A cryptic new species of hummingbird of the Campylopterus largipennis complex (Aves: Trochilidae).

A new species of Campylopterus sabrewing is described from eastern Brazilian tropical dry forests occurring below 900 m asl. Its holotype (MZUSP 99024) is an adult female from Sítio Duboca (16°43'19''S, 43°58'20''W, elevation 840 m), municipality of Montes Claros, state of Minas Gerais. A taxonomic revision based on more than 1,000 museum specimens revealed that the new taxon, together with C. largipennis, C. diamantinensis and C. obscurus (with C. aequatorialis considered as a subjective junior synonym) should be ranked as species. We provide a key to permit easy identification of the four species. The new species is very similar to the parapatric C. diamantinensis of high altitude "campos rupestres" above 1,000 m asl, differing from it by its smaller size and longer light tail tips, as well as by sternum measurements. Given the several threats faced by the habitat to which the new species is endemic, we propose to consider it as Vulnerable under the IUCN criteria.

Melanopareia bitorquata (d'Orbigny & Lafresnaye, 1837) is a distinct species: an appraisal of morphological variation in the Collared Crescentchest Melanopareia torquata (zu Wied-Neuwied, 1831) (Aves: Melanopareiidae).

The Collared Crescentchest Melanopareia torquata is a poorly known and inconspicuous species of open savannas and grasslands in central Brazil, Paraguay and Bolivia. Three subspecies are currently recognized, but their taxonomic limits, ranges and conservation status are far from well-established. This paper analyses individual and geographic variation in this species on the basis of body measurements and plumage coloration of 119 specimens. A clinal pattern of body size variation and considerable mensural overlap precludes a clear-cut separation between the two subspecies restricted to Brazil, and there is evidently sexual dichromatism in some Brazilian populations. However, M. t. bitorquata shows highly distinct plumage features in parapatry with other forms, strongly suggesting it should be treated as a full species.

Morphological data support the recognition of four species in the genus Sirystes Cabanis & Heine, 1859 (Aves: Tyrannidae).

Sirystes is a widespread genus in the Neotropical region. Historically, five subspecies were recognized in a single widespread species, but more recently four separate species have been recognized, based on vocalizations and limited morphological data. In this paper, we analyze individual and geographic variation in this genus on the basis of body measurements and plumage coloration of 514 specimens, including all name-bearing types available. We conclude that the four recently proposed species, S. sibilator, S. albogriseus, S. albocinereus, and S. subcanescens, can also be diagnosed by morphological data, corroborating more recent taxonomic treatments. We identified possible hybrids between S. sibilator and S. albocinereus from a narrow zone of contact in central Bolivia. We show that Sirystes sibilator atimastus Oberholser, 1902 represents a point on a cline within S. sibilator (Vieillot, 1818), and it is here regarded as a subjective junior synonym of the latter. We also provide new observations on the range and diagnosis of S. subcanescens, a name that has been frequently misused, and present a redescription of the four recognized species, as well as reviewing their range and natural history.

A Paleogene origin for crown passerines and the diversification of the Oscines in the New World.

In this study, we present a detailed family-level phylogenetic hypothesis for the largest avian order (Aves: Passeriformes) and an unmatched multi-calibrated, relaxed clock inference for the diversification of crown passerines. Extended taxon sampling allowed the recovery of many challenging clades and elucidated their position in the tree. Acanthisittia appear to have diverged from all other passerines at the early Paleogene, which is considerably later than previously suggested. Thus, Passeriformes may be younger and represent an even more intense adaptive radiation compared to the remaining avian orders. Based on our divergence time estimates, a novel hypothesis for the diversification of modern Suboscines is proposed. According to this hypothesis, the first split between New and Old World lineages would be related to the severing of the Africa-South America biotic connection during the mid-late Eocene, implying an African origin for modern Eurylaimides. The monophyletic status of groups not recovered by any subsequent study since their circumscription, viz. Sylvioidea including Paridae, Remizidae, Hyliotidae, and Stenostiridae; and Muscicapoidea including the waxwing assemblage (Bombycilloidea) were notable topological findings. We also propose possible ecological interactions that may have shaped the distinct Oscine distribution patterns in the New World. The insectivorous endemic Oscines of the Americas, Vireonidae (Corvoidea), Mimidae, and Troglodytidae (Muscicapoidea), probably interfered with autochthonous Suboscines through direct competition. Thus, the Early Miocene arrival of these lineages before any other Oscines may have occupied the few available niches left by Tyrannides, constraining the diversification of insectivorous Oscines that arrived in the Americas later. The predominantly frugivorous-nectarivorous members of Passeroidea, which account for most of the diversity of New World-endemic Oscines, may not have been subjected to competition with Tyrannides. In fact, the vast availability of frugivory niches combined with weak competition with the autochthonous passerine fauna may have been crucial for passeroids to thrive in the New World.

Morphological variation in the Cinnamon Tanager Schistochlamys ruficapillus Aves: Thraupidae).

The Cinnamon Tanager Schistochlamys ruficapillus inhabits semi-open grassy country, primarily in Brazil south of Amazonia. Three subspecies are currently recognized, one of which, S. r. sicki, is poorly known and endemic to the central Brazilian savannas (Cerrado). This paper analyses individual and geographic variation in this species on the basis of body measurements and plumage coloration. Larger birds are usually found farther south and at higher elevations, while smaller birds are found farther north and at lower elevations, as predicted by Bergmann's rule. Nevertheless, some unexpectedly small individuals (referable to S. r. sicki) can be found in central Brazil. Individual and geographical variation in plumage coloration is substantial, but it is not closely tied to variation in body size. Therefore, given the large number of specimens intermediate between the three subspecies, we propose to consider the Cinnamon Tanager a monotypic but highly variable species. The recognition of three subspecies by previous taxonomists was due to small sample sizes associated with large gaps in sampling. 

Taxonomy, distribution, natural history and conservation of the Russet-mantled Foliage-gleaner Syndactyla dimidiata (Pelzeln, 1859) (Aves: Furnariidae).

Russet-mantled Foliage-gleaner is an extremely poorly known species, the range of which is centered in the Brazilian Cerrado, where it inhabits riparian forests. Two subspecies are recognized, but the limits of their ranges are controversial. Furthermore, it was recently suggested that the species is one of the few in the family Furnariidae to show sexual dichromatism. In this paper we examined the plumage coloration and morphometrics of 33 study skins (85% of the available specimens). We conclude that the geographic variation and sexual dichromatism reported for S. dimidiata originated from misinterpretation of the plumage variation observed in this species, which is best considered monotypic. We also present natural history data on Russet-mantled Foliage-gleaners and suggest considering it a globally Vulnerable species.