Abstract Kinglet Calyptura Calyptura cristata is one of the great enigmas of the South American avifauna. Endemic to an apparently tiny area of south-eastern Brazil, in the Atlantic Forest biome, the species was not definitely seen between sometime in the second third of the 1800s and 1996, when it was briefly rediscovered in submontane forest north-west of Rio de Janeiro. Since then, C. cristata has been reported several times, but without documentation and always by single observers. It is currently considered Critically Endangered by BirdLife International, and various authors have speculated that the species might already be extinct. Given the extreme paucity of knowledge of this species, we provide a complete inventory of museum material for Kinglet Calyptura - more than 100 specimens are listed, the majority held in European collections, almost doubling previous estimates made in the literature. Several are held in relatively small institutions, thereby suggesting that yet more specimens might still be identified or found. In addition, with the benefit of this large sample of material, we discuss morphological variation in the species and we hypothesise particularly about the appearance of male, female and juvenile plumages.

Abstract Culicivora caudacuta occurs in the Cerrado, Pampa and Chaco grasslands of Bolivia, Brazil, Paraguay, Argentina and Uruguay. Its breeding biology is poorly known. Here, I present a summary of the published information and new data gathered between 2003 and 2009 in southeast Brazil at Tapira, Minas Gerais. Breeding occurred during the rainy season (October to March), clutch size being three eggs. Juveniles and immatures show a different plumage from the adults, mostly brownish orange. All nests studied at Tapira showed evidence of cooperative breeding, with one helper engaged in incubation and provisioning the young. This is the first observations of this behavior for the species. The species has a wider range than currently understood and its presence in protected areas is similarly more common.