An experimental analysis of nest predation in eastern deciduous forests
Nest predation exerts a major influence on the reproductive success of birds because it is the most important cause of nest loss. In this thesis, I studied how richness, density, and frequency of nests, and the fragmentation of forests through alterations of the landscape and forest structure affect nest predation levels. I estimated predation levels using over two thousand natural translocated nests and on artificial nests baited with quail eggs placed in large eastern deciduous forest fragments in southeastern Illinois during two breeding seasons (1992 and 1993). Overall, nest predation levels were random with respect to the several factors evaluated. The most prominent feature of the data was the high temporal and spatial variability (i.e., high heterogeneity) in nest predation levels, that may have obscured other biologically important patterns. The only consistently significant differences were between nests at different heights and times during the breeding season. Other factors (i.e. richness, density, and frequency of nests, distance to the forest-farm edge, richness and abundance of predators, distance to a geographical marker, and forest age since recovery from selective logging) had no significant effects on nest predation levels. The high heterogeneity of predation levels and our lack of knowledge of nest predators' behavior makes testing of hypotheses difficult.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign