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Mr. Richard Beatty

St. Paul District

U.S. Army Corps of Engineers

190 Fifth Street East

St. Paul, Minnesota 55101
Dear Mr. Beatty:
This document transmits the U.S. Fish and Wildlife Service=s (Service) final biological opinion for Koochiching County/International Falls wastewater treatment project and its effects on the threatened Canada lynx (Lynx canadensis) in accordance with section 7 of the Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 et seq.). Your February 7, 2003, letter requested Service concurrence with a U.S. Army Corps of Engineers (Corps) determination that the proposed project may affect, but will not likely adversely affect the species and was received in our office on February 13, 2003. A complete administrative record of this consultation is on file in this office.
The District Court for the District of Columbia issued an order on December 26, 2002, that enjoins the Service from issuing any Awritten concurrence[s]@ that actions proposed by any Federal agencies Amay affect, but are not likely to adversely affect@ the Canada lynx. Until further notice, all consultations concerning effects to Canada lynx must be conducted in accordance with the direction of the Court. Specifically, any actions subject to consultation that may affect Canada lynx require formal consultation as described in 50 CFR 402.14. This requires the preparation of a biological opinion that addresses how the proposed action is expected to affect Canada lynx in order to complete the procedural requirements of section 7 of the Act.
Consultation History
In a letter dated June 10, 2002, the U.S. Fish and Wildlife Service agreed to prepare a Planning Aid Letter (PAL) for the Corps on three wastewater treatment projects in northern Minnesota. The Corps is preparing the environmental documents for the projects but is not responsible for their construction, design, or funding. The Corps is, however, the federal nexus for these projects and as such, has responsibility for determining potential effects on listed species in association with these projects.
One of the sewer projects is located in Koochiching County, east of International Falls. Since issuance of the PAL, new information has become available which indicates that the Canada lynx may occur in the area. Consequently, the Corps submitted a letter to the Twin Cities Field Office with a determination that the project may affect, but is not likely to adversely affect the species. Given the parameters of the lawsuit described above, formal consultation was initiated. Project plans and the Planning Aid Letter form the basis for this consultation.
If you have any questions or comments on this biological opinion, please contact Ms. Laurie Fairchild at (612) 725-3548, extension 214.

Dan P. Stinnett

Field Supervisor
The proposed project is located east of International Falls in the vicinity of Jackfish Bay, on the Minnesota side of Rainy Lake. The wastewater treatment system would serve approximately 250 residences currently using individual treatment systems. Many of these systems are located on bedrock along the lakeshore and do not function adequately. The proposed project will install approximately 20 miles of wastewater collection line and connect the lines to an existing treatment plant. The majority of the connecting lines (19 miles) will be buried underneath existing roadbeds and work will be conducted within existing road right-of-ways. Sections of pipeline scattered throughout the action area, totaling approximately one mile, will require tree and shrub removal. The project is proposed for initial construction in the summer of 2003 and will conclude in the summer of 2005.

Factors associated with temporary construction include:

Blasting for the Sewer Pipeline – Because the area geology consists of shallow soils over bedrock, blasting will be required to install the collection system in some areas. Directional boring will be used to cross waterbodies. The construction contract includes a maximum decibel level of 134dB and the noise generated by blasting may cause wildlife to temporarily avoid the action area. Blasting will be conducted periodically as the project progresses.
Wooded Right of Way Clearing and Maintenance – The action area is characterized by gently sloping ground moraine to irregular hilly terrain with localized steep ridges surrounded by open water and large marshes. Mixed-conifer forested areas exhibit medium density canopy with some shrub understory and herbaceous ground cover. Affected wooded areas are scattered throughout the proposed project area. A typical project segment would require clearing a 45-foot right-of-way during project construction. A 20-foot right-of-way would be maintained on a periodic basis by the City of International Falls to provide access to the pipeline if necessary. The sewer lines will directly impact less than one mile of forest habitat. Length of the impacted forested project segments will vary depending upon the individual site.

Species Distribution
The Canada lynx is a medium-sized cat distinguished from bobcats (Lynx rufus) by long tufts on their ears and a short, black-tipped tail (McCord and Cardoza 1982). The lynx’s long legs and large, well-furred paws make it highly adapted for hunting in deep snow. Critical habitat has not yet been designated for the threatened population of Canada lynx in the contiguous United States.

Life History

Lynx home range sizes vary from 8 to 800 square kilometers (3 to 300 square miles) and may generally be larger at the southern extent of their range (Saunders 1963; Brand et al. 1976; Mech 1980; Parker et al. 1983; Koehler and Aubry 1994; Apps 2000; Mowat et al. 2000; Squires and Laurion 2000). Lynx are capable of dispersing extremely long distances (Mech 1977; Washington Department of Wildlife 1993), and dispersal peaks when snowshoe hare (Lepus americanus) populations decline (Ward and Krebs 1985; Koehler and Aubry 1994; O’Donoghue et al. 1997; Poole 1997).

Snowshoe hares are the primary prey of lynx especially in the winter, comprising 35-97 percent of the diet throughout the range of the lynx (Koehler and Aubry 1994). Other prey species include red squirrel (Tamiasciurus hudsonicus), other small mammals and birds; lynx also eat carrion (Saunders 1963; van Zyll de Jong 1966; Nellis et al. 1972; Brand et al. 1976; Brand and Keith 1979; Koehler 1990; Staples 1995; O’Donoghue et al. 1998a, b). In northern regions, when hare densities decline, the lower quality diet causes sudden decreases in the productivity of adult female lynx and decreased survival of kittens, which causes the numbers of breeding lynx to level off or decrease (Nellis et al. 1972; Brand et al. 1976; Brand and Keith 1979; Poole 1994; Slough and Mowat 1996; O’Donoghue et al. 1997). Relative densities of snowshoe hares at southern latitudes are generally lower than those in the north, but population dynamics of southern populations of snowshoe hare are poorly understood (Hodges 2000b).
Lynx populations are closely tied to snowshoe hare distribution. Snowshoe hares have evolved to survive in areas that receive deep snow (Bittner and Rongstad 1982). They prefer stands of conifers with shrub understories that provide forage, cover to escape predators, and protection during extreme weather (Wolfe et al. 1982; Monthey 1986; Koehler and Aubrey 1994). Early successional forest stages generally have greater understory structure than do mature forests and therefore support higher hare densities (Hodges 2000a, b), although openings in mature forests with dense understory also support hares (Buskirk et al. 2000a).
Cover is important to lynx when searching for food (Brand et al. 1976), although lynx often hunt along edges (Mowat et al. 2000). Lynx use large woody debris, such as downed logs, root wads, and windfalls, to provide denning sites with security and thermal cover for kittens (McCord and Cardoza 1982; Koehler 1990; Koehler and Brittell 1990; Mowat et al. 2000; Squires and Laurion 2000). Den sites may be located within older regenerating stands (>20 years since disturbance) or in mature conifer or mixed conifer deciduous (typically spruce/fir or spruce/birch) forests (Mowat et al. 2000). Downed logs and overhead cover must be available throughout the home range to provide alternative den and nursery sites, and security when lynx kittens are old enough to travel (Bailey 1974). Denning habitat must also be in or near foraging habitat.
Lynx breed in spring and produce up to five kittens per litter, with litter size affected by hare densities. During the low phase of the hare cycle, few if any live kittens are born (Brand and Keith 1979; Poole 1994; Slough and Mowat 1996). Litter sizes may be smaller in southern lynx range due to lower peak hare densities (Koehler 1990; Squires and Laurion 2000).
The most commonly reported causes of lynx mortality include starvation of kittens (Quinn and Parker 1987; Koehler 1990), and human-caused mortality, mostly fur trapping (Ward and Krebs 1985; Bailey et al. 1986). Significant lynx mortality due to starvation (up to two-thirds of deaths) has been demonstrated in cyclic populations of the northern taiga, during the first 2 years of hare scarcity (Poole 1994; Slough and Mowat 1996). Other forms of mortality include predation and highway collisions, although their significance to lynx populations is unknown (Brand and Keith 1979; Carbyn and Patriquin 1983; Ward and Krebs 1985; Bailey et al. 1986).
Buskirk et al. (2000a) suggested that when other hare predators, particularly coyotes (Canis latrans), can access lynx winter hunting areas via compacted snow they may compete for prey sufficiently to affect local lynx populations. Buskirk et al. (2000a) also suggested that direct killing by coyotes, bobcats, and mountain lions (Puma concolor) could affect lynx numbers where these competitors overlap substantially with lynx.
In Canada and Alaska, lynx populations undergo extreme fluctuations in response to snowshoe hare population cycles (Mowat et al. 2000). A lack of accurate data limits our understanding of lynx population dynamics in the contiguous United States at the southern periphery of their boreal forest range. Southern lynx populations may be naturally limited by the availability of snowshoe hares, as suggested by large home range size, high kitten mortality due to starvation, and greater reliance on alternate prey.

Status and Distribution

Canada lynx range is closely associated with the distribution of North American boreal forest inhabited by snowshoe hares (Agee 2000) and extends from Alaska, the Yukon and Northwest Territories south across the United States border in the Cascades Range and northern Rocky Mountain Range, through the central Canada provinces and down into the western Great Lakes region, and east to New Brunswick and Nova Scotia, Canada and south into the northeastern United States from Maine to New York (McCord and Cardoza 1982; Quinn and Parker 1987). In the western Great Lakes region, lynx range extends south from the classic boreal forest zone into the boreal/hardwood forest ecotone (Agee 2000; McKelvey et al. 2000). At its southern margins in the contiguous United States, forests with boreal features become naturally fragmented as they transition into other vegetation types and many patches cannot support resident populations of lynx and their primary prey species.

Canada lynx are solitary carnivores, generally occurring at low densities in boreal forest habitats. Within most of their range, Canada lynx densities and population dynamics are strongly tied to the distribution and abundance of snowshoe hare (Lepus americanus), their primary prey. However, this relationship may be muted or absent in more southern populations (Halfpenny

et al. 1982). Females may not reproduce during food shortages, and food availability directly correlates with the survival of young Canada lynx, with few kittens surviving when food is scarce (Koehler 1990). Kittens are born in May or June after a 60 to 74 day gestation period, and typically remain with their mothers until about 10 months of age.

Canada lynx may compete with canids, other felids, mustelids, and raptors for snowshoe hares and small mammals. Bobcat home ranges often exhibit elevational separation from those of Canada lynx, which are better adapted to deep snow. Bobcats are thought to displace Canada lynx where both felids are locally sympatric.
Minnesota has a substantial number of historical lynx reports, primarily trapping records and primarily from northeastern counties (Gunderson 1978, Mech 1980, McKelvey et al. 2000). Historically lynx were trapped in Minnesota through both population highs and lows, indicating that at least some animals may have persisted in a core resident population. Lynx habitat in northeastern Minnesota is contiguous with boreal forest lynx habitat in Ontario and hence, the continental lynx population. Henderson (1978), Mech (1980), McKelvey et al. (2000) suggested that the harvest peaks were influenced by influxes of lynx from Canada. Harvest records for Minnesota dating back to 1930 reveal approximate 10-year cycles, with highs in Minnesota of 330-400 lynx trapped in 1940, 1952, 1962, and 1973 (John Erb, personal communication 2003).1 Because lynx numbers did not increase in the early 1980s on the expected 10-year cycle (very few were harvested or reported observed), Minnesota closed its lynx season in 1984.
The Minnesota harvest trends are consistent with cyclical patterns in Ontario lynx harvest data. Ontario harvests were highest in 1926-27, 1962-63, and 1972-73 (Neil Dawson, personal communication 2002). Ontario harvest was then especially low in the 1990s “peak” (only one-fifth the 1972-73 harvest) following a period of very high prices for lynx pelts. The pattern of steeply declining peaks in the lynx harvest recorded from the 1970s to the 1990s in Ontario, however, occurred on a similar scale from the 1920s to the 1940s when fur prices were consistently much lower. Thus, the causes for reduced lynx harvests and likely abundance in Ontario in the early 1990s remain unexplained—as does the lack of anticipated lynx observation records in Minnesota in the early 1980s and 1990s. Snowshoe hare harvest data (the only available long-term index to hare abundance in Minnesota) show a very inconsistent pattern from 1941-2000. Hare abundance, as indicated by hunter harvests, peaked in the early 1940s and 1950s along with lynx harvests, but not in the early 1950s or 1960s. In contrast, hare harvest was double any previous year from 1977-1980, yet lynx did not increase. Hares remained at relatively low densities through the 1990s. At least in recent decades, lynx dynamics in the Great Lakes region may have been influenced more by immigration than local hare cycles (McKelvey et al. 2000). The role that changes in forest disturbance patterns (fire, blowdown, timber harvest) have had on Minnesota hare populations has not been studied.
Lynx are known to have reproduced in Minnesota during higher abundance phases in the 1970s (Mech 1973; 1980) and in 2002 (Minnesota Department of Natural Resources lynx observations database 2003). Based on large numbers of reported sightings since 2001 and genetic samples collected in 2002, lynx are experiencing a population peak in northeastern Minnesota (Minnesota Department of Natural Resources lynx observations database 2003). While recent records, including kitten observations, resolve that lynx are again reproducing and resident in Minnesota, the question of whether the population has previously or will in the future persist in Minnesota through cyclical population declines is uncertain. It is not clear whether Canada lynx persist in the state throughout the entire population cycle. Nevertheless, lynx that occur in Minnesota are members of a broad population that extends into and beyond Ontario in the boreal forest.


Status of the Species Within the Action Area
In 2002, Minnesota DNR personnel documented lynx tracks crossing Highway 11 and an adjacent bike trail in the NW 1/4 of Sec. 35, T71N, R23W (L. Peterson, Minnesota Department of Natural Resources, pers. comm. 2003), near the eastern edge of the action area. This and other observations of lynx in Koochiching County and elsewhere in northern Minnesota suggest that lynx may be present in the action area temporarily during or after project construction. The action area is small relative to the approximate size of lynx home ranges in Minnesota and is composed of a high proportion of developed areas (e.g., roads and residences).

Factors Affecting the Species Environment Within the Action Area

Risk factors associated with existing urbanization in the action area include residential development, recreation, and the impact of roads and trails. Roads, utility corridors, land ownership patterns, and developments may affect lynx movements. Risks of direct lynx mortality come from trapping, shooting, predator control, vehicle collisions, and competition or predation as influenced by human activities. Other large-scale risk factors are fragmentation and degradation of lynx refugia. Each of these potential risk factors may occur in the action area. The aforementioned risk factors will exist with the proposed project as well, and may slightly increase if more residential development occurs as a secondary result of the project.


The proposed wastewater treatment project may affect lynx by temporarily disturbing any animals that are traveling near the project sites during trenching activities within the roadways, blasting and tree/brush clearing activities. No new road or trail construction is proposed but short sections of pipeline, totaling less than one mile, would be buried cross-country and 20-foot right-of-ways would be maintained periodically in these areas for the life of the project. The greatest level of effect anticipated is that animals would temporarily move away from a project site when it is being constructed or maintained. Given the amount of urbanization associated with the project, it is unlikely that lynx den sites would be established in the area. Construction would begin in summer 2003 and be completed within two years. Effects of the project on lynx will be insignificant and no incidental take of any individuals is anticipated.


Cumulative effects include the effects of future State, tribal, local, or private actions that are reasonably certain to occur in the action area considered in this biological opinion. Future Federal actions that are unrelated to the proposed action are not considered in this section because they require separate consultation pursuant to section 7 of the Act.

The proposed wastewater treatment project may provide impetus for further development in the area. Potential impacts of increased development on lynx include loss of habitat for refugia and prey species, and increased human disturbance. Since the majority of the area serviced by the sewer project is already well populated and increased development is as likely to occur without the project (although on a potentially lower scale), the indirect effects from the project will be insignificant or discountable.


After reviewing the current status of Canada lynx, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, it is the Service’s biological opinion that the proposed Koochiching County/International Falls wastewater treatment project near Jackfish Bay is not likely to jeopardize the continued existence of the lynx. No critical habitat has been designated for this species; therefore, none will be affected.

Section 9 of the Act and Federal regulation pursuant to section 4(d) of the Act prohibit the take of endangered and threatened species, respectively, without special exemption. Take is defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt to engage in any such conduct. Harm is further defined by the Service to include significant habitat modification or degradation that results in death or injury to listed species by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering. Harass is defined by the Service as intentional or negligent actions that create the likelihood of injury to listed species to such an extent as to significantly disrupt normal behavior patterns which include, but are not limited to, breeding, feeding or sheltering. Incidental take is defined as take that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity. Under the terms of section 7(b)(4) and section 7(o)(2), taking that is incidental to and not intended as part of the agency action is not considered to be prohibited taking under the Act provided that such taking is in compliance with the terms and conditions of this Incidental Take Statement.
The Service does not anticipate the proposed action will incidentally take any Canada lynx. Reasonable and Prudent Measures and Terms and Conditions are not applicable because no incidental take is anticipated.

Section 7(a)(1) of the Act requires Federal Agencies to utilize their authorities to further the purposes of the Act by carrying out conservation programs for the benefit of endangered and threatened species. Conservation recommendations are discretionary agency activities to minimize or avoid adverse effects of a proposed action on listed species or critical habitat, to help implement recovery plans, or to develop information. As we do not anticipate any adverse effects of the proposed action on Canada lynx, no conservation recommendations are necessary.
This concludes consultation on the action outlined in your February 7, 2003, request for consultation for the Koochiching County wastewater treatment project near International Falls, Minnesota. As provided in 50 CFR 402.16, reinitiation of formal consultation is required where discretionary Federal agency involvement or control over the action has been maintained (or is authorized by law) and if: (1) the amount or extent of incidental is exceeded; (2) new information reveals effects of the agency action that may affect listed species or critical habitat in a manner or to an extent not considered in this opinion; (3) the agency action is subsequently modified in a manner that causes an effect to the listed species or critical habitat that was not considered in this opinion; or (4) a new species is listed or critical habitat designated that may be affected by the action. In instances where the amount or extent of incidental take is exceeded, any operations causing such take must cease pending reinitiation.

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1 Lynx were unprotected in Minnesota before 1976 and harvest data come from trapper report cards (bounties were paid for lynx from 1951-1964). From 1976-1983 lynx harvest seasons were set and data on hunting and trapping come from registrations.

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