Isle Royale wolf project researchers document summer predation

Dec 2, 2019

ISLE ROYALE NATIONAL PARK--   Researchers are releasing summer predation data from Isle Royale National Park. 

Wolf project technicians Megan Petersohn (left) and Cara Ratterman (right) sample wolf scat detected at wolf GPS cluster site, spring 2019, on Isle Royale.
Credit Tyler Petroelje / SUNY-ESF

National Park Service, State University of New York – College of Environmental Science and Forestry and Michigan Technological University biologists monitored wolves introduced to the island in the fall and winter of 2019. It’s the first time wolf predation has been studied during snow-free periods.

Between May and October crews visited 381 sites and located the remains of 60 prey. Data indicates 54.5 percent of the remains were moose, demonstrating introduced wolves had few problems adjusting to the larger prey. Of the moose preyed upon, 63.4 percent were calves. The study also revealed the importance of beaver and snowshoe hare in wolves’ diets.

GPS data led to the discovery of 24 moose carcasses by investigators and volunteers associated with Michigan Tech that will assist their long-term research, specifically the reconstruction of moose population estimates over time.

The Park Service is investigating ecosystem change as the island adjusts to the return of predation, a key process in the dynamics of Isle Royale. The research will help the NPS evaluate the success of its management actions as the project continues over the next few years.