Black-billed Thrush

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. debilis has more white on the throat and upper breast than the nominate, with weaker streaks on the throat and grayer breast and flanks.

The black-billed thrush has a disjunct distribution. The nominate subspecies is found in Colombia's Central and Eastern Andes. Subspecies T. i. goodfellowi is found in Colombia's Cauca River valley and on the western slope of the country's Western Andes. The range of T. i. debilis is separate from those of the other two subspecies and is much larger. It extends on both slopes of the Venezuelan Andes from Barinas and Zulia states southwest across eastern Colombia and south through eastern Ecuador and eastern Peru into northern Bolivia, and from those countries into most of western and central Amazonian Brazil, there mostly along major river corridors. The black-billed thrush inhabits a wide variety of semi-open to open landscapes. These include the edges and clearings of humid forest, gallery forest in open savanna, somewhat open secondary forest, shade coffee plantations, early succession areas, brushy pastures, and human-maintained areas like parks and gardens. In elevation it ranges up to 1,600 m (5,200 ft) in Venezuela, to 2,600 m (8,500 ft) in Colombia, to 1,200 m (3,900 ft) in Ecuador and Peru, and to 2,000 m (6,600 ft) in Brazil.

The black-billed thrush feeds on berries, seeds, insects, and other invertebrates like worms. It usually forages singly or in pairs and seldom joins mixed-species feeding flocks. It takes fruit mostly in trees and shrubs but also feeds on the ground in sheltered areas.