Different
species of birds use different aspects of vertical structure in
northern forests (hemlock-maple-yellow birch).
A (canopy): warblers (Blackburnian warbler), finches (purple finch), accipters (goshawk), pileated woodpecker, grosbeaks (evening and rose-breasted).
B (understory/shrub): hummingbirds (nests), orioles, insectivores (flycatchers), juncos, brown creeper.
C (ground): ovenbirds,
juncos (feeding), thrushes (robin, Hermit thrush), hummingbirds
(feeding).