FACTORS AFFECTING EGG PREDATION BY AMERICAN CROWS

Predation by Corvus brachyrhynchos on artificial duck nests in the prairie pothole region of SW Manitoba was higher on nests placed within home ranges than on nests placed at random locations outside of home ranges. However, artificial nests placed >700 m from crow nests, yet within home ranges, were relatively safe from predation. Predation was greater on upland than on overwater nests. Nests in low vegetation were most vulnerable to crows, but increases in cover height > 20-50 cm did not substantially reduce predation. -from Authors