Prospecting behavior and the influenceof forest cover on natal dispersal in aresident bird

Abstract

Dispersal behavior is key to population dynamics, yet little is known about the temporal, spatial, and social factors affecting natal dispersal. We studied natal dispersal behavior by intensively tracking a pair-breeding resident bird, the red-bellied woodpecker (Melanerpes carolinus), from fledging until permanent departure from the natal territory. Juveniles used a centrally based foray prospecting strategy. Woodpeckers made repeated forays into the surrounding landscape with subsequent daily returns to the natal area to roost. Prospecting individuals preferentially chose foray paths with greater forest cover. Woodpeckers eventually dispersed after repeated forays, and foray direction predicted dispersal direction. Birds that fledged earlier in the season and individuals from larger broods dispersed at a younger age than birds fledging later in the year and those from smaller broods. Females and smaller individuals dispersed farther than males and larger birds, but we identified no sex bias in dispersal direction. Prospecting and dispersal areas had more forest cover than areas beyond dispersal locations, indicating that fragmented landscapes may serve as barriers to dispersal. We provide evidence that juvenile birds used repeated forays to inform decisions about dispersal prior to permanent departure from the natal area. Intrinsic and social factors affected the distance and the age of dispersal, whereas habitat configuration affected direction of movement. © 2012 The Author.