Journal Article

Factors Influencing Bald Eagle Densities in Northcentral Saskatchewan

Gerrard, Jon M., Dzus, Elston H.

1993

Overview

Bald eagle (Haliaeetus leucocephalus) densities vary throughout North America, but reasons for these differences are poorly understood and may be important for directing management practices. Thus, we evaluated the influence of forest nesting habitat and food abundance on the densities of bald eagles on 2 lakes in northcentral Saskatchewan, Canada. We found no evidence that nest-site availability influenced the number of eagles on either lake. Differences in the food supply were investigated both directly by netting fish, and indirectly, through information obtained from biological surveys at Besnard and Nemeiben Lakes. Cisco (Coregonus artedii), a key prey species for eagles, were more common and larger (P < 0.05) in Besnard Lake. Evidence from mineral content, plankton, benthic fauna biomass, and abundance of fish, support the contention that food abundance was the most important factor contributing to density differences of bald eagles between Besnard and Nemeiben Lakes. Food supply should be an integral part of any management plan aimed at protecting or enhancing bald eagle habitat.

• Publisher: The Wildlife Society,Wildlife Society,Blackwell Publishing Ltd
• Subject: Animal and plant ecology / Animal behavior / Animal nesting / Animal, plant and microbial ecology / Animals / Aves / Biological and medical sciences / Bird nesting / Birds / Birds of prey / Demecology / Eagles / Fish / Food supply / Forest habitats / Forest stands / Freshwater fishes / Fundamental and applied biological sciences. Psychology / Nesting / Nesting sites / Ornithology / Vertebrata