Behavioral switching in Magellanic woodpeckers reveals perception of habitat quality at different spatial scales

Abstract

The switching pattern between behavioral modes provides a mechanistic basis for understanding how animals perceive and memorize the habitat quality in their home ranges. We assessed if Magellanic woodpeckers (Campephilus magellanicus) move based on habitat quality at local (neighboring trees) and home range scales. We used state-space models to examine the relationship between remotely-sensed estimates of habitat quality (tree decay) and movement of adult woodpeckers tracked with GPS telemetry in southern Chile. Woodpeckers spent most time (> 80%) in the area-restricted search (ARS) mode in contrast to the exploratory transient mode, characterized by frequent directional displacements (> 50 m). The extent to which individuals switched between behavioral modes was related to habitat quality at different scales. Woodpeckers switched to and remained in the ARS mode when encountering moderate levels of heterogeneity in habitat quality. At very low or high heterogeneity levels, however, individuals switched to and remained in the transient mode, respectively. Likewise, as habitat quality declined locally and across home range, woodpeckers were more likely to adopt a transient mode. Although woodpeckers seemed to easily perceive and memorize habitat quality at different spatial scales, our results suggest that spatial memory will less effective under extreme levels of habitat heterogeneity.