The White-headed Woodpecker (Dryobates albolarvatus) is uncommon and non-migratory throughout its geographic range in Washington, where it inhabits forests dominated by ponderosa pine (Pinus ponderosa). In the northern part of their range, White-headed Woodpeckers rely on ponderosa pine seeds as a fall and winter food resource. Although previous research revealed that White-headed Woodpeckers do feed on tree sap in California and Oregon, the characteristics of trees used for sap feeding have not been described in detail. In addition, sap feeding by White-headed Woodpeckers has yet to be described in Washington.
In this study, I describe the characteristics of trees used by White-headed Woodpeckers for sap feeding and comment on observations of sap feeding behavior along the east-slope of the Cascade Range, Yakima County, Washington. Information on the use of tree sap as a food resource by White-headed Woodpeckers will add to our understanding of the natural history of this species, much of which remains unknown.
Determine the characteristics of trees used by White-headed Woodpeckers for sap feeding in managed ponderosa pine forests of the eastern Cascade Range.
This project was conducted in 2008 and is completed. The results from this study were published in the peer-reviewed journal The Northwestern Naturalist in 2010. The .pdf of this paper can be accessed by clicking the link below.