Dispersal of wolves (Canis lupus) in northeastern Minnesota, 1969–1989

Abstract

We examined the dispersal patterns of radio-collared wolves (Canis lupus) from 21 packs in the Superior National Forest, Minnesota, from 1969 to 1989. A total of 316 wolves (542 wolf-years) were captured, radio-collared, and followed during 21 years of radio-tracking; 75 were identified as dispersers. Both sexes dispersed equally. Of the adults, yearlings, and pups, 8, 75, and 16%, respectively, dispersed. Most dispersers left when they were 11–12 months old, only a few wolves dispersing as adults. Dispersal occurred mainly in February–April and October–November. Adults dispersed short distances into nearby territories, but yearlings and pups dispersed both short and long distances. Yearling and pup dispersal rates were highest when the wolf population was increasing or decreasing and low when the population was stable. Adults had the highest pairing and denning success. Yearlings had moderate pairing and low denning success, and pups had low pairing and denning success. Yearlings and pups that dispersed a short distance had a higher success of settling in a new territory, likely reflecting available vacancies in nearby territories. Thirty-five percent of the known-age wolves remained in their natal territory for >2 years; two wolves were known to have remained for >7 years. The relative weight of pups at capture apparently did not affect their age or success of dispersal or the tendency to disperse.