Wolves

Wolves on Ellesmere Island, just south of the North Pole, survive in extreme cold during 24 hours of darkness per day from November through January, and survive in much higher temperatures during 24 hours of light per day from April through September. Partnering with other agencies, we use GPS radio collars applied to wolves during summer to examine wolf-pack movements on Ellesmere Island...

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...

When the wolf was listed as endangered, the last remaining mainland wolf population in the lower 48 states was in the Superior National Forest (SNF) of northeastern Minnesota. Since then, using radiocollaring and aerial tracking, we have studied the wolf population trend, factors influencing it, and prey species, white-tailed deer, moose, and beavers, affected by wolves. During winter 2018-2019...