Nest placement and mortality: Is nest predation a random event in space and time?

Abstract

In their recent article, Wilson and Cooper (1998) reported that Acadian Flycatchers (Empidonax virescens) selected nest trees nonrandomly, but that their choice of nest tree did not influence nest success. They concluded that nest predation appears random in time and space. However, we show their metric for nest tree use (% use - % available) is a poor indicator of nest tree selection. We reanalyzed their data using an appropriate selectivity index (from Chesson 1983), and found that nest tree selectivity was greater for nest tree species with higher daily nest survival rates. In general, nest predation, while it may appear unpredictable, may often be related to nest site characteristics.