The foraging ecology of Glausous Gulls preying on the eggs and chicks of Thick-billed Murres ...

• Main Author: Gilchrist, H. Grant
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Arctic; Coats Island; Glaucous Gull; Greenland; Larus hyperboreus; Upernavik; Uria lomvia; uria
• Online Access: https://dx.doi.org/10.14288/1.0088327; https://doi.library.ubc.ca/10.14288/1.0088327

The glaucous gull (Larus hyperboreus) is a generalist predator with a circumpolar distribution. It commonly depredates the eggs and chicks of birds nesting in the Arctic, and often breeds in association with colonial nesting waterfowl and seabirds. The aim of this thesis was to examine how environmental factors constrained the ability of glaucous gulls to depredate cliff-nesting thick-billed murres (Uria lomvia), and to determine whether these constraints vary through time, in space, or between individuals. I also wanted to determine how changes in gull foraging constraints could affect the impact of gulls on murre reproductive success and population dynamics. This study was conducted from 1990-1992 at a murre colony on Coats Island, Canada, and in 1993 at colonies in the Upernavik region of Greenland. Based upon results from egg placement experiments and field observations of predation, gull foraging success was constrained by high murre nesting densities, collective murre defence, and the accessibility of ...