Habitat Requirements of White-winged and Surf Scoters in the Mackenzie Delta Region, Northwest Territories

Abstract

... My thesis work focuses on learning more about the habitat requirements of white-winged and surf scoters in the Mackenzie Delta region. ... This summer, I conducted helicopter surveys of 220 wetlands in 31 randomly selected plots. Half of the plots were in the Delta, and half were in the upland habitat. Each wetland was surveyed twice in June for breeding pairs and twice in early August for broods. Wetlands were then classified as used or not used by pairs and broods of both species. In mid-August, I revisited a subset for used and non-used wetlands to collect water samples and data concerning characteristics of each wetland and its surrounding upland habitat. Initial results indicate that white-winged scoter pairs are more abundant than those of surf scoters in both Delta and upland regions. Pairs of both species occupy upland lakes more frequently than Delta lakes and seem to e more abundant on medium and large wetlands than on small wetlands. Although we observed 394 pairs of white-winged scoters and 68 pairs of surf scoters during the two breeding pair surveys, we observed only 68 white-winged scoter broods and 20 surf scoter broods. The broods were distributed approximately equally between Delta and upland lakes. I am currently compiling and analyzing data to verify these initial impressions and evaluate a habitat selection pattern. I will conduct a second field season next summer to compare predicted scoter distributions (based on results from 2001 data) and observed scoter distributions from independent surveys of new lakes in new plots.