Nesting success and habitat preferences of forest-breeding migratory passerines in southeastern Ohio

In this study, several different spatial scales were utilized in studying the nesting success and habitat preferences of forest-breeding migratory passerines. Nesting success was studied to determine if a relationship existed between avian breeding productivity and the amount of forest fragmentation in southeastern Ohio. Microhabitat preferences of several forest-breeding songbirds were quantified in relation to two environmental components of breeding habitat to develop predictive models. One model predicted where preferred breeding habitat occurred, and the other predicted where nest sites were likely to be located.;Forest fragmentation was measured at several different spatial scales to determine if relationships between avian nesting success and fragmentation changed as spatial scale changed. For the spatial scales that were studied, the results suggested that the nesting success of most birds was not adversely affected by increased levels of fragmentation. Only the Acadian flycatcher was negatively affected by fragmentation. Parasitism by cowbirds was positively associated with the degree of forest fragmentation; however, the relatively low rate of observed parasitism had a minimal affect on overall reproductive success.;Extensive vegetation sampling was conducted at all of the nests located for this study, as well as at systematic locations throughout the study plots. Logistic regression models were developed to describe the vegetation characteristics most important in determining nest site habitat for several birds, and to predict where nest sites of these species were likely to occur. Generally, the resulting models performed well in correctly identifying nest site vegetation plots from a validation data set.;Associations between birds and geomorphologic variables were assessed within a geographic information system to develop species-specific habitat models for predicting where a given species was likely to occur and how much of the preferred habitat was available for that species. The models were based on species-specific microhabitat preferences for moisture and vegetation characteristics that can be predicted through the use of geomorphologic variables. The variables used in this study were slope, surface morphology, surface curvature, water flow accumulation, and an integrated moisture index. The models were tested on an independent data set and performed well.