Behavioral development and habitat structure affect postfledging movements of songbirds

Abstract

ABSTRACTPostfledging survival of neotropical migrant songbirds has been linked to seasonal and annual changes in the environment and to individual condition. Understanding what influences variation in postfledging movements may provide insight into the differential value of habitat across life‐history stages. We conducted a radio‐telemetry study of postfledging ovenbirds (Seiurus aurocapilla; n = 45) and Acadian flycatchers (Empidonax virescens; n = 62) in mature‐forest fragments from 2012 to 2015 in Missouri, USA. We documented variability in behavior and space use and used generalized linear mixed models to evaluate the relationship of postfledging movement rates to individuals’ condition, temporal variables, and local habitat variables. We found effects of age and season on movement distances for both study species. Additionally, daily movements of fledgling ovenbirds were negatively related to understory foliage density, a characteristic previously linked to increased survival. Habitat features are useful in predicting the postfledging movements of ovenbirds. By including behavioral development (age) and season in movement models, we were able to isolate and detect habitat effects on movement of ovenbirds and Acadian flycatchers. We suggest researchers use models of daily movement to further strengthen resource quality hypotheses generated by habitat selection and survival studies. © 2016 The Wildlife Society.