Contrasting evolutionary histories: speciation across the open vegetation corridor.

LAVINIA OBLANCA, P. D,; TUBARO, P. L.; CAMPAGNA L.; BARREIRA, A. S.; LIJTMAER, D. A.

Puerto Iguazú, Misiones

Congreso; Ornithological Congress of the Americas - XVII RAO - XXIV CBO - XCV AFO; 2017

Association of Field Ornithologists - Aves Argentinas - Sociedad Brasilia de Ornitología

The Neotropics possess the highest avian diversity of the world with over 3,000 breeding species. Most of this richness is found in rainforests, which include some of the most biodiverse regions in the planet like the Amazonia, the Atlantic Forest and the Yungas Forest. We studied the factors and processes that have promoted diversification in two species of passerines (Ramphotrigon megacephalum and Pipraeidea melanonota) that inhabit South American forests. Then we compared and integrated the results with those of our recently published analysis of the Neotropical forest specialist Habia rubica. These species have disjunct, overlapping distributions that include allopatric populations in the Atlantic Forest and the Yungas-Amazonia complex. We applied an integrative approach combining genetic (mitochondrial and nuclear markers), phenotypic (plumage coloration) and behavioral (vocalizations) evidence. The results showed that the diversification processes of each of these species possess their idiosyncratic features, but were also shaped by a common evolutionary driver: the open vegetation corridor that currently isolates the Atlantic Forest from the Yungas-Amazonia complex. However, even this shared factor has affected these species in different manners. The differences found among the phylogeographic patterns of these species seem to be associated with their distinct ecologies and dispersal abilities, which resulted in contrasting evolutionary histories across the corridor. In conclusion, our work supports the idea that the diversification of the Neotropical avifauna cannot be restricted to a particular temporal period or explained by a single evolutionary driver, and that even the influence of major diversification factors could vary across species.