Yellowstone Wolf Project: Annual Report 2009

Smith, D; Stahler, D; Albers, E; McIntyre, R; Metz, M; Cassidy, K; Irving, J; Raymond, R; Zaranek, H; Anton, C; Bowersock, N

Summary At the end of 2009, at least 96 wolves in 14 packs, 1 non-pack group, and 2 loners occupied Yellowstone National Park (YNP). This represents a 23% decline from 124 wolves in 2008 but the number of breeding pairs (6) did not change. Intraspecific strife, food stress, and mange were the likely causes of the decline. No evidence of distemper as a cause of mortality has been found, unlike previous population declines in 1999, 2005, and 2008. Pack size ranged from 3 (Lava Creek and Canyon) to 17 (Gibbon Meadows) and averaged 7.1, down from the long-term average of 9.8 wolves per pack. The average number of pups per pack in early winter was 1.8 for all packs, but 3.8 for packs that had at least one pup, compared to the long-term average of 4.0 for packs with at least one pup. Wolf Project staff detected 365 wolf kills in 2009, including 302 elk (83%), 19 bison (5%), 17 deer (2%), 6 wolves (2%), 4 pronghorn (<1%), 3 coyotes (<1%), 2 red foxes (<1%), 1 moose (<1%), 1 bighorn sheep (<1%), 1 Canada goose (<1%), 1 bald eagle (<1%), and 8 unknown prey (2%). The composition of elk kills was 36% cows, 29% bulls, 24% calves, and 10% unknown sex and/or age. Bison kills included 7 calves, 4 cows, 3 bulls, and 5 unknown sex adults. Intensive winter and summer studies of wolf predation continued. Other research included population 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. Twenty-two wolves from 11 packs were captured and collared. At year end, 32 of the 96 (35%) known wolves in the park were collared. Wolf management activities included den site closures and hazing of habituated wolves. For the first time a wolf was intentionally killed in the park because it had become food conditioned and threatened human safety. The Canyon pack denned within one mile of Mammoth Hot Springs and was hazed from the developed area causing them to relocate their den. Wolf Project staff made 15,285 visitor contacts and counted 31,000 people observing wolves in Lamar Valley and other places where wolves were frequently sighted. Wolf Project public outreach included 183 talks and 90 interviews to all types of groups and media including scientific conferences. Additional information on wolves in Yellowstone National Park is available at www.nps.gov/yell/naturescience/ wolves.htm, www.greateryellowstonescience.org, and www.westerngraywolf.fws.gov.

Yellowstone Wolf Project: Annual Report 2009

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