Biogeography and conservation of non-volant mammals from the Urucum Mountains: a Chiquitano dry forest ecoregion in western Brazil

Abstract

Abstract The distributional data of mammalian fauna are important to reach a comprehensive overview of biogeographic patterns and to highlight regional conservation status, especially in a poorly known region such as the Chiquitano dry forest in western Brazil. Our aims were to survey the mammal species occurring in the Urucum Mountains, located in the southeast end of the Chiquitano forest, compare its species composition to areas elsewhere in different ecoregions, and discuss their conservation statuses. Small mammals were sampled using pitfall and live traps, and medium and large mammals were sampled by direct observation, indirect evidence (e.g. faeces and tracks), and camera traps. Patterns of species composition were compared to other surrounding areas of different ecoregions in South America using multivariate analyses. The results indicated that both faunas have similar biogeographical influences. The Urucum Mountains have an influence on the faunas from the Cerrado, Chaco and Pantanal ecoregions, and only secondarily from forested ecoregions (e.g. Amazon forest). The Urucum harbours a rich non-volant mammalian fauna with species that are widely and restrictedly distributed. The conservation of Urucum Mountains is important because these mountains harbour threatened plant, invertebrate, and vertebrate (mammals) species, which could be suffering due to the mining activity carried out in the region. We stress that the Chiquitano dry forest is unique to western Brazil, situated in a complex biogeographical region, and harbouring a rich and diversified mammal fauna.