Evaluating rates of nestling provisioning by adult birds provides insight into foraging strategies and reproductive effort. In most biparental avian species, both males and females provision the young, although this task is not always shared equally between sexes. In woodpeckers (Picidae), biparental care is thought to be necessary to successfully raise offspring, resulting in social monogamy for most woodpecker species. Unlike other avian groups, such as passerines, where females generally invest more than males in raising offspring, male woodpeckers contribute significantly to raising you
The White-headed Woodpecker (Picoides 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 Washington, the White-headed Woodpecker (Picoides albolarvatus) is listed as a species of concern because of its association with old-growth ponderosa pine (Pinus ponderosa) forests. In 2011, we began a color-marking study of White-headed Woodpeckers in managed stands dominated by ponderosa pine. We captured adult birds with mist nets, hoop nets, and noose traps at nest cavities and water features. We did this by using call playbacks in conjunction with a taxidermy mounted female White-headed Woodpecker.
Interior ponderosa pine (Pinus ponderosa) forests of the Pacific Northwest have changed dramatically since the time of European settlement. As a result of decades of fire suppression and timber management that focused on selective removal of large-diameter trees, ponderosa pine forests today have high densities of small diameter trees and low densities of large diameter trees and snags, as well as an encroachment of shade tolerant tree species.
The White-headed Woodpecker (Picoides albolarvatus) is a primary excavator that occurs in pine- (Pinus spp.) dominated habitats throughout its geographic distribution. Throughout the interior Pacific Northwest, the White-headed Woodpecker is historically associated with large-diameter ponderosa pine (Pinus ponderosa) forests. Historically these pine forests were maintained by frequent fires that occurred every 5–15 years. Old trees (>150 years) in these historic forests were 40–91 cm dbh and ranged in density from 19 to 49 per hectare.
Woodpeckers are considered keystone species because of their broad effects on other species. In nesting and foraging, woodpeckers create cavities and excavations that other species use, they aid in controlling forest insects, and they may help in dispersing spores of fungi that are agents of decay. Despite the importance of woodpeckers to forested ecosystems, few studies have examined metrics of woodpecker demography such as reproductive success or nest survival or have investigated the associations of habitat characteristics with these or related metrics.