Synchronous Fluctuations of Thick-billed Murre (Uria lomvia) Colonies in the Eastern Canadian Arctic Suggest Population Regulation in Winter
The Auk 120(2): 2-70
000000017 60[vertical bar]ITLN[vertical bar]49[vertical bar]ITLY[vertical bar]Trends in populations of the thick-billed murre (Uria lomvia) at Prince Leopold Island and Coats Island, Nunavut, Canada, were investigated. Prince Leopold Island and Coats Island mark the opposite ends of the species range of the thick-billed murre in the eastern Arctic. Daily counts of fixed study plots over the period 1985-2000 revealed fluctuations at the 2 colonies to be well synchronized, with a positive correlation in changes in numbers from year-to-year with the mean mass of breeders during the first half of incubation. The similarity in fluctuations at the separate colonies indicates that population changes may be determined by events on the common wintering grounds. The common factor may be one that influences the availability of food during the nonbreeding period.