Selection onVPS13Alinked to migration in a songbird

Animal migration demands an interconnected suite of adaptations for individuals to navigate over long distances. This trait complex is crucial for small birds whose migratory behaviors—such as directionality—are more likely innate, rather than being learned as in many longer-lived birds. Identifying causal genes has been a central goal of migration ecology, and this endeavor has been furthered by genome-scale comparisons. However, even the most successful studies of migration genetics have achieved low-resolution associations, identifying large chromosomal regions that encompass hundreds of genes, one or more of which might be causal. Here we leverage the genomic similarity among golden-winged (Vermivora chrysoptera) and blue-winged (V. cyanoptera) warblers to identify a single gene—vacuolar protein sorting 13A(VPS13A)—that is associated with distinct differences in migration to Central American (CA) or South American (SA) wintering areas. We find reduced sequence variation in this gene region for SA wintering birds, and show this is the likely result of natural selection on this locus. In humans, variants ofVPS13Aare linked to the neurodegenerative disorder chorea-acanthocytosis. This association provides one of the strongest gene-level associations with avian migration differences.

A wood-warbler produced through both interspecific and intergeneric hybridization

Hybridization between divergent taxa can provide insight into the breakdown of characters used in mate choice, as well as reproductive compatibility across deep evolutionary timescales. Hybridization can also occur more frequently in declining populations, as there is a smaller pool of conspecific mates from which to choose. Here, we report an unusual combination of factors that has resulted in a rare, three-species hybridization event among two genera of warblers, one of which is experiencing significant population declines. We use bioacoustic, morphometric and genetic data, to demonstrate that an early generation female hybrid between a golden-winged warbler ( Vermivora chrysoptera ) and a blue-winged warbler ( V. cyanoptera ) went on to mate and successfully reproduce with a chestnut-sided warbler ( Setophaga pensylvanica ) . We studied the product of this event—a putative chrysoptera × cyanoptera × pensylvanica hybrid—and show that this male offspring sang songs like S. pensylvanica , but had morphometric traits similar to Vermivora warblers. The hybrid's maternal parent had V. chrysoptera mitochondrial DNA and , with six plumage-associated loci, we predicted the maternal parent's phenotype to show that it was likely an early generation Vermivora hybrid . That this hybridization event occurred within a population of Vermivora warblers in significant decline suggests that females may be making the best of a bad situation, and that wood-warblers in general have remained genetically compatible long after they evolved major phenotypic differences.

Population trends inVermivorawarblers are linked to strong migratory connectivity

Migratory species can experience limiting factors at different locations and during different periods of their annual cycle. In migratory birds, these factors may even occur in different hemispheres. Therefore, identifying the distribution of populations throughout their annual cycle (i.e., migratory connectivity) can reveal the complex ecological and evolutionary relationships that link species and ecosystems across the globe and illuminate where and how limiting factors influence population trends. A growing body of literature continues to identify species that exhibit weak connectivity wherein individuals from distinct breeding areas co-occur during the nonbreeding period. A detailed account of a broadly distributed species exhibiting strong migratory connectivity in which nonbreeding isolation of populations is associated with differential population trends remains undescribed. Here, we present a range-wide assessment of the nonbreeding distribution and migratory connectivity of two broadly dispersed Nearctic-Neotropical migratory songbirds. We used geolocators to track the movements of 70Vermivorawarblers from sites spanning their breeding distribution in eastern North America and identified links between breeding populations and nonbreeding areas. Unlike blue-winged warblers (Vermivora cyanoptera), breeding populations of golden-winged warblers (Vermivora chrysoptera) exhibited strong migratory connectivity, which was associated with historical trends in breeding populations: stable for populations that winter in Central America and declining for those that winter in northern South America.

RARE BIRDS IN ECUADOR: THIRD REPORT OF THE COMMITTEE FOR ECUADORIAN RECORDS IN ORNITHOLOGY (CERO)

Presentamos nuevos registros de distribución de aves del Ecuador que han sido presentados al Comité Ecuatoriano de Registros Ornitológicos (CERO) entre abril 2014 y agosto 2015. Incluimos reportes de seis especies nuevas para Ecuador (Anas crecca, Thalassarche bulleri, Puffinus puffinus, Morus sp., Numenius americanus y Elaenia strepera), una especie nueva para el Ecuador continental (Fregetta grallaria), cuatro especies con primera documentación en Ecuador (Calidris alpina, Larus argentatus, Stercorarius longicaudus, Tyrannus dominicensis), extensiones considerables de distribución de 14 especies (Podilymbus podiceps, Pterodroma phaeopygia, Charadrius semipalmatus, C. collaris, Bartramia longicauda, Calidris alba, Limnodromus scolopaceus, Phalaropus fulicarius, Stercorarius longicaudus, Sternula superciliaris, Chlidonias niger, Galbula dea, Elaenia spectabilis y Geothlypis philadelphia) y nuevos reportes de 12 especies raras (Aythya affinis, Sula leucogaster, Busarellus nigricollis, Stercorarius chilensis, Chordeiles minor, Psittacara wagleri, Philydor fuscipenne, Muscisaxicola fluviatilis, Pyroderus scutatus, Passerina caerulea, Vermivora chrysoptera y Setophaga castanea) y el primer reporte moderno de Oreopholus ruficollis. Además, presentamos el primer registro en Ecuador de Lurocalis semitorquatus semitorquatus y el segundo registro de la subespecie Petrochelidon pyrrhonota melanogaster. Finalmente, invalidamos los registros previos de Picumnus castelnau, especie que no habita en Ecuador. CERO revisa y actualiza el listado nacional de aves, que en la actualidad alcanza las 1678 especies (1626 confirmadas y documentadas, y 52 no documentadas).