The physiology of polar birds

Summary

Polar birds have always held a fascination for man, e.g. the movements of birds to and from the Arctic have heralded the start of spring and the end of summer, respectively, for many northern cultures. Yet, it is only within recent years that research has started to unfold the complex interaction between the physiology of the birds and the polar environment. The early studies concentrated on the breeding behaviour and ecology of the birds. Increasingly, researchers are investigating how the physiology of the birds has evolved and how it enables them to survive the polar environment. Coupled with this, the advent of new technology has meant that the physiology of many species can now be studied remotely in the wild.

Few bird species can survive for any length of time in the high latitude polar regions. Vuilleumier (1996) reported that up to 29 different species have been sighted between the high Arctic Ocean and the North Pole over a number of years. However, the number of species declined with increasing latitude, as did their absolute numbers. The most common species north of 83° N were the kittiwake (Rissa tridactyla), Ross's gull (Rhodostethia rosed), the ivory gull (Pagophila eburnea) and the fulmar (Fulmarus glacialis). In the Northern Hemisphere, breeding sites for birds are restricted to circumpolar land masses that extend typically up to around 80° N, of which the best known are the Canadian, Alaskan, Scandinavian and Russian Arctic areas and the islands of the North Atlantic Ocean. In the southern hemisphere, there are even fewer species, with no resident land birds at all on the continent of Antarctica.