Bird populations and vegetation characteristics in managed and old-growth forests, northeastern Oregon.

The abundance of large snags in old-growth forests was probably responsible, in part, for the relatively high numbers of red-breasted nuthatches Sitta canadensis and most other hole-nesting birds observed in this habitat. Large trees were indirectly important to hole-nesting birds because they provided a source of large snags. Grand fir Abies grandis trees were used by Townsend's warblers Dendroica townsendi and golden-crowned kinglets Regulus satrapa when foraging and nesting. The abundance of these 2 bird species in old-growth forests is attributed to the presence of this understory tree component. Species of birds that were more abundant in managed forests than in old-growth forests appeared to be attracted to the open structure of the managed stands. The effects are discussed of replacing old-growth forests with managed forests in bird species in NE Oregon.-from Authors