Distribution Modelling and Habitat Requirements of Micronycteris sanborni (Phyllostomidae) across the South America Dry Diagonal

Abstract

Micronycteris sanborni is an insectivorous bat known from dry phytogeographic domains in South America, although its distribution range is not yet well known. Here, we modelled the distribution of this species based on seven bioclimatic and vegetation predictors associated with its occurrence, using 26 sites where the species was recorded in the Caatinga (16), Cerrado (7), Chiquitano Dry Forest (2) and Pantanal (1). We used four different algorithms to build an ensemble distribution model, to estimate habitat suitability throughout its geographic occurrence and the area of habitat available inside protected areas. Our models showed excellent performance and highlighted the main importance of four environmental variables (other mixed trees, deciduous broadleaf trees, evergreen broadleaf trees, and precipitation of driest quarter), which accounted for more than 80% of the species presence probability. The distribution model indicated the potential occurrence of M. sanborni consistently across the dry diagonal of South America, but adequate habitat areas covered mainly the Caatinga and the northeast of Cerrado rather than the southwest, where suitable habitats were scattered and discontinuous. Less than 10% of the total habitat predicted for M. sanborni corresponded to protected areas. Our results support that M. sanborni mostly depends on woody and less dry environments across the South America dry diagonal, which raises concerns about its vulnerability due to high deforestation in the southwest and because severe dryness is forecast for the coming decades in the Brazilian northeast.