Space use by white‐headed woodpeckers and selection for recent forest disturbances

Abstract

ABSTRACTWhite‐headed woodpeckers (Picoides albolarvatus) are important cavity excavators that recently have become the focus of much research because of concerns over population declines. Past studies have focused on nest site selection and survival but information is needed on factors influencing their space use when away from the nest. We examined space use by white‐headed woodpeckers during the nesting (May–Jul) and post‐nesting (Jul–Oct) periods and compared the role of environmental factors (e.g., landcover) and socio‐demographic factors (e.g., age, breeding success) in home range size and selection of location. Average size of 99% kernel home ranges was 125 ha (SD ± 59 ha; n = 19) in the nesting period and 137 ha (SD ± 70 ha; n = 30) in the post‐nesting period. Minimum convex polygons were generally comparable to or smaller than ranges reported from previous radio‐telemetry studies with this species. Although bird weight and age best explained variation in home range size compared to other factors, neither parameter estimate was significant in our models. Thus, even though weight and age were the most‐supported factors in our analysis, home range size was largely influenced by factors that we did not measure. We found that most woodpeckers selected home ranges within forest patches that had undergone a recent disturbance; these areas included forests that had recently been burned with prescribed fire by the United States Forest Service (82%) or subject to disease (16%). Most burned patches in our study were small (approx. 4.8 ha) and occurred within otherwise live forest but had nearly complete mortality of adult trees. We suggest that recent forest disturbances, especially mixed‐severity prescribed burns, may have been selected by white‐headed woodpeckers because they created snags for nesting and future studies should explore this hypothesis. Because home range size was variable and not linked with productivity, it should not be used as an indication of habitat quality without more detailed studies on causal factors that affect space use in this species. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.