Speciation in savanna birds in South America: The case of the Least Nighthawk Chordeiles pusillus (Aves: Caprimulgidae) in and out of the Amazon.

The Least Nighthawk Chordeiles pusillus is widespread wherever there are savannas in the South American tropics, often in isolated patches, such as white-sands savannas in the Amazon rainforest realm. Here, we investigate genetic relationships between populations of the Least Nighthawk to understand historical processes leading to its diversification and to determine dispersal routes between northern and southern savannas by way of three hypothesized dispersal corridors by comparing samples from white-sand savannas to samples from other savannas outside of the Amazon rainforest region. We use 32 mtDNA samples from the range of C. pusillus to infer a dated phylogeny. In a subset of 17 samples, we use shotgun sequences to infer a distance-based phylogeny and to estimate individual admixture proportions. We calculate gene flow and shared alleles between white-sand and non-Amazonian populations using the ABBA-BABA test (D statistics), and Principal Component Analysis (PCA) to examine genetic structure within and between lineages. Finally, we use species distribution modelling (SDM) of conditions during the Last Glacial Maximum (LGM), currently, and in the future (2050-2080) to predict potential species occurrence under a climate change scenario. Two main clades (estimated to have diverged around 1.07 million years ago) were recovered with mtDNA sequences and Single Nucleotide Polymorphism (SNPs) and were supported by NGSadmix and PCA: one in the Amazon basin white-sand savannas, the other in the non-Amazonian savannas. Possible allele sharing between these clades was indicated by the D-statistics between northern non-Amazonian populations and the white-sand savanna population, but this was not corroborated by the admixture analyses. Dispersal among northern non-Amazonian populations may have occurred in a dry corridor between the Guianan and the Brazilian Shield, which has since moved eastward. Our data suggest that the lineages separated well before the Last Glacial Maximum, consequently dispersal could have happened at any earlier time during similar climatic conditions. Subsequently, non-Amazonian lineages became more divergent among themselves, possibly connecting and dispersing across the mouth of the Amazon River across Marajó island during favourable climatic conditions in the Pleistocene.

AVONET: morphological, ecological and geographical data for all birds.

Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when species-level information is complete. Here we present the AVONET dataset containing comprehensive functional trait data for all birds, including six ecological variables, 11 continuous morphological traits, and information on range size and location. Raw morphological measurements are presented from 90,020 individuals of 11,009 extant bird species sampled from 181 countries. These data are also summarised as species averages in three taxonomic formats, allowing integration with a global phylogeny, geographical range maps, IUCN Red List data and the eBird citizen science database. The AVONET dataset provides the most detailed picture of continuous trait variation for any major radiation of organisms, offering a global template for testing hypotheses and exploring the evolutionary origins, structure and functioning of biodiversity.

A Survey for Escherichia coli Virulence Factors in Asymptomatic Free-Ranging Parrots.

Parrots in captivity are frequently affected by Escherichia coli (E. coli) infections. The objective of this study was to collect information on the carrier state for E. coli pathotypes in asymptomatic free-ranging parrots. Cloacal swabs were collected from nestlings of Hyacinth, Lear's macaws and Blue-fronted Amazon parrots and tested by polymerase chain reaction (PCR) for virulence factors commonly found in enteropathogenic, avian pathogenic, and uropathogenic E. coli strains. In total, 44 samples were cultured and E. coli isolates were yielded, from which DNA was extracted and processed by PCR. Genes commonly found in APEC isolates from Blue-fronted Amazon parrots and Hyacinth macaws were expressed in 14 of these 44 samples. One atypical EPEC isolate was obtained from a sample from Lear's macaw. The most commonly found gene was the increased serum survival (iss) gene. This is the first report, that describes such pathotypes in asymptomatic free-living parrots. The findings of this study suggest the presence of a stable host/parasite relationship at the time of the sampling brings a new understanding to the role that E. coli plays in captive and wild parrots. Such information can be used to improve husbandry protocols as well as help conservation efforts of free-living populations.