Résumé - CAFD

Wetland Use and Selection by Breeding Waterbirds in the Boreal Forest of Quebec, Canada.

Louis-Vincent Lemelin, Marcel Darveau, Louis Imbeau, Daniel Bordage.

Wetlands of remote forested landscapes of Quebec support numerous species of breeding waterbirds yet species-habitat associations remain poorly quantified. From 1990 to 2005, we conducted systematic helicopter surveys of breeding waterfowl and common loons (Gavia immer) across a 540,000-km2 forested region of Quebec. Data from this survey were used to investigate local habitat use and selection by waterbirds, based on a wetland classification system derived from digital forestry maps. Detailed indicated-breeding-pair (IBP) distributions were developed for broad aquatic, wetland, and shoreline habitat types. We also estimated selection ratios within groups of similar habitat types. Small (¡Ü8 ha), connected ponds were highly used and selected by five dabbling duck species and by wood duck (Aix sponsa), Canada goose (Branta canadensis), ring-necked duck (Aythya collaris), hooded merganser (Lophodytes cucullatus), common goldeneye (Bucephala clangula), and Barrow¡¯s goldeneye (B. islandica). Dabbling duck species, wood duck, and Canada goose made extensive use of streams (25¨C41% of all IBP). Community organization was mainly driven by openness of aquatic habitat and water movement, i.e., from lentic to lotic habitats. Failure to include streams in waterfowl surveys and habitat mapping could produce biased estimates of wetland habitat use and selection in the boreal forest.