Melanopareiidae – Crescent-chests

The Melanopareiidae family, or Crescentchests in the vernacular, are a family of birds from South America. The genus has long been placed with the tapaculos in the Rhinocryptidae family. Their placement there has been questioned and in 2007 the genus was placed in its own family, Melanopareiidae by the South American Classification Committee, it has since been split from the Tapaculos by DNA sequencing (2009).

They range in length from 14 to 16 cm and in weight from 16 to 23 g. They have relatively long tails compared to the tapaculos. The plumage is striking with a distinctive band across the chest that gives the group their name.

They are birds of arid scrub and generally forage on the ground, but their diet has not yet been recorded. Two species, the Collared Crescentchest and Olive-crowned Crescentchest, are widely distributed across central and southern Brazil, Bolivia, Paraguay and northern Argentina, whilst the other two species have a more restricted distribution in Peru and Ecuador.

Little is known about the behaviour of the crescentchests. The only species about which anything is known about the breeding behaviour is the Olive-crowned Crescentchest. It is a seasonal breeder. Its nest is a 15 cm high cup made of vegetable fibres and palm fronds, hidden in grasses or low shrubs close to the ground. The clutch size is two to three eggs, the eggs are white with blotches or black spots.

No species of crescentchest is considered by the IUCN to be threatened by human activities, but the Marañón Crescentchest is listed as near threatened. Although the species is apparently tolerant of some disturbance it has a tiny global range and is uncommon even within that range.