2008-06-12_GENERAL DOCUMENTS - C1980007 (3)

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The aae of the forest stand does not seem as important for denning habitat as the amount of downed, woody debris available (Mowat et al. 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. In Washington, lynx used lodgepole • pine, Picea spp. (spruce), and Abies lasiocaipa (subalpine fir) forests older than 200 years with an abundance of downed woody debris for denning (Koehler 1990). A den site in Wyoming was located in a mature subalpine fir/lodgepole pine forest with abundant downed logs and a high amount of horizontal cover (Squires and Laurion 2000). A lynx den site found in Maine in 1999 was located in a forest stand in Picea rubra (red spruce) cover type that was logged in 1930 and again in the 1980s and is regenerating into hardwoods (Organ 1999). The site had a dense understory and an abundance of dead and downed wood. Site-scale habitat data, for the Colorado reintroduction program indicates that Engelmann spruce and subalpine fir are the most common forest stands used by lynx in southwestern Colorado (Shenk 2004). Shenk (2004, 2005a) further stated that in addition to the spruce/fir vegetation type, den sites were located in area with extensive downfall. Denning habitat must be in or near foraging habitat to be functional. The hunting range of females is restricted at the time of parturition, and their need to feed kittens requires an abundance of prey. Lynx, like other carnivores, frequently move their kittens until they are old enough to hunt with their mother. Multiple nursery sites are needed that provide kittens with overhead cover and protection from predators and the elements. Downed logs and overhead cover must also be available throughout the home range to provide security when lynx kittens are old enough to travel (Bailey 1974). Recruitment - Breeding occurs through March and April in the north (Quinn and Parker 1987). Kittens are born in May to June in south-central Yukon (Slough and Mowat 1996). The male is lynx does not help with rearing young (Eisenberg 1986). Slough and Mowat (1996) reported yearling females giving birth during periods when hares were abundant; male lynx may be incapable of breeding during their first year (McCord and Cardoza 1982). In northern study areas during the low phase of the hare cycle, few, if any, live kittens are born and few yearling females conceive (Brand and Keith 1979; Poole 1994; Slough and Mowat 1996). However, Mowat et al. (2000) suggested that in the far north, some lynx recruitment occurs when hares are scarce and this may be important in lynx population maintenance during hare lows. During periods of hare abundance in the northern taiga, litter size of adult females averages 4-5 kittens (Mowat et al. 1996). Koehler (1990) suggested that the low number of kittens produced in north-central Washington was comparable to northern populations during periods of love snowshoe hare abundance. In his study area, 2 radio-collared females had litters of 3 and 4 kittens in 1986 and 1 kitten in 1987 (the actual litter size of 1 of the females in 1987 was not determined) (Koehler 1990). Of the known-size litters in Washington, 1 kitten survived the first winter. In Montana, Squires and Laurion (2000) reported that 1 marked female produced 2 kittens in 1998. In 1999, 2 of 3 females produced litters of 2 kittens each. In Wyoming (Squires and Laurion 2000), 1 female produced 4 kittens in 1998, but snow tracking indicated that the kittens were not with the female in November and were presumed dead. The same female produced 2 • kittens in 1999. 6