The need for IUCN species distribution update - the case from a large threaten ungulate in Southwest China

Abstract

Species distributions are one of the fundamental factors needed for understanding and conserving wildlife. While the IUCN Red List of Threatened Species is the primary applied reference for biodiversity conservation, limitations in data availability and analyses of the distributions of some species may limit accurate threat classification assessments and conservation recommendations. Improving the accuracy of species distributions in light of growing data and analytical methods is a key step to increasing the efficacy of the Red List. In this study, we reassessed the distribution of takin (Budorcas taxicolor tibetana), a large ungulate in Sichuan Province, southwest China , classified by the IUCN as vulnerable. Using species distribution models and reported habitat requirements, we updated the takin distribution map. Our updated distribution range in the study area (79,449km2) was 61.31% of current distribution range (CDR) on the IUCN red list. This reduction was in large part due to the inclusion in the CDR of substantial areas of lowland plains, high human disturbance, and non-forest habitat, which provide no suitable habitat for takin. According to our results, suitable takin habitat covered 18.97% of the CDR, suggesting a substantially over-estimated distribution. However, there are high proportions of habitat (40%) still covered by the nature reserve network, indicating the importance of protected areas (PAs) in conservation threaten species. We recommend that experts apply the basic approach presented herein to update the Red List distributions for more species to increase the accuracy of assessments and resulting conservation applications.