Rusty Tinamou Crypturellus brevirostris is an elusive, ground-dwelling bird of terra firme forest. Although widespread across Amazonian Brazil, the Guiana Shield and extreme south-east Colombia, it is everywhere uncommon. Frequently, only its distinctive voice betrays its presence and therefore most contacts with this tinamou are auditory. Here, we analyse the vocalisations of Rusty Tinamou, a primary and secondary song, which may represent duetting between male and female of a mated pair. We also compare and discuss this vocal behaviour with duetting in other Crypturellus species.

The long-recognised name of the Veery Catharus fuscescens (Stephens 1817) was intended to replace Tawny Thrush Turdus mustelinusWilson, 1812, which was preoccupied by T. mustelinus J. F. Gmelin, 1789. Herein, I demonstrate that T. mustelinus Wilson is unidentifiable because it was based on attributes shared by more than one species, including some features that are a better match to other Catharus species than to Veery. None of the specimens mentioned in Wilson's description is extant. To maintain traditional nomenclature and to prevent destabilising confusion arising from alternative identifications, I designate a neotype for Turdus mustelinus Wilson and its replacement names, including T. fuscescens Stephens, fixing the name to the taxon to which it has been traditionally applied. The neotype is a colour-banded male that was tracked over two consecutive years with light-level geolocator and GPS tracking units. To my knowledge, it is the first bird specimen in any collection for which migratory data were collected with either device.

We complement the only existing nest description for Ruddy Treerunner Margarornis rubiginosus and include observations of nestbuilding and breeding behaviour. We also compare our data with existing information on nest architecture and breeding biology of the closely related Pearled Treerunner M. squamiger and Spotted Barbtail Premnoplex brunnescens. The nest of Ruddy Treerunner was a pendant closed nest below a single tree branch and was mostly constructed of moss. In the nest base there was a circular entrance and a second cavity. The inner chamber was spherical and the egg cup was mostly constructed of roots, fern scales and other plant fibres. Both adults build the nest and care for chicks. We observed a nest helper and removal of faecal sacs by both adults. Many aspects of nest structure and parental behaviour are similar to those of its sister species, thereby supporting existing genetic data.

Interesting sightings in southern Mozambique of 13 species of terns, gulls and skuas are reported, the result of regular observations between October 2010 and September 2017 while I was based in the capital, Maputo. These include the first two records of Black Tern Chlidonias niger, the first fully documented record of Lesser Noddy Anous tenuirostris and the first observations of live Arctic Terns Sterna paradisaea for Mozambique, as well as status updates for Kelp Gull Larusdominicanus, Lesser Black-backed Gull L. fuscus, Sabine's Gull Xema sabini, Gullbilled Tern Gelochelidon nilotica, Swift Tern Thalasseus bergii, Sooty Tern Onychoprionfuscatus, Common Tern Sterna hirundo, Black-naped Tern S. sumatrana, Roseate Tern S. dougallii and Subantarctic Skua Stercorarius antarcticus in southern Mozambique.

In light of speculation in the recent literature concerning the species' intraspecific taxonomy and personal observations, we examined specimens of the Mascarene Swiftlet Aerodramus francicus from both range islands, Mauritius and Reunion, with the aim of documenting any geographical variation in morphology. We found that specimens from Reunion clearly differ from those collected on Mauritius (the type locality) in multiple plumage and biometric characters, and that at least some of these differences are also visible in the field. As a result, we describe the Reunion population as a new subspecies under the Biological Species Concept. Taken together, these insular forms are treated by BirdLife International as Near Threatened, but the declining nominotypical Mauritian population might require a reassessment of its conservation status according to IUCN criteria should future taxonomic research applying an integrative approach indicate that species rank is more appropriate.

Brazilian Merganser Mergus octosetaceus is one of the most endangered bird species in the Americas and one of the rarest ducks in the world. We photographed the species in August 2017, at Serra do Mar State Park, Salesópolis, in eastern São Paulo state. This is the third documented record in São Paulo, but the first for approximately 200 years.

Eight specimens collected in 1878 by the Italian explorer Odoardo Beccari have provided one or more type specimens for two seemingly identical names given to the Sunda Bulbul of Sumatra, now treated as a subspecies of Ixos virescens or perhaps a full species. These names are Hemixus sumatranusWardlaw Ramsay, 1882, and Hemixus sumatranusSalvadori, 1888. The International code of zoological nomenclature is not clearly explicit on the treatment of a name that when introduced was simultaneously a junior homonym and an objective junior synonym. While both names are available, the junior one is invalid because of its homonymy. Because both names are available, both have type material and this is not identical. Here we clarify the situation and the type material applicable.