Data from: Ecological traits explain levels of genetic divergence across an environmental barrier among South American birds

To compare the level of mitochondrial divergence between avian populations
east and west of the open vegetation corridor (OVC), an environmental
barrier that currently isolates the Atlantic Forest from the Andean
forests and Amazonia, and assess whether biological attributes can explain
the patterns of intraspecific variation observed. We estimated net genetic
divergence between populations on opposite sides of the OVC for 71 bird
species based on 727 sequences of the mitochondrial gene COI. Species were
categorized based on three ecological attributes and two morphological
traits. The relationship between divergence and the biological attributes
was assessed through generalized linear mixed models and univariate
analyses. Divergence between populations on both sides of the OVC tended
to be low, implying that nearly all diversification events took place
within the Pleistocene, and discordant among species. Differences in
habitat specialization were by far the most relevant to explain this
discordance, with significantly higher intraspecific distance among forest
specialists than among species capable of inhabiting open environments.
The relative importance of all other traits was notably lower, but
understory species that feed on animals showed a significantly higher
genetic divergence across the OVC than those with a plant-based diet that
forage in the canopy. We found no association between genetic distance and
morphology. Ecological attributes can explain the pattern of discordant
mitochondrial divergences between populations on both sides of the OVC.
Our findings emphasize the need for more comparative studies that take
into account functional traits.