Rufous-chested Tanager

Large dove found in mature montane forests from the western U.S. and Canada into Middle and South America. Soft blue-gray above and unique purplish-gray below, with white crescent on the nape. Yellow feet. Bill is yellow with black tip in northern populations, all yellow in southern ones. Forms large flocks in coniferous forests and montane areas where it feeds on seeds and fruits. When it takes off, wings make loud clapping sound.

Sprightly, small warbler that poses a bevy of identification issues. Dull olive above and yellow below, with a bright eyering and a gray crown bound in by black stripes. Extremely similar to closely-related Martens’s, Gray-crowned, White-spectacled, and Bianchi’s Warblers; often impossible to identify if seen poorly in where range overlap is possible. Weak or absent wingbar distinguishes this species from Whistler’s, Bianchi’s, and White-spectacled warblers. Slightly larger-billed and shorter-tailed and with more restricted white in outer tail feathers than Martens’s and Gray-crowned warblers. Breeding altitudinal range (600–1500 m) can be helpful: does not overlap with higher-breeding Bianchi’s Warbler (1760–3100 m in China) and minutely with Martens’s Warbler (1200–2300 m). Overlap more extensive with Gray-crowned Warbler (120–1830 m in China) and White-spectacled Warbler (1000–1750 m in China). Simple, short song can be an identification clincher: a brief “che-witchy-chew-witchy-chew”, lacking the trilled notes of Martens’s, Gray-crowned, and White-spectacled warbler, and higher in pitch than Bianchi’s Warbler. Forages low, often in dense growth, of temperate evergreen forests, descending during the non-breeding season into forested lowlands, where overlap with non-singing similar species can make identification nearly impossible.

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.