The effects of nesting success and mate fidelity on breeding dispersal in burrowing owls

Abstract

Understanding and describing the factors that affect avian breeding dispersal are critical for modeling population dynamics and designing conservation strategies. We investigated the hypothesis that dispersal probability and dispersal distance are affected by nesting success and mate fidelity with band–resight data (1998–2003) from burrowing owls (Athene cunicularia (Molina, 1782)) nesting in southern California. Most owls (167 of 253, 66%) remained near their initial nest (<100 m), and those that moved >100 m dispersed 472 ± 65 m (mean ± 1 SE; n = 86). Both female and male owls whose nests failed were more likely to disperse and dispersed longer distances than owls with successful nests. Failed nesting attempts were also associated with an increased probability of divorce, and divorce was related to increased dispersal probabilities and distances. Moreover, female and male owls tended to be more likely to disperse and to disperse greater distances following the death of a mate than those that remained paired. Although dispersal was related to mate fidelity, nesting success remained an important factor affecting dispersal even after controlling for the effects of mate loss. Our results suggest that nesting failure was the primary factor associated with dispersal probability and dispersal distance in burrowing owls in our population.