부산대학교 도서관

Parental roles in nestling provisioning and composition of prey brought to nestlings are not well-studied for North American woodpeckers (Picidae). We studied nestling diets and the role of adult Hairy (Picoides villosus) and White-headed woodpeckers (Picoides albolarvatus) in provisioning nestlings and nest sanitation during 2009-2011 in managed ponderosa pine (Pinus ponderosa) forests, Cascade Range, Washington, USA. Male White-headed Woodpeckers removed fecal material from cavities more frequently than females; a difference we did not observe between sexes in Hairy Woodpeckers. Male and female White-headed Woodpeckers, and female Hairy Woodpeckers, fed significantly more small (beak closed when holding prey) than large prey (beak unable to close when holding prey) to nestlings. We did not find differences in provisioning rates by sex of the parent, by nestling age, or by date of provisioning trip for either species. Morisita's Index (C) of diet overlap showed a large similarity in the nestling diets of Hairy and White-headed woodpeckers (C = 0.81), and dietary niche breadth was low for both species. Of the prey we identified, larvae of wood-boring beetles (Coleoptera: Cerambycidae and Buprestidae) were most frequently fed to nestlings by both species. White-headed Woodpeckers fed caterpillars (Lepidoptera) and winged prey to nestlings more often than Hairy Woodpeckers. The diet of Hairy Woodpecker nestlings did not change appreciably over the nesting season, with wood-boring beetle larvae having the highest relative frequency for most of the breeding period. In contrast, relative frequency of wood-boring beetle larvae in the diet of White-headed Woodpecker nestlings declined toward the end of the breeding period as the relative frequency of caterpillars increased. Our results suggest that both sexes of these woodpeckers contribute equally to nestling provisioning. [ABSTRACT FROM AUTHOR]