Yellowstone wolf restoration

Science Center Objects

The National Park Service and U.S. Fish and Wildlife Service reintroduced wolves into Yellowstone National Park in 1995 and 1996. This study helps assess that population’s recovery and determine factors that affect the population, including diseases, intraspecific strife, and interactions with prey. The restoration has been very successful, and the population has persisted for more than 20 years despite it being affected by canine distemper, mange, and other diseases.  The Yellowstone wolves’ primary prey has always been elk, and we and other researchers have learned much about the interactions between the two species. One of the remaining questions was what factors affect the rate at which wolves encounter elk, a key factor in determining wolf hunting success rate.  Based on 46 wolf pack study periods from 2004 to 2012, only elk density influenced wolf encounter rate of elk, despite tests of season, snow depth, elk-group density, mean-elk group size, wolf-pack size and territory size.