Atlantic Co-Operative Wildlife Ecology Research Network

Birds Crossing Borders: Population Dynamics of Arctic Terns

Catherine Devlin, Ph.D. student

Populations of terns in North America have undergone several major fluctuations in the last two centuries. The number of Arctic Terns (Sterna paradisaea) breeding in the Gulf of Maine and Bay of Fundy region has been slow to recover in spite of 15 years of conservation efforts by groups in the US and Canada. This study will combine the current efforts in conservation and observation on the six main tern colonies in the region to examine the inter-colony movement of terns. An intensive immediate focus on Arctic Terns, in which research partners elsewhere in the Gulf of Maine and Bay of Fundy are particularly interested because Machias Seal Island (the main study location) is the regional centre of this population, has already begun; collaborators have been identified and have agreed to band and resight arctic terns in their colonies and to provide samples for genetic analysis.

The goal of this project is to determine if the terns nesting in this region are part of a regional metapopulation or if each island acts as an individual population, by comparing information on movement of individuals (from resighting of banded birds, using specially-designed field-readable bands) with measures of the genetic structure of the population, to test the hypothesis that movement between colonies is frequent and significant in this species. The banding study of nesting adults will investigate short term, year-to-year movement of the terns. The genetic analysis of feather samples taken from birds nesting on different islands will show the amount of gene flow among colonies over a longer time scale. Management strategies will be planned depending on the type and amount of movement shown. Little movement will indicate the importance of any decline on any island. If there is much movement of terns among colonies, then management strategies on one island could impact the terns nesting on other islands.

This project will involve the cooperation of ACWERN, the Gulf of Maine Seabird Working Group (whose members include U.S. Fish and Wildlife Service, Maine Department of Inland Fish and Game, National Audubon Society, Nature Conservancy and private individuals), and the Atlantic Canada Tern Working Group (whose members include Canadian Wildlife Service, Parks Canada, ACWERN, and private individuals).

Anderson, J.G.T. and C.M. Devlin. 1999. Restoration of a multi-species seabird colony.
Biological Conservation 90:175-181.

Anderson, J.G.T. and C.M. Devlin. 1996. Conservation biology and human ecology: umbrellas, flagships, and keystones. Human Ecology Review 3:238-242.