AN EXPERIMENTAL STUDY OF NEST PREDATION IN A SUBTROPICAL WET FOREST FOLLOWING HURRICANE DISTURBANCE

摘要

We used artificial nest experiments to study rates and patterns of egg predation in subtropical wet and lower montane wet forest on the island of Puerto Rico. Levels of depredation were higher for ground nests than for elevated nests, but we found no difference in rates of egg predation between forest edge (5-50 m) and forest interior (100-250 m) nests. We quantified 25 forest vegetation variables surrounding ground and elevated, forest interior nests, and correlated nest success with these vegetation parameters. Utilizing discriminant function analysis, nest success was correctly classified in 59% of cases (for ground nests) using two vegetation variables (shrub density and vegetation in the 2.5-3.0 m foliage height class), and in 71% of cases (for elevated nests) using six vegetation variables (canopy cover, vegetation in the 0-0.5, 0.5-1.0, 1.0-1.5, and 3.0-4.0 m foliage height classes, and Cecropia tree density). Our data suggest that the absence of an induced edge effect is the result of the creation of canopy openings and early successional vegetative associations in a matrix across the forest following hurricane disturbance in 1989. Comparative data suggest that the high rates of egg predation recorded here may be typical for insular forest habitats.