comments and materials we receive, as well as supporting documentation we used in preparing this revised proposed rule, will be available for public inspection on
http://www.regulations.gov
, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Montana Ecological Services Office (
see

FOR FURTHER INFORMATION CONTACT
). Maps of the proposed revised critical habitat are also available on the Internet at
http://mountain-prairie.fws.gov/species/mammals/lynx/
.

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 30 to 35 inches (in) (75 to 90 centimeters (cm)) long and weighing 18 to 23 pounds (8 to 10.5 kilograms) (Quinn and Parker 1987, Table 1). 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, p. 744; Quinn and Parker 1987, pp. 684-685; Aubry
et al.
2000, pp. 375-378). Lynx and snowshoe hares are strongly associated with what is broadly described as boreal forest (Bittner and Rongstad 1982, p. 154; McCord and Cardoza 1982, p. 743; Quinn and Parker 1987, p. 684; Agee 2000, p. 39; Aubry
et al.
2000, pp. 378-382; Hodges 2000a, pp. 136-140 and 2000b, pp. 183-191; McKelvey
et al.
2000b, pp. 211-232). The predominant vegetation of boreal forest is conifer trees, primarily species of spruce (
Picea
spp.) and fir (
Abies
spp.) (Elliot-Fisk 1988, pp. 34-35, 37-42). 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, pp. 40-41). 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, p. 684-685; Agee 2000, pp. 39-47; Aubry
et al.
2000, pp. 373-375; Buskirk
et al.
2000b, pp. 397-405; Ruggiero
et al.
2000, pp. 445-447). In mountainous areas, the boreal forests that lynx use are characterized by scattered moist forest types with high hare densities in a matrix of other habitats (
e.g.
, hardwoods, dry forest, non-forest) with low hare densities. In these areas, lynx incorporate the matrix habitat (non-boreal forest habitat elements) into their home ranges and use it for traveling between patches of boreal forest that support high hare densities where most foraging occurs.

Snow conditions also determine the distribution of lynx (Ruggiero
et al.
2000, pp. 445-449). 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, p. 748; Buskirk
et al.
2000a, pp. 86-95; Ruediger
et al.
2000, p. 1-11; Ruggiero
et al.
2000, pp. 445, 450). 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, p. 748) or coyotes.

Lynx Habitat Requirements

Because of the patchiness and temporal nature of high quality snowshoe hare habitat, lynx populations require large boreal forest landscapes to ensure that sufficient high quality snowshoe hare habitat is available 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, p. 25). Individual lynx maintain large home ranges (reported as generally ranging between 12 to 83 mi
2
(31 to 216 km
2
)) (Koehler 1990, p. 847; Aubry
et al.
2000, pp. 382-386; Squires and Laurion 2000, pp. 342-347; Squires
et al.
2004b, pp. 13-16, Table 6; Vashon
et al.
2005a, pp. 7-11). The size of lynx home ranges varies depending on abundance of prey, the animal's gender and age, the season, and the density of lynx populations (Koehler 1990, p. 849; Poole 1994, pp. 612-616; Slough and Mowat 1996, pp. 951, 956; Aubry
et al.
2000, pp. 382-386; Mowat
et al.
2000, pp. 276-280; Vashon
et al.
2005a, pp. 9-10). 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, pp. 123-128; Buehler and Keith 1982, pp. 24, 28; Koehler 1990, p. 849; Koehler and Aubry 1994, p. 84). Additionally, the presence of more snowshoe hare predators and competitors at southern latitudes may inhibit the potential for high-density hare populations (Wolff 1980, p. 128). As a result, lynx generally occur at relatively low densities in the contiguous United States compared to the high lynx densities that occur in the northern boreal forest of Canada (Aubry
et al.
2000, pp. 375, 393-394) or the densities of species such as the bobcat, which is a habitat and prey generalist.

Lynx are highly mobile and generally move long distances (greater than 60 mi (100 km)) (Aubry
et al.
2000, pp. 386-387; Mowat
et al.
2000, pp. 290-294). Lynx disperse primarily when snowshoe hare populations decline (Ward and Krebs 1985, pp. 2821-2823; O'Donoghue
et al.
1997, pp. 156, 159; Poole 1997, pp. 499-503). Subadult lynx disperse even when prey is abundant (Poole 1997, pp. 502-503), presumably to establish new home ranges. Lynx also make exploratory movements outside their home ranges (Aubry
et al.
2000, p. 386; Squires
et al.
2001, pp. 18-26).

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, pp. 47-48; Agee 2000, pp. 47-69). As a result, lynx habitat within the boreal forest landscape is typically patchy because the boreal forest contains stands of differing ages and conditions, some of which are suitable as lynx foraging or denning habitat (or will become suitable in the future due to forest succession) and some of which serve as travel routes for lynx moving between foraging and denning habitat (McKelvey
et al.
2000a, pp. 427-434; Hoving
et al.
2004, pp. 290-292).

Snowshoe hares comprise a majority of the lynx diet (Nellis
et al.
1972, pp. 323-325; Brand
et al.
1976, pp. 422-425; Koehler 1990, p. 848; Apps 2000, pp. 358-359, 363; Aubry
et al.
2000, pp. 375-378; Mowat
et al.
2000, pp. 267-268; von Kienast 2003, pp. 37-38; Squires
et al.
2004b, p. 15, Table 8). When snowshoe hare populations are low, female lynx produce few or no kittens that survive to independence (Nellis
et al.
1972, pp. 326-328; Brand
et al.
1976, pp. 420, 427; Brand and Keith 1979, pp. 837-838, 847; Poole 1994, pp. 612-616; Slough and Mowat 1996, pp. 953-958; O'Donoghue
et al.
1997, pp. 158-159; Aubry
et al.
2000, pp. 388-389; Mowat
et al.
2000, pp. 285-287). Lynx prey opportunistically on other small mammals and birds, particularly during lows in snowshoe hare populations, but alternate prey species may not sufficiently compensate for low availability of snowshoe hares, resulting in reduced lynx populations (Brand
et al.
1976, pp. 422-425; Brand and Keith 1979, pp. 833-834; Koehler 1990, pp. 848-849; Mowat
et al.
2000, pp. 267-268).

In northern Canada, lynx populations fluctuate in response to the cycling of snowshoe hare populations (Hodges 2000a, pp. 118-123; Mowat
et al.
2000, pp. 270-272). 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 their range in the contiguous United States (Hodges 2000b, pp. 165-173). 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 reproduction 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, p. 442; Ward and Krebs 1985, pp. 2821-2823; Murray
et al.
1994, p. 1450; O'Donoghue
et al.
1997, pp. 155, 159-160 and 1998, pp. 178-181). 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, pp. 665-669; Litvaitis
et al.
1985, pp. 869-872; Hodges 2000a, pp. 136-140 and 2000b, pp. 183-195). Generally, hare densities are higher in regenerating, earlier successional forest stages because they have greater understory structure than mature forests (Buehler and Keith 1982, p. 24; Wolfe
et al.
1982, pp. 665-669; Koehler 1990, pp. 847-848; Hodges 2000b, pp. 183-195; Homyack 2003, p. 63, 141; Griffin 2004, pp. 84-88). However, snowshoe hares can be abundant in mature forests with dense understories (Griffin 2004, pp. 53-54).

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, pp. 743-744; Koehler

1990, pp. 847-849; Slough 1999, p. 607; Squires and Laurion 2000, pp. 346-347; Organ 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, pp. 10-11).

Future of Lynx Habitat

In 2003, we determined that climate change was not a threat to lynx because the best available science we had at that time (Hoving 2001) was too uncertain in nature (68 FR 40083). Since that time, new information on regional climate changes and potential effects to lynx habitat has been developed (
e.g.,
Gonzalez
et al.
2007, entire; Knowles
et al.
2006, pp. 4545-4559; Danby and Hick 2007, pp. 358-359) that suggests that climate change may be an issue of concern for the future conservation of lynx. This information, combined with the information in Hoving 2001, still needs to be evaluated further to determine how climate change might affect lynx and lynx habitat. We are evaluating this information in the 5-year review we are conducting for lynx.

At this time, we find it appropriate to propose revised critical habitat in areas that are occupied and currently contain the physical and biological features essential to the conservation of the lynx. Revisions to the critical habitat designation may be necessary in the future to accommodate shifts in the occupied range of the lynx. To the extent lynx distribution and habitat is likely to shift upward in elevation within its currently occupied range as the temperatures increase (Gonzalez
et al.
2007, pp. 7, 13-14,19), the proposed revised critical habitat units include the highest-elevation habitats that lynx would be able to use in that event.

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), the clarification of findings published in the
Federal Register
on July 3, 2003 (68 FR 40076), and the final rule designating critical habitat for lynx published in the
Federal Register
on November 9, 2006 (71 FR 66007). On July 20, 2007, the Service announced that we would review the November 9, 2006 final rule after questions were raised about the integrity of scientific information used and whether the decision made was consistent with the appropriate legal standards. Based on our review of the previous final critical habitat designation, we have determined that it is necessary to revise critical habitat, and this rule proposes those revisions. On January 15, 2008, the U.S. District Court for the District of Columbia issued an order stating the Service's deadlines for a proposed rule for revised critical habitat by February 15, 2008, and a final rule for revised critical habitat by February 15, 2009.

Critical Habitat

Critical habitat is defined in section 3 of the Act as:

(1) 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

(a) Essential to the conservation of the species and

(b) That may require special management considerations or protection; and

(2) 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, as defined under section 3 of the Act, means the use of all methods and procedures that are necessary to bring any endangered species or threatened species to the point at which the measures provided under the Act are no longer necessary.

Critical habitat receives protection under section 7 of the Act through the prohibition against Federal agencies carrying out, funding, or authorizing activities that result in the destruction or adverse modification of critical habitat. Section 7 of the Act requires consultation on Federal actions that may affect 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 the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by the landowner. Where the landowner seeks or requests Federal agency funding or authorization of an activity that may affect a listed species or critical habitat, the consultation requirements of section 7 would apply. Nonetheless, even in the event a project with a Federal nexus may result in the destruction or adverse modification of critical habitat, the landowner's obligation is not to restore or recover the species, but to implement reasonable and prudent alternatives to avoid destruction or adverse modification of critical habitat.

For inclusion in a critical habitat designation, habitat within the geographical area occupied by the species at the time it was listed must contain physical and biological features that are essential to the conservation of the species. Consistent with this requirement, the Service identifies, to the extent known using the best scientific data available, habitat areas on which are found the physical and biological features essential, as defined at 50 CFR 424.12(b), and identifies the quantity and spatial arrangement of such areas to ensure that the areas designated as critical habitat are essential for the conservation of the species. Occupied habitat that contains the physical and biological features essential to the conservation of the species meets the definition of critical habitat only if those features may require special management considerations or protection.

Under the Act, we can designate unoccupied areas as critical habitat only when we determine that the best available scientific data demonstrate that the designation of that area is essential to the conservation of the species.

Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific and commercial data available. Further, our Policy on Information Standards Under the Endangered Species Act (published in the
Federal Register
on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), and our associated Information Quality Guidelines provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific data available. These documents require our biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat.

When we are determining which areas should be proposed as critical habitat, our primary source of information is generally the information developed during the listing process for the species. Additional information sources may 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.

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 we may eventually determine, based on scientific data not now available to the Service, are necessary for the recovery of the species. For these reasons, a critical habitat designation does not signal that habitat outside the designated area is unimportant or may not be required for recovery of the species.

Areas that support populations, but are outside the critical habitat designation, may continue to be subject to conservation actions we implement under section 7(a)(1) of the Act. They are also subject to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best available scientific information at the time of the agency 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 available information at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans (HCPs), section 7 consultation, or other species conservation planning efforts if new information calls for a different outcome.

Methods

As required by section 4(b)(2) of the Act, we use the best scientific data available to determine areas occupied at the time of listing that contain the features essential to the conservation of the lynx. We have reviewed the approach to the conservation of the lynx provided in its recovery outline (Service 2005, entire) and information from State, Federal, and Tribal agencies, and from academia and private organizations that have collected scientific data on lynx. The Service also obtained information about critical habitat for lynx in 2005 and 2006 during development of rules for lynx critical habitat. The Service also initiated a 5-year review for the lynx on April 18, 2007 (72 FR 19549). Information gathered for that purpose will be used in completing our final designation.

We have used information we reviewed for the prior designation of critical habitat, including data in reports submitted by researchers holding recovery permits under section 10(a)(1)(A) of the Act, research published in peer-reviewed articles and presented in academic theses, agency reports, unpublished data, and various Geographic Information System (GIS) data layers (
e.g.,
land cover type information, land ownership information, snow depth information, topographic information, locations of lynx obtained from radio- or Global Positioning System (GPS) collars, and locations of lynx confirmed via deoxyribonucleic acid (DNA) analysis or other verified records).

Primary Constituent Elements

In accordance with section 3(5)(A)(i) of the Act and the regulations at 50 CFR 424.12(b), in determining which areas occupied at the time of listing to propose as critical habitat, we consider the physical and biological features that are essential to the conservation of the species to be the primary constituent elements (PCEs) laid out in the appropriate quantity and spatial arrangement for conservation of the species. In general, PCEs include, but are not limited to:

(1) Space for individual and population growth and for normal behavior;

(2) Food, water, air, light, minerals, or other nutritional or physiological requirements;

(3) Cover or shelter;

(4) Sites for breeding, reproduction, or rearing (or development) of offspring; and

(5) Habitats that are protected from disturbance or are representative of the historic, geographical, and ecological distributions of a species.

When considering the designation of critical habitat, we must focus on the principal biological or physical constituent elements within the defined area that are essential to the conservation of the species. As previously stated, we consider the physical and biological features that are essential to the conservation of the species to be the primary constituent elements (PCEs) laid out in the appropriate quantity and spatial arrangement for conservation of the species. As such, we derive the PCEs required for lynx from its biological needs. The area proposed for designation as revised critical habitat provides boreal forest habitat for breeding, non-breeding, and dispersing lynx in metapopulations across their range in the contiguous United States. We are not proposing any areas solely because they provide habitat for dispersing animals because the areas we are proposing serve a variety of functions that include acting as a source of dispersing animals and providing habitat that serves as travel corridors to facilitate dispersal and exploratory movements. The primary constituent elements and therefore the resulting physical and biological features essential for the conservation of the species were determined from studies of lynx and snowshoe hare ecology.

Space for Individual and Population Growth and Normal Behavior—Boreal Forest Landscapes

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, pp. 378-380; McKelvey
et al.
2000b, pp. 242-253; Hoving
et al.
2005, p. 749). 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, pp. 47-73; Ruediger
et al.
2000, pp. 1-3, 2-2, 2-6, 7-3). At the stand-level scale, quality, quantity, and juxtaposition of habitats influence home range size, productivity, and survival (Aubry
et al.
2000, pp. 380-390; Vashon
et al.
2005a, pp. 9-11). At the substand scale, spatial distribution, abundance of prey, and microclimate influence movements, hunting behavior, and den and resting site locations.

All of the components of the physical and biological features of proposed revised critical habitat for lynx are found within large landscapes in what is broadly described as the boreal forest or cold temperate forest (Frelich and Reich 1995, p. 325; Agee 2000, pp. 43-46). The primary constituent element is broadly described as the boreal forest landscape. In the contiguous United States, the boreal forest is more transitional than the true boreal forest of northern Canada and Alaska (Agee 2000, pp. 43-46). 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, pp. 43-46). 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, pp. 40-41).

At a regional scale, lynx habitat exists in areas that generally support deep snow throughout the winter and boreal forest vegetation types (see below for more detail). In eastern North America,

lynx distribution is strongly associated with areas of deep snowfall (greater than 105 in (268 cm) of mean annual snowfall) and 40 mi
2
(100 km
2
) landscapes with a high proportion of regenerating forest (Hoving 2001, pp. 75, 143). 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 (Hoving
et al.
2004, p. 291).

Boreal forests used by lynx are cool, moist, and dominated by conifer tree species, primarily spruce and fir (Agee 2000, pp. 40-46; Aubry
et al.
2000, pp. 378-383; Ruediger
et al.
2000, pp. 4-3, 4-8, 4-11, 4-25, 4-26, 4-29, 4-30). 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, pp. 426, 434). Periodic vegetation disturbances stimulate development of dense understory or early successional habitat for snowshoe hares (Ruediger
et al.
2000, pp. 1-3, 1-4, 7-4, 7-5). In Maine, lynx were positively associated with landscapes clearcut 15 to 25 years previously (Hoving
et al.
2004, p. 291).

The overall quality of the boreal forest landscape matrix and the juxtaposition of stands in suitable condition within that landscape is important for both lynx and snowshoe hares in that it influences connectivity or movements between suitable stands, availability of food and cover, and spatial structuring of populations or subpopulations (Hodges 2000b, pp. 181-195; McKelvey
et al.
2000a, pp. 431-432; Walker 2005, p. 79). For example, lynx foraging habitat must be near denning habitat to allow females to adequately provide for 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, p. 79). Similarly, in northwest Montana, connectivity of dense patches within the forest matrix benefited snowshoe hares (Ausband and Baty 2005, p. 209). In mountainous areas, lynx appear to prefer flatter slopes (Apps 2000, p. 361; McKelvey
et al.
2000d, p. 333; von Kienast 2003, p. 21, Table 2; Maletzke 2004, pp. 17-18).

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, pp. 382-385; Mowat
et al.
2000, pp. 276-280). Generally, females with kittens have the smallest home ranges while males have the largest home ranges (Moen
et al.
2004, p. 11). Reported home range size varies from 12 mi
2
(31 km
2
) for females and 26 mi
2
(68 km
2
) for males in Maine (Vashon
et al.
2005a, p. 7), 8 mi
2
(21 km
2
) for females and 119 mi
2
(307 km
2
) for males in Minnesota (Moen
et al.
2005, p. 12), and 34 mi
2
(88 km
2
) for females and 83 mi
2
(216 km
2
) for males in northwest Montana (Squires
et al.
2004b, pp. 15-16).

The dynamic nature of boreal forest landscapes means that lynx home ranges will incorporate a variety of forest stands that are in different stages of succession and have differing potential to produce prey. In addition, due to the naturally marginal nature of lynx habitat within the DPS, the moist boreal forest types that snowshoe hares prefer often occur in patches dissected or surrounded by matrix habitat. Lynx use the matrix habitat primarily as travel routes between foraging areas and denning areas. Although they are not dependent on the specific vegetative condition of these habitats (
i.e.,
they are not sensitive to forest management practices), the importance of these areas as travel routes makes them necessary habitat components for lynx.

Forest Type Associations

Maine

Lynx are more likely to occur in 40 mi
2
(100 km
2
) landscapes with regenerating forest, and less likely to occur in landscapes with recent clearcut or partial harvest, (Hoving
et al.
2004, pp. 291-292). Lynx in Maine select softwood (spruce and fir) dominated, regenerating stands (Vashon
et al.
2005a, p. 8). 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, p. 63; Fuller and Harrison 2005, pp. 716, 719; Vashon
et al.
2005a, pp. 10-11). 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 (
Pinus strobus
) mixed with aspen (
Populus
spp.), paper birch (
Betula papyrifera
), spruce, balsam fir (
Abies balsamifera
), and jack pine (
Pinus banksiana
) (Minnesota Department of Natural Resources [Minnesota DNR] 2003, p. 2).

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 (
Picea mariana
), paper birch, quaking aspen (
Populus 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, p. 243 and 2000d, p. 321; von Kienast 2003, p. 28, Table 2; Maletzke 2004, p. 17). In this area, lynx selected Engelman spruce (
Picea engelmanii
)-subalpine fir (
Abies lasiocarpa
) forest cover types in winter (von Kienast 2003, p. 28; Maletzke 2004, pp. 16-17). Lodgepole pine (
Pinus 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, pp. 847-848; McKelvey
et al.
2000d, pp. 332-335).

Northern Rockies

In the Northern Rocky Mountains, the majority of lynx occurrences are associated with the Rocky Mountain Conifer Forest vegetative class (Kuchler 1964, p. 5; McKelvey
et al.
2000b, p. 246) and occur above 1,250 m (4,101 ft) elevation (Aubry
et al.
2000, pp. 378-380; McKelvey
et al.
2000b, pp. 243-245). The dominant vegetation that constitutes lynx habitat in these areas is subalpine fir, Engelman spruce, and lodgepole pine (Aubry
et al.
2000, p. 379; Ruediger
et al.
2000, pp. 4-8—4-10). As in the Cascades, lodgepole pine is an earlier successional stage of subalpine fir and Engelman spruce climax forest cover types.

Greater Yellowstone Area

Lynx habitat in the GYA is similar to the Northern Rockies in that lynx

occurrences are generally associated with the Rocky Mountain Conifer Forest vegetative class. The primary areas of lynx occurrence in this unit occur between 7,382 and 9,843 ft (2,250 and 3,000 m) elevation (Aubry
et al.
2000, p. 379; McKelvey
et al.
2000b, Figure 8.18). However, lynx are not limited to these elevation zones. The dominant vegetation that constitutes lynx habitat in these areas is subalpine fir, Engelman spruce, and lodgepole pine (Aubry
et al.
2000, pp. 378-382; Ruediger
et al.
2000, pp. 1-2, 1-3; Murphy
et al.
2004, pp. 9-11). Lodgepole pine is an earlier successional stage of subalpine fir and Engelman spruce cover types. The vegetation characteristics in the GYA that support snowshoe hare populations (and form the basis for lynx populations) are typically found in a widely scattered mosaic of matrix habitat types (Murphy
et al.
2005, p. 8-11; Hodges and Mills 2005, p. 6; Agee 2000, p. 48). In the GYA, lynx exploit hare populations in disjunct patches of mesic boreal forest that support relatively dense understories (Hodges and Mills 2005, pp. 4-6). In most cases, lynx home ranges in the GYA will by necessity incorporate habitat that is not typically considered lynx foraging habitat, and is used primarily for travel.

Food, Water, Air, Light, Minerals, Or Other Nutritional Or Physiological Requirements

a. Snowshoe Hares (Food)

Snowshoe hare density is the most important factor explaining the persistence of lynx populations (Steury and Murray 2004, p. 136). 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, pp. 446-447) suggested that at least 0.2 hares per acre (0.5 hares per hectare) may be necessary. Steury and Murray (2004, p. 137) modeled lynx and snowshoe hare populations and predicted that a minimum of 0.4 to 0.7 hares per acre (1.1 to 1.8 hares per hectare) 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 or denning habitat (Agee 2000, pp. 62-72; Buskirk
et al.
2000b, pp. 403-408). For example, a boreal forest stand where there has been recent disturbance, such as fire or timber harvest, that has resulted in little or no understory structure is unsuitable as snowhoe hare habitat for lynx foraging. That stand may regenerate into suitable snowshoe hare (lynx foraging) habitat within 10 to 25 years, depending on local conditions (Ruediger
et al.
2000, pp. 1-3, 1-4, 2-2—2-5). However, forest management techniques that thin the understory may render the habitat unsuitable for hares and, thus, for lynx (Ruediger
et al.
2000, pp. 2-4—3-2; Hoving
et al.
2004, pp. 291-292). 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, pp. 181-183). Snowshoe hare density is correlated to understory cover between approximately 3 to 10 ft (1 to 3 m) above the ground or snow level (Hodges 2000b, p. 184, Table 7.5). 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, p. 184). In Maine, the snowshoe hare densities were highest in the stands supporting high conifer stem densities (Homyack
et al.
2004, p. 195; Robinson 2006, p. 69). In northcentral Washington, snowshoe hare density was highest in 20-year-old lodgepole pine stands where the average density of trees and shrubs was 6,415 stems per acre (ac) (15,840 stems/hectare (ha)) (Koehler 1990, p. 848). Generally, earlier successional forest stages support a greater density of horizontal understory and more abundant snowshoe hares (Buehler and Keith 1982, p. 24; Wolfe
et al.
1982, pp. 668-669; Koehler 1990, pp. 847-848; Hodges 2000b, pp. 184-191; Griffin 2004, pp. 84-88); however, sometimes mature stands also can have adequate dense understory to support abundant snowshoe hares (Griffin 2004, p. 88). In Montana, lynx favor multi-story stands, often in older age classes, where tree boughs touch the snow surface but where stem density is low (Squires 2006, p. 4).

In Maine, the highest snowshoe hare densities were found in regenerating softwood (spruce and fir) and mixed wood stands (Fuller and Harrison 2005, pp. 716, 719; Robinson 2006, p. 69). 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, pp. 847-848). In montane and subalpine forests in northwest Montana, the highest snowshoe hare densities in summer were generally in younger stands with dense forest structure; in winter snowshoe hare densities were as high or higher in mature stands with dense understory forest structure (Griffin 2004, p. 53). Snowshoe hare studies are just underway in Minnesota (Moen
et al.
2005, p. 18); therefore, results on habitat relationships are still preliminary. In the GYA, the highest snowshoe hare densities were found in a douglas fir site and a few regenerating lodgepole pine and lodgepole stands that had a lodgepole understory. Low hare densities were found in most regenerating lodgepole stands, most likely due to low stem densities (Hodges and Mills 2005, p. 6). Spruce-fir forests were the stand type most likely to support snowshoe hares; however, hare densities were never high at these sites.

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 we are proposing as lynx revised 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” section 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, p. 746, Table 5). 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, p. 75).

In the northeastern United States, lynx are most likely to occur in areas with a 10-year mean annual snowfall greater than 105 in (268 cm) (Hoving 2001, p. 75). The Northern Superior Uplands section of Minnesota, which roughly corresponds to the area proposed as revised critical habitat in that State, receives more of its precipitation as snow than any section in the State, has the longest period of snow cover, and has the shortest growing season (Minnesota DNR 2003, p. 2). Mean annual snowfall from 1971 to 2000 in this area was generally greater than 55 in (149 cm) (University of Minnesota 2005).

Information on average snowfall or snow depths in mountainous areas such as the Cascades or northwest Montana is limited because few weather stations in these regions have measured snow fall or snow depth over time. Topography strongly influences local snow conditions. In the Cascades, at the Mazama station, average annual snowfall from 1948 to 1976 was 115 in (292 cm) (Western Regional Climate Center 2005). In Montana, at the Seeley Lake Ranger Station, average annual snowfall from 1948 to 2005 is 124 in (315 cm), while at the Troy station the average total snowfall from 1961 to 1994 was 90 in (229 cm) (Western Regional Climate Center 2005).

We considered the effect climate change could have on average snowfall or snow depths when we developed this proposed rule. We have information to indicate that up to two-thirds of the lynx range in the lower 48 States may become unsuitable by 2100 (Gonzalez
et al.
2007, pp. 4, 7-8, 10, 13-14, 19). However, we have used current climate information in developing this rule because, until regional climate projections are more certain, we find it is appropriate to designate critical habitat for lynx where they currently exist. Projections for habitat loss go out over the next 100 years. If designated habitat becomes unsuitable for lynx in the future due to climate change, the Service will revise critical habitat to remove unsuitable habitat and add new suitable habitat in order to seek to facilitate the shift in lynx range that climate change may cause. Lynx distribution and habitat is likely to shift upward in elevation and northward in latitude as temperatures increase (Gonzalez
et al.
2007, pp. 7, 13-14, 19). All proposed revised critical habitat units include the highest-elevation habitats that lynx would be able to use in the event that they move to higher elevations in response to climate change. Additionally, any northward shifts in range would likely move the species and its suitable habitat into Canada. Four of the five proposed revised critical habitat units use the United States/Canada border as their northern boundary.

Sites for Breeding, Reproduction, or Rearing (or Development) of Offspring—Denning Habitat

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.

Site characteristics were evaluated for 26 lynx dens from 1999 to 2004 in northwest Maine. Dens were found in several stand types. 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 16 ft (5 m) alone was the next best predictor of denning (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 16 ft (5 m). 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, p. 847). In this study, all den sites were located on north-northeast aspects (Koehler 1990, p. 847). In northwest Montana, areas around dens were a variety of ages but all contained abundant woody debris including downed logs, blowdowns, and rootwads, and dense understory cover (Squires
et al.
2004b, Table 3). Information on den site characteristics in Minnesota has not yet been reported (Moen
et al.
2005, p. 8).

Primary Constituent Element for Lynx

Within the geographical area we know to be occupied by the lynx, we must identify the primary constituent elements (PCEs) laid out in the quantity and spatial arrangement essential to the conservation of the species (
i.e.,
essential physical and biological features) that may require special management considerations or protections.

Based on the above needs and our current knowledge of the life history, biology, and ecology of the species, we have determined that the primary constituent element essential to the conservation of the lynx is:

(1) Boreal forest landscapes supporting a mosaic of differing successional forest stages and containing:

(a) Presence of snowshoe hares and their preferred habitat conditions, including dense understories of young trees or shrubs tall enough to protrude above the snow;

(b) Winter snow conditions that are generally deep and fluffy for extended periods of time;

(c) Sites for denning having abundant, coarse, woody debris, such as downed trees and root wads; and

(d) Matrix habitat (
e.g.,
hardwood forest, dry forest, non-forest, or other habitat types that do not support snowshoe hares) that occurs between patches of boreal forest in close juxtaposition (at the scale of a lynx home range) such that lynx are likely to travel through such habitat while accessing patches of boreal forest within a home range. The important aspect of matrix habitat for lynx is that these habitats retain the ability to allow unimpeded movement of lynx through them as lynx travel between patches of boreal forest.

We designed the proposed revised critical habitat units to capture these elements of the PCE laid out in the quantity and spatial arrangement essential to the conservation of the species (
i.e.,
essential physical and biological features). To do this, we mapped units across the geographic range of the species in the United States to protect populations in the event of catastrophic events that could impact a portion of the range. We designed each unit to be large enough to encompass the temporal and spatial changes in habitat and snowshoe hare populations to support interbreeding lynx populations or metapopulations over time.

Special Management Considerations or Protections

When designating critical habitat, we assess whether the occupied areas contain the physical and biological features that are essential to the conservation of the species and that may require special management considerations or protections.

The area proposed for designation as revised critical habitat will require some level of management to address the current and future threats to the lynx and to maintain the physical and

biological features essential to the conservation of the species. In all units, special management will be required to ensure that boreal forest landscapes provide a mosaic of forest stands of various ages to provide abundant prey habitat, denning habitat, and connectivity within the landscape. The designation of critical habitat does not imply that lands outside of critical habitat do not play an important role in the conservation of the lynx. Federal activities that may affect areas outside of critical habitat, such as forest management, development, and road construction, are still subject to review under section 7 of the Act if they may affect lynx because Federal agencies must consider both effects to lynx and effects to critical habitat independently. The prohibitions of section 9 of the Act (
e.g.,
harm, harass, capture, kill) also continue to apply both inside and outside of designated critical habitat.

Special management direction for lynx has been applied to public lands in much of the lynx DPS. The USFS, Bureau of Land Management (BLM), NPS, and the Service developed a Lynx Conservation Assessment and Strategy (LCAS) (Ruediger
et al.
2000, entire) using the best available science at the time specifically to provide a consistent and effective approach to conserve lynx and lynx habitat on Federal lands (Ruediger
et al.
2000). The overall goals of the LCAS were to recommend lynx conservation measures, to provide a basis for reviewing the adequacy of USFS and BLM land and resource management plans with regard to lynx conservation, and to facilitate conferencing and consultation under section 7 of the Act. The LCAS identifies an inclusive list of 17 potential risk factors for lynx or lynx habitat that may be addressed under programs, practices, and activities within the authority and jurisdiction of Federal land management agencies. The risks identified in the LCAS are based on effects to either individual lynx, lynx populations, or both, or to lynx habitat. Potential risk factors the LCAS addresses that may affect lynx productivity include: timber management, wildland fire management, recreation, forest/backcountry roads and trails, livestock grazing, and other human developments. Potential risk factors the LCAS addresses that may affect lynx mortality include: trapping, predator control, incidental or illegal shooting, and competition and predation as influenced by human activities and highways. Potential risk factors the LCAS addresses that may affect lynx movement include: highways, railroads and utility corridors, land ownership pattern, and ski areas and large resorts. Other potential large-scale risk factors for lynx addressed by the LCAS include: fragmentation and degradation of lynx refugia, lynx movement and dispersal across shrub-steppe habitats, and habitat degradation by nonnative and invasive plant species.

The LCAS used the best available information at the time to ensure the appropriate mosaic of habitat is provided for lynx on Federal lands. Although the LCAS was written specifically for Federal lands, many of the conservation measures are pertinent for non-Federal lands. To facilitate project planning and allow for the assessment of the potential effects of a project on an individual lynx, the LCAS directs Federal land management agencies to delineate Lynx Analysis Units (LAUs). The scale of an LAU approximates the size of area used by an individual lynx (25 to 50 mi
2
(65 to 130 km
2
)). The LCAS recognizes that LAUs will likely encompass both lynx habitat and other areas (
e.g.,
lakes, low elevation ponderosa pine (
Pinus ponderosa
) forest, and alpine tundra). Habitat-related standards the LCAS provides to address potential risks include: (1) If more than 30 percent of lynx habitat in an LAU is currently in unsuitable condition, no further reduction of suitable condition shall occur as a result of vegetation management activities by Federal agencies; (2) within an LAU, maintain denning habitat in patches generally larger than 5 ac (2 ha), comprising at least 10 percent of lynx habitat; (3) maintain habitat connectivity within and between LAUs; (4) management actions (
e.g.,
timber sales, salvage sales) shall not change more than 15 percent of lynx habitat within an LAU to an unsuitable condition within a 10-year period; (5) pre-commercial thinning will only be allowed when stands no longer provide snowshoe hare habitat; (6) on Federal lands in lynx habitat, allow no net increase in groomed or designated over-the-snow routes and snowmobile play areas by LAU.

With the listing of the lynx in 2000, Federal agencies across the contiguous United States range of the lynx were required to consult with the Service on actions that may affect lynx. The LCAS assists Federal agencies in planning activities and projects in ways that benefit lynx or avoid adverse impacts to lynx or lynx habitat (Ruediger
et al.
2000). If projects are designed that fail to meet the standards in the LCAS, the biologists using the LCAS would arrive at an adverse effect determination for lynx.

A Conservation Agreement between the USFS and the Service (U.S. Forest Service and U.S. Fish and Wildlife Service 2000) and a similar Agreement between the BLM and the Service (Bureau of Land Management and U.S. Fish and Wildlife Service 2000) committed the USFS and BLM to use the LCAS in determining the effects of actions on lynx until Forest Plans were amended or revised to adequately conserve lynx. A programmatic biological opinion pursuant to section 7 of the Act analyzed and confirmed the adequacy of the LCAS and its conservation measures to conserve lynx and concluded that Forest Service and BLM land management plans as implemented in accordance with the Conservation Agreements would not jeopardize the continued existence of lynx (U.S. Fish and Wildlife Service 2000).

In 2005, the USFS and the Service renewed the conservation agreement (U.S. Forest Service and U.S. Fish and Wildlife Service 2005) because the original agreement had expired. In the 2005 agreement, the parties agree to take measures to reduce or eliminate adverse effects or risks to lynx and its occupied habitat pending amendments to Forest Plans. The LCAS is a basis for implementing this agreement (U.S. Forest Service and U.S. Fish and Wildlife Service 2005). The 2005 agreement was renewed on October 20, 2006, and expires December 31, 2010, unless renewed. The BLM continues to adhere to their original agreement although it expired in December 2004.

Lynx conservation depends on management that supports boreal forest landscapes of sufficient size to encompass the temporal and spatial changes in habitat and snowshoe hare populations to support interbreeding lynx populations or metapopulations over time. At the time it was written, the LCAS provided the highest level of management or protection for lynx. The LCAS conservation measures address risk factors affecting lynx habitat and lynx productivity and were designed to be implemented at the scale necessary to conserve lynx. This level of management is appropriate for Federal lands, because they account for the majority of high-quality habitat in the United States and also because the inadequacy of regulatory mechanisms to conserve lynx on these lands at the time was the primary reason for listing the lynx as a threatened species under the Act. Furthermore, new information has come to light since the LCAS was written concerning that should be taken

into account by land managers. For instance, Kolbe
et al.
(2007) and Bunnell
et al.
(2006) published information on the effects of snowmobiling on lynx, and Squires
et al.
(2006) documented the importance of multilayered stands as snowshoe hare habitat. Further, ongoing research in Minnesota and Maine has also resulted in information helpful to forming our understanding of lynx and snowshoe hare (
e.g.,
Moen
et al.
2004; Hoving
et al.
2005; Homyack
et al.
2007; Fuller
et al.
2007). In some regions of Wyoming, Washington and Maine, research continues. Thus, as new information becomes available, this information should be used in addition to that used in the LCAS.

The Forest Service considered some of the new information discussed above when it proposed to revise 18 Forest Plans under a programmatic plan amendment called the Northern Rocky Mountain Lynx Amendment (NRLA) (Forest Service 2007). Because of the new information, some of the LCAS standards were changed to guidelines because the Service had determined that some risk factors were not negatively affecting the U.S. lynx DPS as a whole. Since publication of the LCAS, lynx studied in the United States have been shown to use a variety of sites and conditions for denning. Lynx denning sites are not believed to be a limiting factor in Montana and Maine study areas (Service 2007, pp. 48-49). Further, earlier assessments also concluded that in most geographic areas, denning habitat was not likely limiting to lynx, and existing forest plan direction would not result in adverse effects (Hickenbottom
et al.
1999). Likewise, after evaluating Bunnell
et al.
(2006, entire) and Kolbe
et al.
(2007, entire), we determined that the best information available did not indicate that compacted snow routes increase competition from other species to levels that adversely impact lynx populations in the NRLA area (Service 2007, pp. 55). Finally, since the LCAS was written, new information revealed the importance of multi-storied stands for lynx (Squires
et al.
2006). On the basis of this information, the Forest Service included a standard for conserving these multi-storied stands in the NRLA. This LCAS does not contain this standard.

In addition to diverging from the standards in the LCAS because of new information, the NRLA also deviated from the LCAS by allowing additional fuels reduction projects in areas within the wildlands-urban-interface (WUI). In our analysis of this action, we determined that even with these exceptions, the management in the NRLA would provide for the recovery of lynx in these areas by addressing the major reason we listed the lynx in 2000: The lack of guidance for conservation of lynx in Federal land management plans. Consultation under section 7 of the Act was completed for the NRLA in 2007, and it is now official land management direction for the National Forests that adopted it.

Criteria Used To Identify Critical Habitat

To identify areas containing the physical and biological features that are essential to the conservation of the lynx, we considered the concepts introduced in the recovery outline for the species (Service 2005, entire) and the analysis provided above concerning occupancy, evidence of reproduction, and the primary constituent elements laid out in the quantity and spatial arrangement necessary for the conservation of the species. We have also reviewed information from State, Federal, and tribal agencies, and information from academia and private organizations that have collected scientific data on lynx.

The focus of our strategy in considering lands for designation as revised critical habitat was on boreal forest landscapes of sufficient size to encompass the temporal and spatial changes in habitat and snowshoe hare populations to support interbreeding lynx populations or metapopulations over time. Individual lynx maintain large home ranges; the areas identified to have physical and biological features essential to the conservation of the lynx are large enough to encompass multiple home ranges. A secondary consideration is that, in addition to supporting breeding populations, these areas provide connectivity among patches of suitable habitat (
e.g.,
patches containing abundant snowshoe hares), whose locations in the landscape shift through time.

In proposing revised critical habitat for the lynx, we used the best scientific data available to evaluate areas that contained the PCEs in a spatial arrangement and quantity to provide the physical and biological features essential to the conservation of the species and that may require special management considerations or protection. In evaluating areas for proposal as revised critical habitat, we first determined the geographic area occupied by the species. We used 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 focused on records since 1995 to ensure that this 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 at the time of listing. Data that define the historic and current range of the lynx (
e.g.,
McKelvey
et al.
2000b, pp. 207-232; Hoving
et al.
2003, entire) 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 (64 FR 4483) and our clarification of findings (68 FR 40075). We base this conclusion on the fact that we do not have any information to suggest that lynx habitat has substantially contracted or expanded such that species' range at the time of listing would have been different than the current observations. Clearly, lynx-related research in the contiguous United States substantially increased after we published the 1998 proposal to list lynx, and this research provides additional information on which to base this proposed revised critical habitat designation. However, this is not a reflection of substantial changes to lynx habitat or the range of the lynx since 1995. 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 DNR 2005 website; 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 revised 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, p. 209)—(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 (
e.g.,
McKelvey
et al.
2006, entire) 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. However, we made an exception and accepted snow track data from Maine because of the stringent protocols used in confirming tracks as lynx and the minimal number of species in the area with which lynx tracks could be misidentified (McCollough 2006, entire).

The area occupied by the species was then overlaid with areas that contain boreal forest types. From this overlay we determined which areas contain the essential physical and biological features (
i.e.,
the primary constituent element (PCE) laid out in the quantity and spatial arrangement essential to the conservation of the species) by examining recent lynx records, evidence of breeding lynx populations, and presence of the boreal forest type that is currently occupied by lynx in each particular area and that provides 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, p. 427, 2000c, p. 33). Many of these populations in Canada are directly interconnected with United States' populations, and are likely a source of emigration into the contiguous United States; lynx from the contiguous United States are known to move into Canada. 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 for consideration as revised critical habitat.

In the North Cascades and Northern Rockies, the physical and biological 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, pp. 243-245; McAllister
et al.
2000, entire). Thus, we limited the delineation of revised critical habitat to lands above this elevation. Additionally, in the North Cascades, physical and biological features essential to the conservation of the lynx, the majority of the lynx records, and evidence of reproduction occur east of the crest of the Cascade Mountains. Therefore, in the Cascades we used the 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 the physical and biological features essential to the lynx or are not important for snowshoe hares. Therefore, east of the Continental Divide in the Northern Rockies we used National Forest and National Park Service (NPS) park boundaries to circumscribe proposed revised 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 border with Canada.

Delineating proposed revised lynx critical habitat boundaries in the Greater Yellowstone Area (GYA) was more challenging because it is a complex, high elevation ecosystem in which simply following elevation contours would be too broad in that they would encompass extensive areas of non-lynx habitat. Furthermore, the GYA has the least amount of available lynx-related research to assist us in delineating boundaries. Therefore, we drew the boundaries in the GYA around the majority of recent lynx records using a combination of National Forest boundaries and township lines to encompass the lynx habitat in this area.

As discussed above, we are seeking information on whether lands within the GYA contain physical and biological features essential to the conservation of the lynx because the habitat appears to be of lesser quality, and lynx occur at lower densities than the populations found in other units. Although lynx currently occupy the GYA (Murphy
et al.
2004, entire; J. Squires, Rocky Mountain Research Station, unpubl. data; S. Gehman, Wildthings Unlimited, unpubl. data), their presence has been at a naturally lower level compared to the other areas we are proposing as revised critical habitat. In the clarification of findings published in the
Federal Register
on July 3, 2003 (68 FR 40076), we concluded that habitat in this area is less capable than other areas of supporting snowshoe hares because it is naturally patchy and contains drier forest types, and because the GYA is disjunct from likely source populations. Within Yellowstone National Park, few lynx were detected during recent surveys (Murphy
et al.
2004, pp. 8-9) and hare densities were very low (Hodges and Mills 2005, pp. 5-6). Murphy
et al.
(2004, pp. 9-10) concluded that elevations and slope aspects cause lynx habitat in this area to be naturally highly fragmented resulting in low lynx densities. Few lynx were documented in the Wyoming Mountain Range in the southern portion of the ecosystem (Squires and Laurion 2000, pp. 343-345; Squires
et al.
2001, pp. 9-10). On study sites on the western edge of the Yellowstone ecosystem in Idaho, the subalpine fir vegetation series that comprises lynx and snowshoe hare habitat was found only in naturally small, discontinuous patches (McDaniel and McKelvey 2004, pp. 15-18). In this study area, few stands supported snowshoe hare densities similar to areas known to support lynx (McKelvey and McDaniel 2001, pp. 11-18).

If we determine, based on the best available scientific information and information obtained through public comments, that the GYA does not contain the physical and biological features essential to the conservation of lynx, we will not include it in the final rule. If we determine the area (or portions of it) does contain the features essential to the conservation of lynx, we intend to further refine the critical habitat boundary in the final rule based on improved mapping data and lynx occurrence data. Due to the fragmented mosaic nature of the GYA unit, it will by necessity contain patches of habitat that do not fit into the moist boreal forest types (
e.g.,
dry douglas fir, non-forest, or other habitats that do not support snowshoe hares, hereafter “matrix habitat”) usually considered lynx habitat. The inclusion of matrix habitat in this and other units is

necessary due to the inclusion of these areas in lynx home ranges and their use as travel habitat as lynx move between foraging and denning areas within their home ranges. Matrix habitat is included because it is interwoven with moist boreal forest types and, therefore, is used by lynx to travel unimpeded between foraging and denning areas within their home ranges. The important aspect of matrix habitat for lynx is that movement through it is not impeded.

We are also seeking information on whether the Kettle Range in north-central Washington is an area essential to the conservation of the lynx in the contiguous United States. Trapping records from the 1960s and 1970s show that the lynx population that once inhabited this area underwent dramatic swings in abundance going from high levels of harvest to low levels several times over two decades (McKelvey 1999, pp. 13-14). Since the 1970s, the area appears to have been unoccupied due to a lack of verifiable reports of lynx. Snow-tracking surveys conducted from 1992 to 1996 in the Kettle Range resulted in only two sets of tracks: one in 1991-1992 and one in 1995-1996. This indicates the lack of a reproducing population of lynx at that time. The Kettle Range currently has suitable lynx habitat (Koehler 2008) and the possibility that lynx occur does exist; however, the lack of verified occurrences since 1995 leads us to conclude that it is not likely to be occupied.

We are not currently proposing any areas outside the geographical area presently occupied by the species because we have determined that occupied areas are sufficient for the conservation of the species because these areas adequately address the concepts of representation, resiliency, and redundancy necessary for conservation of a species (Shaffer and Stein 2000). Resiliency of a species allows the species to recover from periodic disturbance. Areas are resilient if they are relatively large and contain particularly high-quality habitat or if their location or characteristics make them less susceptible to certain threats than other portions of the range. Resiliency of a species allows the species to recover from periodic disturbance. A species will likely be more resilient if large populations exist in high-quality habitat that is distributed throughout the range of the species in such a way as to capture the environmental variability found within the range of the species. The proposed revised critical habitat addresses the concept of resiliency because the total area of the five units covers a large geographic area (42,753 mi
2
(110,727 km2)), and because it contains the highest quality habitat in the United States. Redundancy of populations may be needed to provide a margin of safety for the species to withstand catastrophic events. The idea is to conserve enough areas of the range such that random perturbations in the system act on only a few populations. The proposed revised critical habitat addresses the concept of redundancy because it includes five units distributed across a broad geographic area. Catastrophic events that could affect all five units are extremely improbable. Adequate representation insures that the species' adaptive capabilities (often as indicated by genetic diversity) are conserved. Genetic representation is not an issue for lynx, because lynx across the range are similar and all share the same haplotypes (Rueness
et al.
2003, p. 71). Thus, we have determined that the five units contained in this proposed revised critical habitat address the concept of representation.

Lynx in the southern portion of their range exhibit metapopulation dynamics (
i.e.,
populations exist as semi-isolated subpopulations connected to other subpopulations by migration) (Thiel 1987, p. 94; McKelvey
et al.
1999, p. 24). The southern extensions of the North American lynx population that extend into the contiguous United States occur in marginal and naturally fragmented habitats and are likely dependent on migration from the core portion of the metapopulation in the Canadian taiga for genetic and demographic enrichment (McCord and Cardoza 1982, p. 729; McKelvey 1999, p. 232). Occupied areas within the current distribution of lynx (except for the reintroduced Colorado population) are the areas that have been most consistently occupied by reproducing populations (McKelvey 1999, pp. 211-232) and are the largest patches of suitable lynx habitat within the range of the DPS. Patches of lynx habitat outside of this occupied range are generally smaller and more isolated and have inconsistent records of lynx presence and reproduction, or no record at all (McKelvey 1999, pp. 211-232). Due to their high mobility, lynx may periodically occupy these areas; however, the lack of consistent occupation and reproduction means that these areas do not materially contribute to persistence of the DPS while the proposed areas clearly do.

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, pp. 39-45; McKelvey
et al.
2000b, pp. 211-232, 242-253; Hoving
et al.
2003, pp. 368-373). Within this broad distribution, the recovery outline (Service 2005, entire) 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 the sustainability of all core areas with the exception of the GYA is their connection with larger lynx populations in Canada. Each proposed revised critical habitat unit occurs within one of the areas identified as core in the recovery outline.

Relationship to Recovery Outline

We considered the lynx recovery outline (Service 2005) when developing this proposed revised critical habitat rule for lynx. However, the recovery outline and this proposed rule contain some differences. Recovery outlines are brief, internally-developed documents intended as preliminary strategies for the conservation of a listed species until a formal recovery plan is completed (Service 1989, entire; Service 1990, p. 6; National Marine Fisheries Service 2004, pp. 3.0-1 to 3.1-1). The lynx recovery outline was prepared by Service staff experienced in lynx conservation and recovery planning under the Act and two lynx experts from the USFS. The lynx recovery outline presented the understanding of historical and current lynx distribution, ecology, and population dynamics at the time it was written in 2005. 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 primarily on lynx records over time and evidence of reproduction. Additionally, the outline describes preliminary recovery objectives and actions.

The recovery outline and this proposed revised critical habitat rule used different standards and criteria. The recovery outline did not consider what areas contain the physical and

biological features that are essential to the conservation of lynx; rather, the preparers concentrated on distinguishing between areas with past or present lynx populations and those with lynx occurrence records that were unlikely to support reproducing populations. In designating critical habitat, we are required to determine those areas that contain the physical and biological features essential to the conservation of lynx within the geographical area occupied by the species. We have determined that areas that contain the physical and biological features essential to the conservation of lynx are those with verified records of lynx persistence into the present time and with verified evidence of reproduction. The areas identified as core in the recovery outline roughly coincide with the areas proposed as revised critical habitat with the following exceptions: (1) Mapping for the purposes of the recovery outline was done on a course scale without refined GIS layers, while the mapping done for the purposes of this proposed rule were more exact; and (2) further analysis shows that some areas considered core in the recovery outline (
e.g.,
the Kettle Range and New Hampshire) do not meet the criteria for core because they do not have long-term evidence of reproduction or current occupancy (see discussion below).

The recovery outline did not define which areas are essential to the conservation of lynx as is necessary for this revised proposed critical habitat designation. The criteria we used for determining areas essential to the conservation of lynx for this proposed revised critical habitat were more narrowly defined than those used for delineating the recovery areas in the lynx recovery outline; in particular, for critical habitat we focused closely on areas with reliable evidence of lynx reproduction since 1995. We used 1995 because of the Act's definition at 3(5)(A)(i) that occupied habitat include specific areas within the geographical area occupied by the species at the time it is listed. We believe that the documented lynx observations since 1995 best depict the range of the species both at the time it was listed (2000) and at the time of our clarification of findings (2003). Furthermore, the boundaries for the recovery areas were drawn on a gross scale compared to the proposed revised critical habitat boundaries. As a result, the proposed revised critical habitat units are subsets of five of the six areas preliminarily delineated as core in the lynx recovery outline.

In this revision, we do not propose revised critical habitat in one area the recovery outline defined as core: the Kettle Range in north-central Washington. The Kettle Range historically supported lynx populations (Stinson 2001, pp. 13-14). However, although boreal forest habitat within the Kettle Range appears of high quality for lynx, there is no evidence that the Kettle Range is currently occupied by a lynx population nor has it been for at least two decades (McKelvey 1999, p. 228; Koehler 2008, entire). Furthermore, it does not have recent (
i.e.
, 20 years) evidence of reproduction. Thus, it does not meet the criteria for “core” outlined in the recovery outline (Service 2005, p. 5). Snowtracking surveys conducted from 1992 to 1996 in the Kettle Range resulted in only two sets of tracks: one in 1991-1992 and one in 1995-1996 (McKelvey 1999, p. 228), indicating that although lynx may have been able to reach the range, they were unable to establish a population there. The above described attributes of the Kettle Range indicate that while this area may be considered a core area in the recovery outline, its importance for lynx conservation is less than those areas that we consider essential for the conservation of lynx due to their historic and recent history of reproduction and population occupation. We have made the preliminary determination that the area is not essential for the conservation of lynx; therefore, we do not propose to include it as revised critical habitat.

Likewise, the areas included in the recovery outline as core in western Maine and New Hampshire do not appear now to meet the criteria for core. No lynx were detected in New Hampshire and western Maine in the course of surveys done according to the standard lynx protocol for this region in 2005 (for New Hampshire) and 2006-2007 (in western Maine) (McCullough 2008, entire).

The recovery outline identified the Southern Rocky Mountains as a “provisional core” because of the current uncertainty that ongoing lynx reintroduction efforts will result in a self-sustaining lynx population. Native lynx were functionally extirpated from their historic range in Colorado and southern Wyoming in the Southern Rocky Mountains by the time the lynx was listed in 2000. In 1999, the State of Colorado began an intensive effort to reintroduce lynx. Initial results of this reintroduction were encouraging, with documented rates of reproduction similar to other lynx populations in the DPS (Shenk 2007, pp. 12-13). However, subsequent monitoring indicates that rates of reproduction have fallen in recent years, with zero reproduction detected for 34 females with radio collars in 2007 (Shenk 2007, p. 13). Although it is still too early to determine whether the introduction will result in a self-sustaining population, the reintroduced lynx have produced kittens and now are distributed throughout the lynx habitat in Colorado and southern Wyoming. These animals are not designated as experimental under section 10(j) of the Act. Although Colorado's reintroduction effort is an important step toward the recovery of lynx, we do not propose habitat in the Southern Rockies for revised designation because of the current uncertainty that a self-sustaining lynx population will become established. Determination of establishment will be based on the maintenance of a stable or naturally oscillating population structure composed of breeding individuals derived from wild mating and births (rather than introduced animals). A population that has demonstrated robustness to natural fluctuations due to oscillations in prey abundance is key to determining that they are established.

Many areas within the contiguous United States contain varying levels of individual lynx records with no evidence of persistent, reproducing lynx populations. Our review of many years of occurrence records reveals lynx records in areas with unsuitable habitats or snow conditions. However, we do not consider these areas capable of supporting lynx populations because they do not have the habitat or snow conditions suitable for lynx or snowshoe hare. Lynx occurrence in these areas is due to the population dynamics of lynx and their dispersal abilities that lead to lynx attempting to colonize new areas with little ability to support lynx reproduction. That is why we rely on a combination of consistent, verifiable evidence of lynx presence and reproduction, along with habitat characteristics to delimit critical habitat. Reliance on occurrence records alone, without consideration of reproduction and habitat variables, would lead to designation of large areas that may occasionally hold dispersing lynx for a short time, but due to their marginal nature and lack of sufficient food supply, will not support lynx reproduction and so do not contribute to lynx conservation. It is unlikely that these areas support undocumented, persistent populations of lynx because the forest types, snow conditions, and snowshoe hare populations are absent or are of such marginal condition due to

natural fragmentation that their ability to support lynx is minimal. In many cases these areas also support populations of bobcats, a species that excludes lynx from areas with low snow accumulation and act as a general indicator of habitat that cannot support lynx. Most of the records in these areas are likely a result of wide-ranging dispersal events through less suitable habitats that are mostly disjunct from areas that contain persistent lynx populations. Our recovery outline defines these areas as secondary or peripheral (see Service 2005, p. 21 for a map of core, secondary, and peripheral areas), and their role in sustaining persistent lynx populations is unclear. Such areas may provide habitat to dispersing lynx, especially when populations are extremely high and some of these animals may eventually settle in areas capable of supporting lynx populations. Areas delineated as secondary or peripheral in the lynx recovery outline are not included in our proposed revised critical habitat designation because they lack evidence of reproducing lynx populations and they lack large areas of contiguous habitat required to support populations. During natural lynx population fluctuations, these peripheral areas are likely to be the last areas to be colonized by excess lynx and the first to lose lynx as populations recede. We expect the areas in the proposed revised units to maintain lynx populations through natural population lows and serve as source populations for secondary areas as populations expand. We expect the areas in the proposed revised units will support lynx through cyclic population fluctuations, the most crucial time being the population lows. We consider the proposed revised units as the areas essential to provide for the long-term conservation of lynx across its contiguous United States range, as it is these areas that will serve as source populations for secondary areas as the populations expand. For this reason, we have determined the units in this proposed revision contain the physical and biological features essential to the conservation of lynx while other areas do not.

We propose critical habitat on lands we have determined were occupied at the time of listing; currently support the most abundant, reproducing lynx populations in the contiguous United States; and contain the physical and biological features essential to the conservation of the lynx and that may require special management. The focus of our proposed critical habitat revision is on boreal forest landscapes of sufficient size to encompass the temporal and spatial changes in habitat and snowshoe hare populations necessary to support interbreeding lynx populations or metapopulations over time. Individual lynx maintain large home ranges; the areas proposed as revised critical habitat are large enough to encompass multiple home ranges. A secondary consideration is that, in addition to supporting breeding populations, these areas provide connectivity among patches of foraging habitat (
e.g.
, patches containing abundant snowshoe hares), whose locations in the landscape shift through time.

When determining proposed revised critical habitat boundaries within this proposed rule, we made every effort to avoid including water bodies (lakes, rivers, and streams) and developed areas such as buildings, paved areas, and other structures that lack the physical and biological features essential for the conservation of the lynx. The scale of the maps we prepared under the parameters for publication within the Code of Federal Regulations may not reflect the exclusion of such developed areas. Any such structures and the land under them inadvertently left inside critical habitat boundaries shown on the maps of this proposed rule have been excluded by text in the proposed rule and are not proposed for designation as revised critical habitat. Therefore, Federal actions involving these areas would not trigger consultation under section 7 of the Act with respect to critical habitat, unless the specific action would affect the primary constituent element.

Proposed Revised Critical Habitat Designation

We are proposing five units as revised critical habitat for the lynx. These areas occur in northern Maine, northeastern Minnesota, the Northern Rocky Mountains (northwestern Montana/northeastern Idaho), the North Cascades (north-central Washington), and the GYA (southwestern Montana, northwestern Wyoming). The areas are distributed across the known occupied range of the lynx in the contiguous United States, and are essential to the conservation of the species. The critical habitat areas we describe below constitute our current best assessment of areas that meet the definition of critical habitat for lynx. To better understand the location of these proposed areas, please see the associated maps found within this proposed rule or examine them at
http://mountain-prairie.fws.gov/species/mammals/lynx/.
The five proposed revised critical habitat units are: (1) Northern Maine unit; (2) Northeastern Minnesota unit; (3) Northern Rocky Mountains unit (northwestern Montana/northeastern Idaho); (4) North Cascades unit (north-central Washington); and (5) Greater Yellowstone Area (southwestern Montana, northwestern Wyoming).

Table 1.—Critical Habitat Units Proposed for the Canada Lynx

Critical habitat unit

Miles
2

Kilometers
2

1. Northern Maine
10,633
27,539

2. Northeastern Minnesota
8,226
21,305

3. Northern Rocky Mountains (ID/MT)
11,304
29,276

4. North Cascades (WA)
2,000
5,180

5. Greater Yellowstone Area (MT/WY)
10,590
27,427

Total
42,753
110,727

Table 2.—Critical Habitat Proposed for the Canada Lynx by Landownership and State (mi
2
/km
2
)

Federal
State
Private
Tribal
Other

Idaho
50/131
1/3
0/0
0/0
0/0

Maine
13/34
758/1,962
9,741/25,230
86/223
35/90

Minnesota
4,279/11,082
1,099/2,848
1,548/4,008
72/187
1,149/2,976

Montana
11,182/28,960
372/964
1,985/5,140
347/898
72/188

Washington
1,831/4,742
164/424
5/13
0/0
0.1/0.2

Wyoming
7,695/19,930
14/36
133/343
0/0
43/110

Total
25,050/64,879
2,408/6,237
13,412/34,737
505/1,308
1,299/3,364

We present brief descriptions of each critical habitat unit below.

Unit 1: Northern Maine [10,633 mi
2
(27,539 km
2
)]

Unit 1 is located in northern Maine in portions of Aroostook, Franklin, Penobscot, Piscataquis, and Somerset Counties. This area was occupied by the lynx at the time of listing and is currently occupied by the species. Lynx in northwestern Maine have high productivity: 91 percent of available adult females (greater than 2 years) produced litters, and litters averaged 2.83 kittens (Vashon
et al.
2005b, pp. 4-6). This area contains the physical and biological features essential to the conservation of the lynx as it is comprised of the primary constituent element and its components laid out in the appropriate quantity and spatial arrangement. This area is also important for lynx conservation because it is the only area in the northeastern region of the lynx's range within the contiguous United States that currently supports breeding lynx populations and likely acts as a source or provides connectivity for more peripheral portions of the lynx's range in the Northeast. Timber harvest and management is the dominant land use within the unit; therefore, special management is required depending on the silvicultural practices conducted (68 FR 40075). Timber management practices that provide for a dense understory are beneficial for lynx and snowshoe hares. In this area, other habitat-related threats to lynx are lack of an International conservation strategy for lynx, traffic, and development (68 FR 40075).

Unit 2: Northeastern Minnesota [8,226 mi
2
(21,305 km
2
)]

Unit 2 is located in northeastern Minnesota in portions of Cook, Koochiching, Lake, and St. Louis Counties, and Superior National Forest. In 2003, when we last formally reviewed the status of the lynx, numerous verified records of lynx existed from northeastern Minnesota (68 FR 40076, July 3, 2003). The area was occupied at the time of listing and is currently occupied by the species. Lynx are currently known to be distributed throughout northeastern Minnesota, as has been confirmed through DNA analysis, radio- and GPS-collared animals, and documentation of reproduction (Moen
et al.
2004, entire; Minnesota DNR 2005, entire; S. Loch, unpubl. data; Minnesota Department of Natural Resources, unpubl. data). This area contains the physical and biological features essential to the conservation of the lynx as it is comprised of the primary constituent element and its components laid out in the appropriate quantity and spatial arrangement. This area is essential to the conservation of lynx because it is the only area in the U.S. Great Lakes region for which we have evidence of recent lynx reproduction. It likely acts as a source or provides connectivity for more peripheral portions of the lynx's range in the region. Timber harvest and management is a dominant land use (68 FR 40075). Therefore, special management is required depending on the silvicultural practices conducted. Timber management practices that provide for a dense understory are beneficial for lynx and snowshoe hares. In this area, lack of an International conservation strategy for lynx, fire suppression or fuels treatment, traffic, and development are other habitat-related threats to lynx (68 FR 40075).

Specific sections of land encompassing a mining district in Minnesota known as the Iron Range are not included in this proposed revised designation because they do not contain the physical and biological features essential to the conservation of lynx. In much of the Iron Range, mining has removed all vegetation and much of this area was subsequently flooded. Areas that are still vegetated and not flooded are extensively fragmented by the mined areas and haul roads. We used the “GAP Land Cover—Tiled Raster” dataset (Minnesota Department of Natural Resources 2002) to identify sections that are heavily influenced by mining activities. Areas described as “Barren” and “Mixed Developed” in the GAP dataset seemed to correspond to areas that were mined or extensively disturbed by mining-related activities (
e.g.,
service roads), based on aerial photos (National Agricultural Imagery Program 2003). Further inspection of the aerial photos indicate there are additional sections with extensive effects of mining, beyond that indicated by the GAP data, which is based on 10-15-year-old satellite imagery. These disturbed areas are not proposed as revised lynx critical habitat.

Unit 3: Northern Rocky Mountains [11,304 mi
2
(29,276 km
2
)]

Unit 3 is located in northwestern Montana and a small portion of northeastern Idaho in portions of Boundary County in Idaho and Flathead, Glacier, Granite, Lake, Lewis and Clark, Lincoln, Missoula, Pondera, Powell and Teton Counties in Montana. It includes the Flathead Indian Reservation, National Forest lands, and Bureau of Land Management (BLM) lands in the Garnet Resource Area. This area was occupied by lynx at the time of listing and is currently occupied by the species. Lynx are known to be widely distributed throughout this unit and breeding has been documented in multiple locations (Gehman
et al.
2004, pp. 24-29; Squires
et al.
2004a, pp. 7-10 and 2004b, pp. 8-10). This area contains the physical and biological features essential to the conservation of the lynx as it is comprised of the primary constituent element and its components laid out in the appropriate quantity and spatial arrangement. This area is essential to the conservation of lynx because it appears to support the highest density lynx populations in the Northern Rocky Mountain region of the lynx's range. It likely acts as a source for lynx and provides connectivity to other portions of the lynx's range in the Rocky Mountains, particularly the Yellowstone area. Timber harvest and management is a dominant land use (68 FR 40075); therefore, special management is required depending on the silvicultural practices conducted. Timber management practices that provide for a dense understory are beneficial for lynx and snowshoe hares. In this area, fire suppression or fuels treatment, lack of an International conservation strategy for lynx, traffic, and development are other habitat-related threats to lynx (68 FR 40075).

Unit 4: North Cascades [2,000 mi
2
(5,180 km
2
)]

Unit 4 is located in north-central Washington in portions of Chelan and Okanogan Counties, and includes BLM lands in the Spokane District. This area

was occupied at the time lynx was listed and is currently occupied by the species. This unit supports the highest densities of lynx in Washington (Stinson 2001). Evidence from limited recent research and DNA shows lynx distributed within this unit, with breeding being documented (von Kienast 2003, p. 36; K. Aubry, Pacific Northwest Research Station, unpubl. data; B. Maletzke, Washington State University, unpubl. data). Although there appear to be fewer records in the portion of the unit south of Highway 20, few surveys have been conducted in this portion of the unit. This area contains boreal forest habitat and the components essential to the conservation of the lynx. Further, it is contiguous with the portion of the unit north of Highway 20, particularly in winter when deep snows close Highway 20. The northern portion of the unit adjacent to the Canadian border also appears to support few recent lynx records; however, it is designated wilderness, so access to survey this area is difficult. This northern portion contains extensive boreal forest vegetation types and the components essential to the conservation of the lynx. Additionally, lynx populations exist in British Columbia directly north of this unit (E. Lofrothe, British Columbia Ministry of the Environment, unpubl. data). This area contains the physical and biological features essential to the conservation of the lynx as it contains the primary constituent element and its components laid out in the appropriate quantity and spatial arrangement. This area is essential to the conservation of lynx because it is the only area in the Cascades region of the lynx's range that is known to support breeding lynx populations. Timber harvest and management is a dominant land use; therefore, special management is required depending on the silvicultural practices conducted. Timber management practices that provide for a density understory are beneficial for lynx and snowshoe hares. In this area, Federal land management plans have not been amended to incorporate lynx conservation. The lack of an International conservation strategy for lynx, traffic, and development are other habitat-related threats to lynx (68 FR 40075).

Unit 5: Greater Yellowstone Area [10,590 mi
2
(27,427 km
2
)]

Unit 5 is located in Yellowstone National Park and surrounding lands in southwestern Montana and northwestern Wyoming. Lands in this unit are found in Gallatin, Park, Sweetgrass, Stillwater, and Carbon Counties in Montana, and Park, Teton, Fremont, Sublette, and Lincoln Counties in Wyoming. This area was occupied by lynx at the time of listing and is currently occupied by the species. The area contains the physical and biological features essential to the conservation of the lynx as it contains the primary constituent element and its components laid out in the appropriate quantity and spatial arrangement. The GYA is naturally marginal lynx habitat with highly fragmented foraging habitat. For this reason lynx home ranges in this unit are likely to be larger and incorporate large areas of non-foraging matrix habitat. In this area, fire suppression or fuels treatment, lack of an International conservation strategy for lynx, traffic, and development are other habitat-related threats to lynx (68 FR 40075). Therefore, special management is required depending on the fire suppression and fuels treatment practices conducted and the design of highway development projects.

Effects of Critical Habitat Designation

Section 7 Consultation

Section 7(a)(2) of the Act requires Federal agencies, including the Service, to ensure that actions they fund, authorize, or carry out are not likely to destroy or adversely modify critical habitat. Decisions by the 5th and 9th Circuit Court of Appeals have invalidated our definition of “destruction or adverse modification” (50 CFR 402.02) (see
Gifford Pinchot Task Force
v.
U.S. Fish and Wildlife Service,
378 F.3d 1059 (9th Cir. 2004) and
Sierra Club
v.
U.S. Fish and Wildlife Service et al.
, 245 F.3d 434, 442F (5th Cir. 2001)), and we do not rely on this regulatory definition when analyzing whether an action is likely to destroy or adversely modify critical habitat. Under the statutory provisions of the Act, we determine destruction or adverse modification on the basis of whether, with implementation of the proposed Federal action, the affected critical habitat would remain functional (or retain the current ability for the PCEs to be functionally established) to serve its intended conservation role for the species (Jones 2004, p. 3).

Section 7(a)(4) of the Act requires Federal agencies to confer with us on any action that is likely to jeopardize the continued existence of a proposed species or result in destruction or adverse modification of proposed critical habitat. Conference reports provide conservation recommendations to assist the agency in eliminating conflicts that may be caused by the proposed action. We may issue a formal conference report if requested by a Federal agency. Formal conference reports on proposed critical habitat contain an opinion that is prepared according to 50 CFR 402.14, as if critical habitat were designated. We may adopt the formal conference report as the biological opinion when the critical habitat is designated, if no substantial new information or changes in the action alter the content of the opinion (see 50 CFR 402.10(d)). The conservation recommendations in a conference report are advisory.

If a species is listed or critical habitat is designated, section 7(a)(2) of the Act requires Federal agencies to ensure that activities they authorize, fund, or carry out are not likely to jeopardize the continued existence of the species or to destroy or adversely modify its critical habitat. If a Federal action may affect a listed species or its critical habitat, the responsible Federal agency (action agency) must enter into consultation with us in most cases. As a result of this consultation, we document compliance with the requirements of section 7(a)(2) through our issuance of:

(1) A concurrence letter for Federal actions that may affect, but are not likely to adversely affect, listed species or critical habitat; or

(2) A biological opinion for Federal actions that may affect, and are likely to adversely affect, listed species or critical habitat.

An exception to the concurrence process referred to in (1) above occurs in consultations involving National Fire Plan projects. When we issue a biological opinion concluding that a project is likely to jeopardize the continued existence of a listed species or destroy or adversely modify critical habitat, we also provide reasonable and prudent alternatives to the project, if any are identifiable. We define “Reasonable and prudent alternatives” at 50 CFR 402.02 as alternative actions identified during consultation that:

• Can be implemented in a manner consistent with the intended purpose of the action,

• Can be implemented consistent with the scope of the Federal agency's legal authority and jurisdiction,

• Are economically and technologically feasible, and

• Would, in the Director's opinion, avoid jeopardizing the continued existence of the listed species or destroying or adversely modifying critical habitat.

Reasonable and prudent alternatives can vary from slight project modifications to extensive redesign or relocation of the project. Costs associated with implementing a

reasonable and prudent alternative are similarly variable.

When we issue a biological opinion concluding that a project is not likely to jeopardize a listed species or adversely modify critical habitat, but may result in incidental take of listed animals, we provide an incidental take statement that specifies the impact of such incidental taking on the species. We then define “Reasonable and Prudent Measures” considered necessary or appropriate to minimize the impact of such taking. Reasonable and prudent measures are binding measures the action agency must implement to receive an exemption to the prohibition against take contained in section 9 of the Act. These reasonable and prudent measures are implemented through specific “Terms and Conditions” that must be followed by the action agency or passed along by the action agency as binding conditions to an applicant. Reasonable and prudent measures, along with the terms and conditions that implement them, cannot alter the basic design, location, scope, duration, or timing of the action under consultation and may involve only minor changes (50 CFR 402.14). The Service may provide the action agency with additional conservation recommendations, which are advisory and not intended to carry binding legal force.

Regulations at 50 CFR 402.16 require Federal agencies to reinitiate consultation on previously reviewed actions in instances where we have listed a new species or subsequently designated critical habitat that may be affected and the Federal agency has retained discretionary involvement or control over the action (or the agency's discretionary involvement or control is authorized by law). Consequently, Federal agencies may sometimes need to request reinitiation of consultation with us on actions for which formal consultation has been completed, if those actions with discretionary involvement or control may affect subsequently listed species or designated critical habitat.

Federal activities that may affect lynx or its designated critical habitat require section 7 consultation under the Act. Activities on State, Tribal, local, or private lands requiring a Federal permit (such as a permit from the U.S. Army Corps of Engineers under section 404 of the Clean Water Act (33 U.S.C. 1251
et seq.
) or a permit from us under section 10 of the Act) or an activity involving some other Federal action (such as funding from the Federal Highway Administration, Federal Aviation Administration, or the Federal Emergency Management Agency) are subject to the section 7 consultation process. Federal actions not affecting listed species or critical habitat, and actions on State, Tribal, local, or private lands that are not federally funded, authorized, or permitted, do not require section 7 consultation.

Application of the “Adverse Modification” Standard

The key factor related to the adverse modification determination is whether, with implementation of the proposed Federal action, the affected critical habitat would continue to serve its intended conservation role for the species, or would retain its current ability for the primary constituent element(s) to be functionally established. Activities that may destroy or adversely modify critical habitat are those that alter the physical and biological features to an extent that appreciably reduces the conservation va

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A08-779. Public record. Not legal advice.