Foraging methods and habitats used by downy, hairy, pileated, red-bellied, and red-headed woodpeckers, and common flickers were studied in southwestern Virginia during the breeding season, post-breeding season, and winter. The food resource used by the six species was partitioned by species' use of different macro-habitats (forest structure), micro-habitats (positions within trees), and foraging methods. Differences in foraging behaviors of male and female downy and hairy woodpeckers were also detected. Seasonal changes in foraging methods of woodpeckers were observed. Downy, hairy, and pileated woodpeckers used subcambial foraging methods to a greater extent in the winter than in the breeding and post-breeding seasons. This was probably a response to the location of prey items at different seasons. Food items were apparently more superficially available during the breeding and post-breeding season than in the winter. Red-headed woodpeckers responded to the winter food shortage by feeding on acorns collected and stored in the previous season. Many of the common flickers avoided winter shortages by migrating out of the area as the population density of flickers was greatly reduced in the winter from the levels present in the breeding and post-breeding seasons. It is suggested that bill and body size of downy, hairy, and pileated woodpeckers may be related more to the depth to which each species penetrates trees when foraging rather than to prey or food size as has been suggested in other species. Downy, hairy, and pileated woodpeckers showed varied responses to changing resource availability in their breadths of foraging methods and micro-habitat used. Predicted changes in breadth indicate that breadth should increase as the food resource becomes less dense, and decrease as the resource becomes more dense, Downy woodpeckers were the only species to fit the predicted response pattern for all aspects of foraging behavior examined. Pileated woodpeckers decreased in breadth of foraging methods and micro-habitats used during the winter. Net overlap between downy and hairy, and downy and pileated woodpeckers decreased in the winter from what it had been during the post-breeding season. Overlap between hairy and pileated woodpeckers, however, increased in all three aspects of foraging behavior examined suggesting the possibility that some unused "ecological space" existed between these two species allowing their foraging behaviors to become more similar in the winter. It is suggested that changes in overlap were the result of competition in the past. Pressures causing differences in foraging methods between sexes may be greater than those between species for the groups examined. Overlap of foraging methods in species pair comparisons of the downy, hairy, and pileated woodpeckers was greater than that between sexes of downy and hairy woodpeckers. / Ph. D.