Extraterritorial movements of a forest songbird in a fragmented landscape

Forest isolation resulting from fragmentation is thought to impede the move ment of forest songbirds. Because of the difficulty of tracking birds conti nuously however, few data exist documenting the influence of isolation and landscape features on avian movements. During the breeding season male Hood ed Warblers (Wilsonia citrine) leave their small (<2.5 ha), isolated forest patches to travel between forest fragments. We documented a total of 106 f orays (n = 20 males) and found that individuals traveled up to 2.5 km away from their resident forest patch, primarily to solicit covert extra-pair co pulations Forays occurred despite the absence of forested corridors connect ing fragments; even when corridors were present, males most often chose to fly directly across open fields. Resident patch size and distance to forest s visited were not correlated with the frequency of forays. The maximum dis tance males flew over open fields did not exceed 465 m and longer distances likely inhibit males from traveling outside their woodlots. If territorial establishment depends on the availability of extra-pair partners, then hig her degrees of isolation between forests could explain why some species avo id settling in extremely fragmented landscapes. Conservation efforts should limit isolation between forest stands, thereby preserving the ability of a nimals to move within fragmented landscapes during the breeding season.