The Mountain Thrush (Turdus plebejus) is a large thrush which breeds in highlands from southern Mexico to western Panama. It was formerly known as the Mountain Robin.
This is a bird of tall mountain forests and adjacent more open areas and woodland edge. Its prefererence is for oak with many epiphytes and mosses, normally from 1800 m altitude to the timberline. It descends in flocks as low as 900 m in the wet season.
It builds a grass or rootlet-lined large cup nest, concealed amongst epiphytes, 3"?12 m above the ground on a tree branch. The female lays 2"?3 unmarked greenish-blue eggs between March and June.
The Mountain Thrush resembles other Turdus thrushes in general appearance and habits. It is 23-26 cm long, and weighs 86 g on average. The adult is uniformly dull olive-brown with faint white streaks on the throat. The bill is black and the legs are dark brown. The juvenile resembles the adult, but has but has buff or orange streaks on the head and upperparts, and dark spotting on the underparts.
There are three poorly-defined subspecies:
- Nominate T. p. plebejus of the mountains of Costa Rica and western Panama is described above.
- T. p. differens from the Pacific slope of Mexico to Caribbean Guatemala is more olive above, and more olive brown and less grey below
- T. p. rafaelensi of the highlands from Honduras to northwestern Nicaragua is intermediate between the northern and southern subspecies above, and is often merged with differens.
Two superficially similar relatives share this species range. Sooty Thrush is blacker with an orange bill, eyering and legs, and Clay-colored Thrush is much paler and yellow-billed.
The Mountain Thrush behaves like other thrushes. It forages on large branches or on the ground, in flocks when not breeding, progressing in hops and dashes with frequent stops. It turns leaf litter seeking small fruits, insects and spiders.
The breeding season song is an unthrushlike mechanical monotone chip chip cher chip chip cher cher, and the call is a high seee or whip.