Effect of food, predation and climate on selection of breeding location by red-throated loons (Gavia stellata) in the high Arctic.

Abstract

The red-throated loon (Gavia stellata) is a circumpolar species. The purpose of this study was to examine adaptations of this species to environmental conditions in the high arctic. I found that the phenology of the loons in my study area was shorter than that of red-throated loons further south, and that this population tended to select nesting ponds much larger than in the south. I also found that pairs nesting near the ocean (within 9.0 km) were able to rear larger broods (2 chicks vs 1 chick) than pairs nesting far from the ocean (9.0-13 km). Finally, I found that pond size did not influence melting rate but that large ponds took longer to freeze. I also observed that 16% of loons moved their chick(s) to larger ponds when natal ponds began to freeze over. This supports the view that the use of large nesting ponds by these loons is an adaptation to the cold climate. (Abstract shortened by UMI.)