Bicknell's Thrush
Catharus bicknelli
Bicknell's thrush is just slightly smaller than the other northern migratory Catharus thrushes, with an average length of approximately 17 cm (6.7 in) and a weight ranging generally from 26 to 30g. Both sexes are identical in the field and are roughly the same size, although males average slightly larger in wing length. Adults are olive-brown to brownish on the upperparts (head, nape, back) contrasting with chestnut-tinged tail. The contrast is, however, less evident in worn plumage. Voice: Vocalizing mostly at dawn and dusk, the song is mostly performed by the male, but sometimes also by females. Like all North American thrushes, Bicknell's thrush song is flute-like. High pitched and vibrant, the song is composed of four phrases: "chook-chook, wee-o, wee-o, wee-o-ti-t-ter-ee". Unlike in the gray-cheeked thrush, the pitch of the last phrase is constant or rising.
ID text from Wikipedia, CC BY-SA 4.0

Black-headed Nightingale-Thrush
Catharus mexicanus
The black-headed nightingale-thrush is 15 to 16.5 cm (5.9 to 6.5 in) long and weighs about 30 g (1.1 oz). Adult males of the nominate subspecies C. m. mexicanus have a black crown and a dark gray face with a bright orange eye-ring. Their upperparts are olive-brown. Their throat is white with faint dark streaks, their breast and flanks pale grayish brown, and their belly and vent white. Adult females are similar to males but have a browner head and breast. Subspecies C. m. cantator is slightly smaller than the nominate with a much grayer face and throat and an olive wash on the breast. C. m. Voice: The black-headed nightingale-thrush sings mostly at dawn, dusk, and in the afternoon. Its song is "a series of rapid, thin, flute-like but slightly tinny, fuzzy phrases...e.g. dleet-dloo-dlee-dlee". Its calls include a "harsh complaining upslurred mew, rreahr, meahh or dzeeeet", a "hard dry rattle or trill when agitated", a "soft blurred pseeer", a "slow plaintive chowrr", "grrr", and "meww".
ID text from Wikipedia, CC BY-SA 4.0
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Bicknell's Thrush and Black-headed Nightingale-Thrush.