Transplanting grizzly bears Ursus arctos horribilis as a management tool — results from the cabinet mountains, Montana, USA Original Research Article

A study of grizzly bears Ursus arctos horribilis in the Cabinet Mountains, Montana indicated that the future of the population was in jeopardy, and population augmentation was recommended. The US Fish and Wildlife Service (USFWS) issued an augmentation plan in 1987. The first of four projected transplants was completed in July 1990. The first transplanted grizzly bear was a 5-year-old female that weighed 71 kg. The first bear remained in the Cabinet Mountains following release and was monitored for 13 months before the radio collar was lost. This bear was visually located in the target area on 15 May 1992 approximately 19 km from the release site. Her home range from July 1990 through May 1992 encompassed 555 km2. Data regarding movements and habitat use were analysed and compared with native grizzly bears in the Cabinet Mountains. Trapping efforts in southeast British Columbia for additional bears to transplant were again conducted in 1991 and 1992. The effort resulted in the capture of eight different grizzly bears in 1991, but none met the sex and age criteria of 2-6-year-old females. Efforts in 1992 resulted in the capture of a second 71 kg 6-year-old female (bear 258) which was released at the same location as the first bear exactly 2 years later on 22 July 1992. Movements of bear 258 from July through November 1992 encompassed 388 km2 in the target release area. This second bear emerged with a single cub in May 1993 and was radio-monitored until July 1993 when it was found dead in the target release area. No trace of the cub was found although it had been seen with its mother in late June. The cause of death is as yet unknown pending completion of toxicology reports. A third subadult female bear (286) was captured in July 1993 and released in the target area where she has remained through October 1993. Transplanting of bears can be a valuable tool in the conservation of small bear populations worldwide.