Habitat Association Patterns of Breeding Birds and Small Mammals in Douglas-Fir/Hardwood Stands in Northwestern California and Southwestern Oregon

We surveyed birds and small mammals in 45 forest stands from southern Oregon, near Cave Junction, south into northern California, near Branscomb. Over this 350-km distance, we found 71 species of birds and 7 species of mammals that were common enough for detailed analysis. Fourteen species of birds and two mammals reached peak abundances in older (mature and old-growth) forests; however, none appeared limited to these forests. The species were: Allen's hummingbird, hairy woodpecker, pileated woodpecker, Hammond's flycatcher, western flycatcher, gray jay, chestnut-backed chickadee, red-breasted nuthatch, brown creeper, winter wren, golden-crowned kinglet, wrentit, hermit warbler, blackheaded grosbeak, Douglas' squirrel, and the California red-backed vole. In addition, about half of the species were correlated with total conifer or hardwood stems. The abundance of many species also differed among the three geographic regions we sampled. These differences could also be associated with elevation because our northern stands tended to be at higher elevations than were the southern stands. Our community analysis of the birds showed separations between different regions, and between the avian communities of young forests and those of older (mature and old-growth) forests. The mature and old-growth bird communities were not readily separable from each other.