Interior ponderosa pine (Pinus ponderosa) forests of the Pacific Northwest have changed considerably since the time of European settlement. As a result of effective 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 trees. These conditions can promote outbreaks of disease and insect pests which, in addition to high tree density, make these forests susceptible to stand replacement fires. In response, some land management agencies and private industrial landowners use forest management practices to reduce fire intensity and aid in restoring these forests to a condition that is open, park-like, and dominated by large-diameter trees. However, it will take many years and multiple management actions to reach this goal. Therefore, it is important to understand how cavity-nesting birds use current forest conditions, particularly in regard to nest-site characteristics, because land managers can manipulate these habitat features.
In 2003, we began a study of the reproductive biology of cavity-nesting birds in managed ponderosa pine forests of the eastern Cascade Range. Our focal species is the White-headed Woodpecker (Dryobates albolarvatus). In Washington, the White-headed Woodpecker is listed as a species of concern because of its association with old-growth ponderosa pine forests. Although the White-headed Woodpecker has recently been documented inhabiting early- to mid-seral managed forests, information is limited regarding its reproductive success in these forests. We also included the Hairy Woodpecker (D. villosus), Northern Flicker (Colaptes auratus), and Western Bluebird (Sialia mexicana) in our reproductive ecology study because information regarding the nest-site characteristics and reproductive success of these species in managed ponderosa pine forests has not been investigated. Ultimately, we hope to determine if managed ponderosa pine forests function as a population source or sink for the White-headed Woodpecker.
This project is currently ongoing with some aspects of the research having already been completed. More information regarding ongoing and completed research and its results, along with peer-reviewed publications, can be accessed by clicking the links below.
In 2014-2015, we conducted a study investigating the reproductive biology of the Gray Flycatcher (Empidonax wrightii) in managed ponderosa pine stands along the eastern Cascade Range. The Gray Flycatcher is a Neotropical migrant that breeds throughout the Great Basin in habitats dominated by sagebrush (Artemisia spp.), bitterbrush (Purshia tridentata), pinyon pine (Pinus edulis), juniper, and ponderosa pine. This species is near the northern limit of its geographic range in Washington and was first reported here in 1970, with the first Washington breeding record documented in 1972. Both of these historic sightings were within the ponderosa pine habitat zone. Despite the species now being found as a breeder throughout much of the low elevation ponderosa pine forest in eastern Washington, little is known about the breeding ecology of this species in this habitat. To address this lack of information, our study investigated habitat characteristics associated with Gray Flycatcher nest sites and evaluate how these habitat characteristics influence nest survival in managed ponderosa pine stands.
Lastly, you will find other research articles focusing on White-headed Woodpecker ecology we have co-authored with other colleagues under the link for "collaboration research articles"