Foraging Habitat and Chick Diets of Roseate Tern, Sterna dougallii, Breeding on Country Island, Nova Scotia

Breeding seabirds are threatened by human activities that affect nesting and foraging habitat.In Canada, one of the seabirds most at risk of extirpation is the Roseate Tern, Sterna dougallii. Althoughcritical nesting habitat has been identified for the Roseate Tern in Canada, its foraging locations and thediet of its chicks are unknown. Therefore, our goal was to determine the foraging locations and diet ofchicks of Roseate Tern breeding on Country Island, Nova Scotia, which is one of Canada’s two mainbreeding colonies. In 2003 and 2004, we radio-tracked the Roseate Tern by plane to locate foraging areasand conducted feeding watches to determine the diet of chicks. Roseate Tern foraged approximately 7 kmfrom the breeding colony over shallow water < 5 m deep. In both years, sand lance, Ammodytes spp., wasthe most common prey item delivered to chicks, followed by hake, Urophycis spp. Our results are consistentwith previous work at colonies in the northeastern United States, suggesting that throughout its range, thisspecies may be restricted in both habitat use and prey selection. The reliance on a specific habitat type andnarrow range of prey species makes the Roseate Tern generally susceptible to habitat perturbations andreductions in the availability of prey.

Jennifer C. Rock, Marty L. Leonard, and Andrew W. Boyne, Avian Conservation and Ecology-Ecologie et conservation des oiseaux 2(1): 4. [online]