Limited movement of an avian hybrid zone in relation to regional variation in magnitude of climate change.

Studies of natural hybrid zones can provide documentation of range shifts in response to climate change and identify loci important to reproductive isolation. Using a temporal (36-38 years) comparison of the black-capped (Poecile atricapillus) and Carolina (P. carolinensis) chickadee hybrid zone, we investigated movement of the western portion of the zone (western Missouri) and assessed whether loci and pathways underpinning reproductive isolation were similar to those in the eastern portion of the hybrid zone.

Earth history and the passerine superradiation.

Avian diversification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the diversification of the hyperdiverse perching birds (passerines) is unclear because family level relationships are unresolved and the timing of splitting events among lineages is uncertain. We analyzed DNA data from 4,060 nuclear loci and 137 passerine families using concatenation and coalescent approaches to infer a comprehensive phylogenetic hypothesis that clarifies relationships among all passerine families.

Species delimitation and biogeography of the gnatcatchers and gnatwrens (Aves: Polioptilidae).

The New World avian family Polioptilidae (gnatcatchers and gnatwrens) is distributed from Argentina to Canada and includes 15 species and more than 60 subspecies. No study to date has evaluated phylogenetic relationships within this family and the historical pattern of diversification within the group remains unknown. Moreover, species limits, particularly in widespread taxa that show geographic variation, remain unclear.

A genomic investigation of the putative contact zone between divergent Brown Creeper (Certhia americana) lineages: chromosomal patterns of genetic differentiation.

Sky islands, or montane forest separated by different lowland habitats, are highly fragmented regions that potentially limit gene flow between isolated populations. In the sky islands of the Madrean Archipelago (Arizona, USA), various taxa display different phylogeographic patterns, from unrestricted gene flow among sky islands to complex patterns with multiple distinct lineages. Using genomic-level approaches allows the investigation of differential patterns of gene flow, selection, and genetic differentiation among chromosomes and specific genomic regions between sky island populations.

Molecular systematics of the new world screech-owls (Megascops: Aves, Strigidae): biogeographic and taxonomic implications.

Megascops screech-owls are endemic to the New World and range from southern Canada to the southern cone of South America. The 22 currently recognized Megascops species occupy a wide range of habitats and elevations, from desert to humid montane forest, and from sea level to the Andean tree line. Species and subspecies diagnoses of Megascops are notoriously difficult due to subtle plumage differences among taxa with frequent plumage polymorphism.

Molecular phylogenetics, vocalizations, and species limits in Celeus woodpeckers (Aves: Picidae).

Species limits and the evolutionary mechanisms that have shaped diversification of woodpeckers and allies (Picidae) remain obscure, as inter and intraspecific phylogenetic relationships have yet to be comprehensively resolved for most genera. Herein, we analyzed 5020 base pairs of nucleotide sequence data from the mitochondrial and nuclear genomes to reconstruct the evolutionary history of Celeus woodpeckers. Broad geographic sampling was employed to assess species limits in phenotypically variable lineages and provide a first look at the evolution of song and plumage traits in this poorly known Neotropical genus.

A multi-gene estimate of phylogeny in the nightjars and nighthawks (Caprimulgidae).

Caprimulgidae is a cosmopolitan family of nocturnal and crepuscular insectivorous birds comprising the nightjars, nighthawks, and relatives. Sexual selection and convergence or parallelism in plumage and behavior have made it difficult to discern evolutionary relationships in this group. In order to provide a framework for comparative studies of this family, a molecular phylogeny was reconstructed using mitochondrial cytochrome b, and nuclear c-myc and growth hormone DNA sequences.

Evolutionary history of woodpeckers and allies (Aves: Picidae): placing key taxa on the phylogenetic tree.

We analyzed 2995 base pairs of nucleotide sequence data (nuclear beta-fibrinogen intron 7 and mitochondrial cytochrome b and ND2 genes), using parsimony and model-based approaches to infer phylogenetic relationships of the woodpeckers and allies, yielding novel hypotheses for several critical gaps in the knowledge of picid phylogeny. We tested the monophyly of sub-families within the Picidae, and sampled from widely distributed and diverse genera (Celeus, Colaptes, Dryocopus, Melanerpes, Picoides, Picumnus, Sasia, Piculus, and Picus). Relationships of three poorly known Southeast Asian genera (Dinopium, Reinwardtipicus, and Blythipicus) were also examined, revealing unexpected sister relationships.

West Nile virus survey of birds and mosquitoes in the Dominican Republic.

We report West Nile virus (WNV) activity from a new area on Hispaniola, in the vicinity of Monte Cristi National Park in northwest Dominican Republic. Specific anti-WNV antibodies were detected in 12 of 58 (21%) resident birds sampled in March 2003, representing six species in the orders Cuculiformes (cuckoos), Strigiformes (owls), and Passeriformes (song birds). This seroprevalence is the highest reported from any site in the Caribbean Basin.

West Nile virus transmission in resident birds, Dominican Republic.

We report West Nile virus (WNV) activity in the Dominican Republic for the first time. Specific anti-WNV antibodies were detected in 5 (15%) of 33 resident birds sampled at one location in November 2002. One seropositive bird was <4 months old, indicating a recent infection.