Isle Royale winter study: 13 new wolves, 20 radio-collared moose

PRIL 30, 2019

by Kelley Christensen, Michigan Technological University

Michigan Technological University's 2019 Isle Royale Winter Study focuses on the implications of newly introduced wolves and the movements of newly collared moose.

Fifteen wolves. 2,060 moose. Extensive ice and deep, powdery snow. Michigan Tech researchers have released the annual Winter Study report. In its 61st year, the study is the longest running examination of a predator-prey relationship in the world.

The report chronicles the four-week research expedition to the island, where researchers track—by ski and plane—wolves and moose, collar moose, and catalogue the cascading effects of an ecosystem that has lacked a healthy population of apex predators for a number of a years.

New Tracks in the Snow

Prior to this fall and winter's wolf reintroductions, the wolf population on the remote island had remained at just two—a strongly bonded, but also highly inbred male-female pair—for three years. The moose population, lacking predation, expanded by an average of 19% each year during the past eight years since 2011, when the wolf population first dwindled to fewer than 10 individuals. Consequently, primary plant species in moose diets—balsam fir and watershield—dropped precipitously.

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