Yellowstone National Park Wolves

2009 Executive Summary

At the end of 2009, at least 96-98 wolves in 14 packs (6 breeding pairs), 1 non-pack grouping, and 2 loners occupied Yellowstone National Park (YNP). This represents a 23% decline from 124 wolves in 2008. Despite the decline the number of breeding pairs did not change (6 in both 2008 & 2009). Intraspecific strife, food stress, and mange were likely cause for the decline. So far, there is no evidence of distemper as a cause of mortality, unlike previous population declines in 1999, 2005 and 2008. Pack size ranged from 3 (Lava Creek & Canyon) to 17 (Gibbon Meadows) and averaged 7.1, down from the long-term average of 9.8 wolves/pack. The average number of pups/pack in early winter was 1.8 for all packs, but 3.8 for packs that had pups, also down compared to the long-term average of 4.0 pups/pack.

Project staff detected 365 wolf kills including 302 elk (83%), 19 bison (5%), 17 deer (2%), 1 moose (<1%), 4 pronghorn (<1%), 1 bighorn sheep (<1%), 1 Canada goose (<1%), 1 bald eagle (<1%), 3 coyotes (<1%), 2 red foxes (<1%), 6 wolves (2%), and 8 unknown prey (2%). The composition of elk kills was 24% calves, 36% cows, 29% bulls, 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 were captured and collared in 11 packs. At year's end, 32 of 96 (35%) wolves were collared.

Wolf management activities included den site closures and hazing of habituated wolves. For the first time a wolf was killed near Old Faithful because it was food conditioned and a human safety threat. The Canyon pack denned within one mile of Mammoth Hot Springs and they were hazed from the developed area causing them to re-locate their den. Staff continued to manage wolf viewing areas in Lamar Valley and other hot spots where wolves were frequently sighted leading to 31,000 people observing wolves and 15,285 visitor contacts by Wolf Project staff. Wolf Project public outreach included 183 talks and 90 interviews to all types of groups and media including scientific conferences. (Information provided by Yellowstone staff)

Information provided by Yellowstone National Park

by John William Uhler

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