Published: June 2001
Publication number: WDFW 735
Author(s): Derek W. Stinson
The lynx (Lynx canadensis) is the rarest of three cat species native to Washington probably numbering fewer than 100 individuals in the state. Lynx have large feet and long legs that give them a competitive advantage in deep snow over other carnivores that might otherwise compete for habitat and prey. Lynx are largely dependent upon a single prey species, the snowshoe hare, but they also eat red squirrels, small mammals, birds, and carrion. Lynx are primarily associated with subalpine and boreal forest types in the mountains of north-central and northeastern Washington, and formerly occurred in the southern Cascades. Topographic relief gives these forests a patchy distribution which in turn affects their potential to support lynx.
Across most of their range in northern boreal forests, lynx undergo cyclic changes in abundance that lag 1 year behind snowshoe hare population cycles. This 10-year cycle in snowshoe hare abundance may occur in Washington with a reduced amplitude, but it has not yet been clearly demonstrated. The lynx's response to the hare cycle produces pulses of dispersing individuals that may travel long distances in search of suitable habitat. At these times, some lynx may immigrate to Washington from larger populations in British Columbia and Alberta. Immigration from northern populations, and dispersal between subpopulations in Washington may be essential to the long-term viability of Washington's lynx population.
Prior to 1947, lynx in Washington were classified a "predatory anima" with a bounty of $5. Lynx were trapped or hunted until 1991 when a decline was readily apparent. It now seems clear that the lynx population in Washington could not sustain perennial exploitation due to the fragmented nature of subalpine-boreal habitats, low density of snowshoe hares, and variable quality of habitat through time. The lynx was listed as a state threatened species in 1993, and became a Threatened species under the federal Endangered Species Act (ESA) in April 2000.
The major factors affecting habitat and the lynx population include forest management, fire and fire suppression, insect epidemics, and management of lynx harvest and habitats in southern British Columbia. Lynx are relatively tolerant of human activity, but recreational developments and roads with high traffic volumes may affect lynx movements. Anecdotal observations have fueled speculation that snow compaction on forest roads and trails may affect the degree to which lynx must compete with coyotes and other carnivores, but few data exist from which to draw conclusions about the affect on lynx.
Most of the lynx habitat in 6 Lynx Management Zones is on federal lands (~92%), and almost 40% is in wilderness, parks and other reserves. Petitions to list the lynx under the ESA, and the subsequent listing increased attention on lynx. The large proportion of habitat in national forests provides the opportunity for the U. S. Forest Service to manage for lynx at the ecosystem scale. The understanding of lynx harvest management has improved in recent years, providing British Columbia and Alberta the ability to prevent overharvests that could reduce the frequency of immigration to Washington. These factors may improve the prospects for the recovery of lynx populations in Washington.
Meaningful population based recovery objectives are not possible to formulate at this time due to the rudimentary knowledge of lynx population dynamics in southern boreal forests. Interim objectives to down-list the lynx to Sensitive involve consistent occupancy of most of the habitat (>75% of lynx analysis units) capable of supporting reproductive populations. Recovery objectives and maps will be revised as new information becomes available about the habitat and populations of lynx and hare in Washington.
Stinson, D. W. 2001. Washington state recovery plan for the lynx. Washington Department of Fish and Wildlife, Olympia, Washington. 78 pp. + 5 maps.
Draft documents are provided for informational purposes only. Drafts may contain factual inaccuracies and may not reflect current WDFW policy.