Arthropod Food of Some Forest-Inhabiting Birds

The diets of 25 species of forest-inhabiting birds were examined in California from 1962 to 1968. Coleoptera and Hymenoptera comprised the bulk of the diets. Coleopterans were, in decreasing amounts, the most common food of the three-toed woodpecker, Steller's jay, American robin, brown creeper, hairy woodpecker (both sexes), dark-eyed junco, downy woodpecker (both sexes), olive-sided flycatcher, western wood-pewee, and white-headed woodpecker (both sexes). Hymenopterans, mainly ants, were the most common food of the northern flicker, Williamson's sapsucker, red-breasted sapsucker, and acorn woodpecker. White-headed woodpecker (both sexes) also ate ponderosa-pine seeds in the fall. Hairy woodpecker (both sexes) fed on the seeds of ponderosa pine and sugar pine. Detailed estimates of foods consumed by item and volume from analyses of stomach contents of 241 specimens are presented.