Article

Assessment of a Western Canada Goose translocation: Landscape use, movement patterns and population viability

To provide new hunting opportunities in California and reduce nuisance and damage complaints in Nevada, 645 western Canada geese (Branta canadensis moffi tti) were trapped n moffifi near Reno, Nevada, and released on state wildlife areas around Humboldt Bay, California, 1987–1992. Numbers increased to about 3,200 by 1997 and an annual September sport hunt was initiated in 1998. The fl ock numbered about 1,500 individuals, 1999-2001. Farms used by the geese in recent years had more water bodies and were closer to roost sites than unused farms. Other landscape variables such as area/size and roads around farms were not signifi cantly different between used and unused farms. Sixty-eight of 630 (11%) banded birds were encountered outside the study area; 70% of the 68 emigrants were goslings (<1 year old) or yearlings (<2 years old). Twenty-one of 23 birds not killed when they were known to be outside the area returned to Humboldt Bay. Movements were in the north, northeast direction and were as far as British Columbia and Alberta, Canada, indicating that the small, resident Humboldt Bay fl ock is a part of the Pacifi c population of western Canada geese. A population viability analysis modeling the response of this small fl ock to harvest indicated stable numbers can be maintained with an annual harvest of ~200 birds. The model also predicts a rapid decline when harvests exceed 300 birds and a rapid increase in numbers when harvest levels were reduced. This study presents 1 of the few post-translocation assessments of a wildlife population.

Relationships

Items