Yellowstone Wolf Project: Annual Report 2010

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

At the end of 2010, at least 97 wolves (11 packs and 6 loners) occupied Yellowstone National Park (YNP). This is nearly the same size population as in 2009 (96 wolves) and represents a stable population. Breeding pairs increased from six in 2009 to eight in 2010. The wolf population declined 43% from 2007 to 2010, primarily because of a smaller elk population, the main food of northern range wolves. The interior wolf population declined less, probably because they augment their diet with bison. The severity of mange declined in 2010 and there was no evidence of distemper being a mortality factor as it was in 1999, 2005, and 2008. Pack size ranged from 3 (Grayling Creek) to 16 (Mollie’s) and averaged 8.3, slightly higher than in 2009 (7.1), but lower than the long-term average of 10 wolves per pack. Eight of the 11 packs reproduced (73%). The average number of pups per pack in early winter for packs that had at least one pup was 4.8, compared to the 2009 average of 3.8. A total of 38 pups in YNP survived to year end. Wolf Project staff detected 268 wolf kills in 2010 (definite, probable, and possible combined), including 211 elk (79%), 25 bison (9%), 7 deer (3%), 4 wolves (1%), 2 moose (<1%), 2 pronghorn (<1%), 2 grizzly bears (< 1%), 4 coyotes (1%), 2 ravens (<1%), and 10 unknown species (4%). The composition of elk kills was 43% cows, 25% calves, 18% bulls, and 15% elk of unknown sex and/or age. Bison kills included 4 calves, 6 cows, 7 bulls, and 8 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. Eighteen wolves from eight packs were captured and collared during 2010. At year end, 28 of the 97 (about 30%) known wolves in the park were collared. Wolf management activities included den site closures and four incidents of hazing habituated wolves, each of minor significance (yelling, horn blowing, etc.). Staff continued to manage wolf viewing areas in Slough Creek, Lamar Valley, and other places where wolves were frequently sighted. Wolf Project staff made 16,225 visitor contacts and counted about 38,000 people observing wolves; both figures were record highs for the program. Wolf Project public outreach included 248 talks (30% more) and 83 interviews (10% fewer). Additional information on wolves in Yellowstone is available at www.nps.gov/yell/naturescience/wolves.htm, www.greateryellowstonescience.org, and www.westerngraywolf. fws.gov.

Yellowstone Wolf Project: Annual Report 2010

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