Chapter 4 Lynx Gary

Three species of wild cats (felids) occur in the temperate forests of North America: the cougar (Fells concolor), bobcat (Lynx rufus), and lynx (Lynx canadensis). The cougar is found in both temperate and tropical forests from the mountains of southern British Columbia to the southern tip of South America, whereas the bobcat and lynx are restricted to the temperate zone of North America. Bobcats are common throughout a variety of habitats in the conterminous United States, southernmost Canada, and northern Mexico. The lynx, in contrast, occurs primarily in the boreal forests of Alaska and Canada, but its range extends south into the northern portions of the western mountains, where environmental conditions at high elevations support boreal forest habitats similar to those found in northern regions. The bobcat and lynx are both short-tailed cats, but the bobcat is smaller than the lynx and has relatively shorter legs and smaller paws. The lynx's short tail is completely tipped with black, whereas the bobcat's tail is generally longer and is barred with black only on the upper surface (Nowak and Paradiso 1983). The bobcat looks much like a house cat (Fells catus) in body form but is about two or three times larger. The lynx differs in body proportions, however, having relatively long legs and hind legs that are longer than the forelegs, giving it a stooped appearance (Quinn and Parker 1987). The winter pelage of the lynx is dense and has a grizzled appearance with grayish-brown mixed with buff or pale brown fur on the back, and grayish-white or buff-white fur on the belly, legs, and feet. Its summer pelage is more reddish to gray-brown. Male lynx are slightly larger than females, with total length averaging 85 cm compared to 82 cm, and weight averaging 10 kg for males and 8.5 kg for females (Quinn and Parker 1987). Both sexes have prominent ear tufts and a flared facial ruff. The paws of the lynx have twice the surface area of those of the bobcat (Quinn and Parker 1987). The lynx's long legs and broad paws enable it to negotiate the deep snows of the boreal forests and effectively hunt its principal prey, the snowshoe hare (Lepus americanus). The bobcat, lacking these features, is largely restricted to habitats where deep snows do not accumulate (Koehler and Hornocker 1991). Despite physiological and behavioral differences that may permit lynx and bobcats to exploit different niches (Parker et al. 1983), lynx apparently do not compete well with bobcats (Parker et al. 1983; Turbak 1991). Thus, habitat alterations that favor a northward range expansion by bobcats may not bode well for lynx, particularly in suboptimal habitats. The distribution and abundance of the lynx appears to be tied to that of the snowshoe hare. Both species are confined to northern forest environments (Hall 1981). Hares seek dense conifer thickets to feed on woody seedlings and saplings and to escape predators and extreme cold; lynx frequent these habitats in search of prey. When foraging, lynx select forested habitats where hares are plentiful and use this cover to stalk or wait for hares to appear. From the forested peninsulas of western Alaska to the eastern islands of Canada and in the mountains of the western United States, hares comprise 35-97% of the lynx diet (table 1). Although snowshoe hares are the primary food for lynx throughout its range, they also feed on mice, squirrels, grouse, and ptarmigan, especially during the summer months (McCord and Cardoza 1982). Hares not only determine where lynx are found but also influence how many lynx may occupy an area. This is dramatically illustrated in Alaska and central Canada, where hare populations cycle in abundance at varying amplitudes, with population