We evaluated the effect of a flagged-stake marker on success of duck nests in the prairie pothole region of Canada, and whether abundance of American Crows (Corvus brachyrhynchos) influenced results. We marked 565 nests with flagged-stake markers and 573 in relation to natural objects (e.g., rock, tree, fence-post). We detected no difference in average daily survival rates between nests with flagged vs. natural markers (Xi?? = 3.37, 1 df, P = 0.07). Success rates averaged 10% for nests with flagged markers and 6% for nests with natural markers. The direction of the difference was consistent among areas and years (Xi?? = 19.9, 17 df, P = 0.28). We detected no correlation among areas and years between indices of American Crow abundance and differences in daily survival rates between nests with flagged markers and nests with natural markers (r = 0.02, 37 df, P = 0.91).
Additional publication details
Effect of a commonly-used nest marker on nest success of ducks in prairie Canada