Black-billed Thrush
Turdus ignobilis
The black-billed thrush is 18.5 to 24 cm (7.3 to 9.4 in) long and weighs 48 to 81 g (1.7 to 2.9 oz). The sexes have the same plumage. Adults of the nominate subspecies T. i. ignobilis have an olive-brown head and upperparts with a slightly darker face and an off-white throat with dark streaks. Their breast and flanks are a paler olive-brown and their belly and undertail coverts are whitish. They have a black iris, a black bill, and dark gray-brown to black legs and feet. Subspecies T. i. goodfellowi has warmer and darker olive-brown upperparts than the nominate. T. i. Voice: The black-billed thrush's song in Venezuela is "a rather slow caroling churre, churre, ee, TE-O-we, churre... and so on with pleasing, relaxed phrases; some individuals sing very repetitive phrases". It calls there are "a loud pfeea! or wEEa!". Similarly, in Peru it is described as "a pleasant and musical caroling, often with a particular phrase given twice".
ID text from Wikipedia, CC BY-SA 4.0
Great Thrush
Turdus fuscater
Adults are 28 to 33 cm (11 to 13 in) in length and weigh 128 to 175 g (4.5 to 6.2 oz), averaging 141 g (5.0 oz), making the species the largest member of the wide-ranging Turdus genus, and one of the largest thrushes although the Amami thrush may match or exceed it in size. It can be easily identified by its yellowish-orange beak and legs and yellow ring around the eye. Slight sexual dimorphism is sometimes present, with males having more strongly coloured legs and eye rings. Tail feathers are long. The plumage is black-brown, darker on wings and tail and pale on the belly.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Black-billed Thrush and Great Thrush.