Abstracts

Presented by Cindy Wood - Email: cindy.wood@canada.ca

Several sea ducks and both scaup species nest in remote regions of the Taiga Shield and Taiga Plains ecoregions, an area that straddles the tree line from Labrador to Alaska. Recent satellite telemetry studies have shown that these regions encompass core-breeding areas for all three species of scoters, and are also important breeding areas for Lesser and Greater scaup. However, there is a paucity of information on breeding habitat use and selection of those sympatric species which limits our ability to predict their distribution across the landscape, evaluate potential impacts of climate change or determine effective conservation actions. We conducted aerial surveys at six sites (20,000 km2 each) distributed within the Taiga Shield and Taiga Plains ecoregions, in Québec, Manitoba and the Northwest Territories during the pre-laying and early-laying period from 2017 to 2019. We used Natural Resources Canada’s CanVec database and DUC’s Hybrid Wetland Layer to extract a set of explanatory variables for habitat selection analysis at the scale of the survey plot (25 km2). Our results indicate that each species selected for different landscape features. Predicted densities for a given set of habitat features also varied markedly across sites, indicating that factors in addition to landscape-scale habitat features influence species abundance and distribution. Finally, we will evaluate inter-annual variation in habitat selection to determine how it responds to annual environmental conditions. Results from habitat selection models will provide a better understanding of landscape features important for breeding site selection in scoters and scaup. Habitat selection models will also provide a foundation for stratification of a potential future breeding ground survey as well as allow more robust estimates of population size and trend.