White-throated Treerunner

The white-throated treerunner is 15 to 16 cm long on average, with a weight between 20 and 27 grams. It has an appearance reminiscent of the nuthatch, with its overall look and plumage, unlike other species in the Furnariidae. Wing chord is from 76 to 86 mm, tail is 52 to 65 mm, and torso from 20 to 23.7 mm. The iris is dark brown. It has a long beak, at around 16 to 23.8 mm with a slight upward curve. Its upper mandible is dark gray and lower mandible a whitish-pale gray. The feet are dark gray, blackish or brown. The species is easily recognized by its white throat, contrasting with its upper parts. Its face is blackish-brown and slightly darker than its head crown, which is a dull brown. The back is a paler chestnut-brown,pulling against the red rump and tail. The wing coverts are dark brown, with red or chestnut brown on the feather edges and tail end. The primaries are darker, the remiges black-brown with light edges and inner primaries marked with a short, light red wing bar. The tail is rounded, with rigid rectrices with shortened barbs ending in small spines up to 9 mm long. A large white zone covers the treerunner's cheek and throat, descending to the middle of the chest. The rest of the lower parts, to the undertail coverts, are made up of white feathers largely bordered with dark brown, giving an irregularly spotted appearance. Both sexes of adults look similar. The chick is distinguished by an ochre-striped crown and back, and often with blackish borders on the throat feathers.