Glacial cycles promote the diversification of the Southern Lapwing (Vanellus chilensis) and a secondary contact zone

CAMPAGNA, LEONARDO; TUBARO, PABLO L.; RODRIGUEZ CAJARVILLE, MARIA JOSE; LIJTMAER, DARIO A.; BUKOWSKI, BELÉN; CABANNE, SEBASTIÁN

No corresponde - virtual

Congreso; VII North American Ornithological Conference (virtual); 2020

American Ornithological Society y otras 6 sociedades de ornitología de América

The diversification patterns of the birds of southern South America, and particularly Patagonia (southern Argentina and Chile), have been less studied than in other regions of the Neotropics. We analyzed the evolutionary history of the Southern Lapwing (Vanellus chilensis), a widespread species characteristic of Neotropical open habitats, focusing on the differentiated mitochondrial lineage previously found in Patagonia and the role played by glacial cycles in its differentiation. We performed a phylogenetic/phylogeographic analysis including the four recognized subspecies, using mitochondrial and genomic DNA, and also studied their vocalizations. The results suggest that the main diversification event within V. chilensis occurred approximately 600,000 years ago, resulting in a marked phylogeographic structure with 1.5% mitochondrial genetic distance between the Patagonian lineage and the rest of the species. The genomic analyses confirmed this differentiation, showing considerable gene flow between the two lineages and supporting the presence of a contact zone in northern Patagonia. Vocalization were significantly different between the two lineages, and those recorded in the contact zone were intermediate in their temporal and frequency characteristics. Taken together, our results confirm that the populations from southern South America are clearly differentiated from the rest of the species and suggest that this differentiation occurred due to the isolation of the Patagonian populations in refugia during the Pleistocene glaciations, followed by an expansion from these refugia and the establishment of a zone of secondary contact in northern Patagonia. Our study highlights the importance of glacial cycles in southern South America as drivers of avian diversification.