Pacific Northwest Research Station - Ecological Process & Function - Wildlife Ecology Team

Pileated Woodpecker Research Projects

Ecology and management of pileated woodpeckers in coastal forests of Washington.

Ecology and management of pileated woodpeckers in coastal forests of Washington We have proposed that the pileated woodpecker may be a keystone habitat modifier in the Pacific Northwest because it provides habitat for a wide array of species, including several that are of management concern within the range of the northern spotted owl (e.g., bufflehead, common merganser, flammulated owl, Vaux’s swift, fisher, marten, northern flying squirrel, and silver-haired bat). Additionally, pileated woodpeckers provide foraging opportunities for other species, accelerate decay processes and nutrient cycling, and may facilitate inoculation of heart-rot fungi and mediate insect outbreaks. Prior to the implementation of the Northwest Forest Plan (NWFP) in 1994, the pileated woodpecker was designated as a management indicator species (MIS) for mature and old-growth forest conditions on 16 of 19 National Forests in Region 6 due to its dependence on large snags and logs for nesting, roosting, and foraging. With the implementation of the NWFP, however, most National Forests no longer maintained habitat areas for pileated woodpeckers because it was believed that prescriptions for preserving or for promoting the development of late-successional forest conditions in the NWFP would also maintain viable populations of pileated woodpeckers. However, the efficacy of standards and guidelines in the NWFP for providing adequate nesting, roosting, or foraging habitat for pileated woodpeckers was never evaluated critically, as there was no empirical basis for such assessments within the range of the northern spotted owl. Prior to this study, information on the ecological relations of pileated woodpeckers in the Pacific Northwest were derived largely from studies conducted in northeastern Oregon, and no study had investigated habitat selection by pileated woodpeckers at the landscape scale in the Pacific Northwest.

Our objectives are to (1) describe characteristics of nest and roost trees selected by pileated woodpeckers in coastal forests, (2) identify physiographic and vegetative site characteristics that are selected by pileated woodpeckers for nesting and roosting, (3) investigate home range size and habitat selection at the landscape scale, and (4) describe foraging strategies and diet of pileated woodpeckers within a managed west-side landscape. Accordingly, we identified all potential breeding pairs of pileated woodpeckers within a 9,350 ha study area, conducted ground searches to locate active nests, and trapped adults at nests to attach radio-transmitters. We radio-tracked adult birds year-round to locate roost trees, document habitat use, and determine home range size. To test hypotheses regarding habitat selection, we sampled trees available to pileated woodpeckers for nesting and roosting throughout the 9,350 ha study area. To investigate habitat use and home range composition at the landscape scale, satellite imagery of the study area was classified into vegetation types based on forest composition, tree size, and canopy closure.

Team lead: Keith B. Aubry and Catherine M. Raley

Cooperators: Olympic National Forest

USDA Forest Service - Pacific Northwest Research Station - Olympia Forestry Sciences Laboratory
Last Modified: Monday, 31 January 2011 at 16:52:22 EST