Reevaluation of the Geographical Distribution of Bradypus tridactylus Linnaeus, 1758 and B. variegatus Schinz, 1825

Abstract

The confusing nomenclatural history of Bradypus tri- dactylus and B. variegatus has led to incorrect taxo- nomic attributions through time and, consequently, errors in range map inferences. In this note, we reevaluate the geographical distribution of B. tridac- tylus and B. variegatus based on museum specimens, field observations, and literature records of sloths. Our analyses revealed considerable range differences when compared to previous distribution inferences. For instance, B. tridactylus is restricted to the Guyana shield, and in Brazil it is only found north of the Amazon River and east of Negro River. Additional analysis using an Ecological Niche Modeling tech- nique, and considering only bioclimatic and topo- graphic variables, predicted that potential suitable areas for B. tridactylus are mostly limited by cold tem- peratures. However, when comparing our model to the present time distribution of forests we observed that the suitable area for B. tridactylus may be smaller than predicted by the model.