Yellowstone Wolf Project: Annual Report 2012

Smith, D; Stahler, D; Stahler, E; Metz, M; Quimby, K; McIntyre, R; Ruhl, C; Martin, H; Kindermann, R; Bowersock, N; McDevitt, M

At the end of 2012, at least 83 wolves in 10 packs (6 breeding pairs) occupied YNP. This is approximately a 15% decline from the previous three years when wolf numbers had stabilized around 100 wolves. Breeding pairs declined 25% from eight the previous year to six in 2012. Wolf numbers have declined by about 50% since 2007 mostly because of a smaller elk population, the main food of wolves in YNP. The number of wolves living in the park interior has declined less, probably because they supplement their diet with bison. State-managed wolf hunts harvested 12 wolves that lived primarily in YNP when these animals moved into Montana, Idaho, and Wyoming. The severity of mange, a skin disease caused by non-native mites, continued to decline in 2012, although some packs still showed signs of the mite. There was no evidence of distemper being a mortality factor as it was in 1999, 2005, and 2008. Pack size ranged from 4 (Blacktail and Snake River) to 11 (Lamar Canyon, Cougar, and Yellowstone Delta) and averaged 10 which is the long-term average. Seven of 11 (64%) packs had pups. The average number of pups per pack in early winter (for packs that had pups) was 2.5, which is lower than previous years’ averages of 4.1 (2011) and 4.8 (2010). A total of 20 pups in YNP survived to the end of the year (14 fewer than in 2011). Project staff detected 255 kills (definite, probable, and possible combined) made by wolves in 2012, including 159 elk (62%), 32 bison (13%), 13 mule deer (5%), 2 whitetail deer (1%), 5 deer unknown species (2%), 4 pronghorn (2%), 2 moose (1%), 2 Canada geese (1%), 9 wolves (4%), 1 bighorn sheep (<1%), 1 otter (<1%), 1 grizzly bear cub (<1%), 1 coyote (<1%), and 23 unknown prey (9%). The composition of elk kills was 40% cows, 28% calves, 21% bulls, 4% yearlings, 4% adults of unknown sex, and 3% of unknown sex and age. Bison kills, which were recorded as the highest proportion of total kills since monitoring has been occurring, included 17 calves, 8 cows, 1 yearling, 1 bull, 2 adults of unknown sex, and 3 of unknown sex and age. Other research included genetics, disease, hunting behavior, spatial analyses of territory use, wolf pack leadership, multi-carnivore-scavenger interactions, breeding behavior, dispersal, and observations of wolf, grizzly bear, and bison interactions in Pelican Valley. During 2012, 19 wolves were captured and collared in 9 packs. At year’s end, 21% of the wolves living in YNP were collared. Other wolf-management activities included den site closures and several hazing events. Staff continued to manage wolf viewing areas in Slough Creek and Lamar Valley and other spots where wolves were frequently sighted, leading to a minimum estimate of 27,500 people observing wolves and 17,978 visitor contacts by wolf project staff. Wolf project public outreach included 280 educational talks and 89 interviews. Additional information on wolves in Yellowstone National Park is available at www.nps.gov/yell/naturescience/ wolves.htm, www.greateryellowstonescience.org, and www.fws.gov/mountain-prairie/species/mammals/wolf/.

Yellowstone Wolf Project: Annual Report 2012

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