Singing in the shade: song and song posts of northern cardinals near nesting Cooper's hawks

Animals may compensate for increased predation risk by changing the behaviours that make them vulnerable. In this study, we compared the singing and perching behaviours of northern cardinals (Cardinalis cardinalis L., 1758) living within 100am of nesting Cooper's hawks (Accipiter cooperii (Bonaparte, 1828)) with that of cardinals in similar control sites. Cardinals sang similar amounts at hawk nests and at control sites, but they sang from less exposed perches when near Cooper's hawk nests. These results suggest that singing from an exposed perch is both more dangerous and more effective for northern cardinals.