Bicknell's Thrush vs Black-billed Nightingale-Thrush

Bicknell's Thrush

Catharus bicknelli

Small28 gForest

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

Recorded by Killian Sullivan · Wilmington, Essex County, New York, United States · CC0

Photo: Ryan F. Mandelbaum · CC BY 4.0

Black-billed Nightingale-Thrush

Catharus gracilirostris

Small21 gForest

The black-billed nightingale-thrush is about 15 cm (5.9 in) long and weighs about 20 g (0.71 oz) The sexes have the same plumage. Adults of the nominate subspecies have a slate-gray forecrown, an olive-brown crown, and a slate-gray face. Their upperparts, wings, and the upper side of their tail are olive-brown. Their throat is whitish, the middle of their lower belly light gray to whitish, and the rest of their underparts slate-gray with an olivaceous band across the breast. They have a dark brown iris, a black bill, and dark gray legs and feet. Voice: The black-billed nightingale-thrush has a variety of vocalizations. Its song is composed of up to about 18 phrases, each different than the preceding one, and typically alternating between higher and lower pitches. Males usually sing from within understory vegetation and only seldom much higher. During the breeding season males countersing.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Anthony Mora Aguilar · CC BY 4.0

Photos and recordings are credited to their authors under the licence shown. Full profiles: Bicknell's Thrush and Black-billed Nightingale-Thrush.