Black-faced Brushfinch

Fairly dull vireo, intermediate between Blue-headed and Plumbeous. Grayish-olive overall, but with yellowish flanks and greenish back. Note white spectacles contrasting with gray head and two whitish wingbars. Breeds in mixed coniferous forests, especially in mountainous areas; winters in Mexico. Often separable from Blue-headed and Plumbeous Vireos by range, but can overlap during migration and winter. Cassin's is less contrasty than Blue-headed, especially between the gray face and whitish throat, and the greenish back blends into the nape and crown. Some birds are best left unidentified.

Average red-bellied trogon of subtropical forests. Male is iridescent green on breast, head, and back; female is brown. Namesake dark mask is usually obvious, especially on females. Nearly identical to Collared Trogon but very little overlap; Masked is almost always found at higher elevations. Where both are possible, look especially at tail pattern on males: large white tips on underside of tail feathers, otherwise dark with very fine white barring. On females, look for evenly barred undertail with large white tips combined with contrasting black face. Usually found singly or in pairs, perched quietly from the understory to the subcanopy. Listen for slow series of 3–6 descending whistles.

Small, oblong-shaped seabird. Breeding plumage mottled brown; darkness varies, but often shows golden tint. Nonbreeding plumage dark gray above and white below, with a white face and large white wing patch. Nests in crevices in rocky scree slopes, particularly around glaciers; forages in coastal glacial outflows. Similar to Marbled and Long-billed Murrelets, but with shorter bill and white outer tail feathers; breeding birds average paler with speckled back, while nonbreeders show white on face extending above the eye.