Wintering ground effects on vital rates of white-winged scoters (Melanitta fusca) at Redberry Lake, Saskatchewan

Project Number: 35

Year Funded: 2005

Lead Institution(s): University of Saskatchewan

Project Lead: Cindy Swoboda

Email:

Collaborator(s): Ray Alisauskas (CWS), IWWR, DUC, SDJV, USask

Location: Saskatchewan

Focal Species: White-winged Scoter (Melanitta delgandi)

Project Description: North American White-winged scoter populations have declined markedly in the prairie parklands and boreal forests of Canada in the last four decades, raising concern and exposing the need to address specific priorities that include: estimation of survival and production rates, population delineation, and linkage of wintering areas to breeding areas. The causes for decline are uncertain, but likely involve a complexity of events occurring on both the wintering and breeding grounds. As events on these areas are not mutually exclusive, it is important to link breeding and wintering areas to address conservation issues. Stable isotope markers have been successfully used for this purpose in other avian species. We will use stable isotope analysis techniques to examine potential differences in vital rates of a nesting population of White-winged scoters in relation to winter origin at Redberry Lake, Saskatchewan. This site has the highest known density of breeding White-winged scoters and is considered a migrational divide as band recoveries from Redberry Lake have occurred on both the Atlantic and Pacific coasts. Nests are located on the islands in Redberry Lake and revisited every 7-10 days to determine fate and to band ducklings at hatch. Females were captured on the nest during mid-incubation during which time they were measured, nasal-marked, banded and sampled for blood and feathers.