White‐Headed Woodpecker Nesting Ecology After Wildfire

Abstract

Within forests susceptible to wildfire and insect infestations, land managers need to balance dead tree removal and habitat requirements for wildlife species associated with snags. We used Mahalanobis distance methods to develop predictive models of white‐headed woodpecker (Picoides albolarvatus) nesting habitat in postfire ponderosa pine (Pinus ponderosa)‐dominated landscapes on the Fremont‐Winema National Forests in south central Oregon, USA. The 1‐km radius (314 ha) surrounding 45 nest sites was open‐canopied before fire and a mosaic of burn severities after wildfire. The 1‐ha surrounding nests of white‐headed woodpeckers had fewer live trees per hectare and more decayed and larger diameter snags than at non‐nest sites. The leading cause of nest failure seemed to be predation. Habitat and abiotic features were not associated with nest survival. High daily survival rates and little variation within habitat features among nest locations suggest white‐headed woodpeckers were consistently selecting high suitability habitats. Management activities that open the forest canopy and create conditions conducive to a mosaic burn pattern will probably provide suitable white‐headed woodpecker nesting habitat after wildfire. When making postfire salvage logging decisions, we suggest that retention of larger, more decayed snags will provide nesting habitat in recently burned forests.

Foraging plasticity by a keystone excavator, the white-headed woodpecker, in managed forests: Are there consequences for productivity?

“…Given our results, we consider that the cone foraging behavior of white-headed woodpeckers may be less important than suggested in some past studies. Multiple papers on nesting ecology have described this species as dependent or reliant on pine seeds without direct observations of foraging within their populations (e.g., Hollenbeck et al, 2011;Wightman et al, 2010). Our results add to a larger body of literature that indicates that cone foraging is likely opportunistic.…”

“…While their nesting ecology has been well-studied range-wide (Hollenbeck et al, 2011;Milne and Hejl, 1989;Raphael and White, 1984;Wightman et al, 2010), studies of white-headed woodpecker foraging have mostly focused on southern populations (Hanson and North, 2008;Raphael and White, 1984). Four foraging studies have been conducted in the northwestern states of Oregon, Washington, and Idaho.…”

Cameras Show Sciurids Visiting White-Headed Woodpecker Nests Without Depredating Contents

“…Anecdotal evidence suggests that they are nest predators for white-headed woodpeckers as well (Wightman et al 2010). We were therefore surprised to observe 23 visits by sciurids to successful white-headed woodpecker nests from the incubation to late nestling stages in which predation did not occur.…”

“…We also encourage research to test prevailing hypotheses about how woodpecker nests are protected. For white-headed woodpecker, researchers have hypothesized that nests may be protected from sciurid depredation by 1) being placed in areas of low sciurid abundance (which leads to low encounter rates by sciurids; Wightman et al 2010;Hollenbeck et al 2011; see also review by Paclik et al 2009), 2) being placed in areas where sciurids have a difficult time locating nest sites (such as areas of high tree density, which also leads to low encounter rates by sciurids; Hollenbeck et al 2011), and 3) parental attentiveness/defense (Hollenbeck et al 2011;Kozma and Kroll 2012). Nests did not seem protected by low encounter rates in our study.…”

“…The white-headed woodpecker occurs in dry pine forests in western North America and is thought to face nest predation mostly from diurnal rodents in the family Sciuridae (hereafter, sciurids), including golden mantled ground squirrel Callospermophilus spp., pine squirrel Tamiasciurus spp., and chipmunks Tamias spp. (Wightman et al 2010;Hollenbeck et al 2011;Kozma and Kroll 2012). Past studies have reported nest success as low as 39% (Hollenbeck et al 2011), and nest predation is considered one of the primary factors limiting populations .…”