Nest-Site Habitat Use by White-Headed Woodpeckers in the Eastern Cascade Mountains, Washington

The white-headed woodpecker (Picoides albolarvatus) is strongly associated with old-growth ponderosa pine (Pinus ponderosa) forest, a degraded and increasingly uncommon habitat in the Pacific Northwest. We investigated the nest-site habitat use of this species by collecting vegetation data at 21 known nest sites in the eastern Cascades of Washington, 12 of which we found in 1999. Sixteen of 17 (94%) nests in the ponderosa pine vegetation zone were in the 72% of the zone that occurred below 1219 m, and 15 (88%) nests were on slopes of <20% (which comprised 48% of the zone); the total area characterized by both slopes <20% and elevation below 1219 m was 181,664 ha or 33.6% of the vegetation zone. Most (16 of 21) nests were in ponderosa pines and 81% (17 of 21) were in snags. The nest snags and trees were generally large, with a mean diameter at breast height of 51.5 cm ( = 5.13). The mean height of nest snags and trees was 12.6 m ( = 2.33), and the mean height of the nest cavity entrance was 5.8 m ( = 1.37). Compared to random sites located <1 km from each nest, nest sites were characterized by a greater abundance, size, and basal area of large trees and snags, primarily ponderosa pines. Management of habitat for this species should include retention of 6 to 8 large snags/0.8 ha and 8 to 10 large trees/0.8 ha in the immediate vicinity of nesting areas. Habitat requirements at the home range scale should be investigated.