Fig 1. The distribution of 260 studied localities.

The limits of the Caatinga dry vegetation, the Cerrado savannah, the Amazon and the Atlantic Forest dominions are shown. The inset map shows the location of the location of the studied region in South America. Note that a few studied localities were located just outside the Caatinga limits. They were included in the analyzes due to small-scale uncertainties regarding the exact location of the Caatinga limits ([67], for instance, adopt somewhat distinct southern and north-western limits), and because they shared the typical thorn dry forest physiognomy and seasonally dry climate that predominate in most of the Caatinga dominion. Their exclusion did not alter the results significantly (data not shown).