Intrinsic and extrinsic correlates of range change in mammals

Abstract

The global conservation status of all mammals has been evaluated for the first time in 2008, and in 2010 Hoffman et al. (2010) made a retrospective assessment related to the year 1996. A recent study by Di Marco et al. (2014) assigned species to a threat category in 1970, based on information in the published literature. Despite the great efforts made in understanding the situation of mammals in the recent past, most of the existing studies lack information on changes in the spatial distribution of the species. In this study we aimed at filling this gap by collecting data on the distribution of mammals in the 1970s, when this information was available and reliable, and we then compared the past range of species to their current range. We identified the areas gained or lost by each selected mammal, and analysed the relationship between the loss or gain of part of the distributional range and a set of intrinsic traits and drivers of threat. For most of the species that experienced a range reduction, the increase in human population and pressure have been the major drivers of decline. This work will help to understand the success of past and current conservation actions on species and also the identification of sites potentially exposed to human influence in the near future.