Ecology of the Common Loon in marine and freshwater environments during the breeding season

         This study deals with the ecology of the Common Loon (Gavia immer, Brünnich 1764) during the breeding season in the coastal region of the Mingan islands archipelago, Québec. The Common Loon is a migrant aquatic bird, usually establishing breeding territories on inland freshwater lakes during the summer but wintering at sea (1). Thus, there is usually a temporal distinction between the utilization of these two different environments.

          Here I propose to examine the previously unstudied hypothesis that there is a simultaneous use of freshwater lakes and inshore marine waters during the breeding season by Common Loons. To confirm this I will study the daily movements between lakes and sea through radio-tracking of 10 nesting birds. They will be captured on their nesting lakes following the method developed by Evers (2). Habitat use and foraging behaviour at sea will be investigated as well and compared between the freshwater and marine environments. I will use time-activity budgets and diving schedules to compare the patterns of foraging behaviour. During the second year of sampling, long-term data loggers will monitor physiological modifications associated with foraging in freshwater and salt water. This project represents an opportunity to examine unknown aspects of the Common Loon’s ecology and in particular their use of the marine environment (3).

Literature cited

1.      McIntyre, J.W. and J.F. Barr 1997. Common Loon (Gavia immer). In The birds of North America, No. 313 (A.Poole and

       F.Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The Am. Ornithol. Union, Washington, D.C.

2.      Evers, D.C. 1994. Activity budgets of marked Common Loon (Gavia immer) nesting population. Hydrobiol. 279/280:415-

       420.

3.      Haney, J.C. 1990. Winter habitat of Common Loons on the continental shelf of the Southeastern United States. Wilson Bull.  

            102(2):253-263.

Arnaud Tarroux