Sexual Differences in Gap-Crossing Ability of a Forest Songbird in a Fragmented Landscape Revealed Through Radiotracking

Abstract

Abstract We used radio telemetry to examine extraterritorial movements of female Hooded Warblers (Wilsonia citrina) breeding in small, isolated woodlots. Only 44% of the nine females tracked left their woodlots (n = 6 forays in total). Compared to males followed in the same fragments (Norris and Stutchbury 2001), females spent significantly less time off territory and traveled shorter distances across nonforested gaps. Unlike males in fragmented habitat and females in continuous forest, we found no evidence that females were actively seeking extrapair copulations. We conclude females are relatively more restricted to isolated fragments during the breeding season and suggest that the lack of extrapair copulation opportunity could contribute to female avoidance of fragmented habitat, resulting in a high number of unmated males. This study emphasizes the importance of examining the potential effects of fragmentation in both sexes.