Reevaluation of the Geographical Distribution ofBradypus tridactylusLinnaeus, 1758 andB. variegatusSchinz, 1825

Abstract

The confusing nomenclatural history of Bradypus tridactylus and B. variegatus has led to incorrect taxonomic attributions through time and, consequently, errors in range map inferences. In this note, we reevaluate the geographical distribution of B. tridactylus 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 technique, and considering only bioclimatic and topographic variables, predicted that potential suitable areas for B. tridactylus are mostly limited by cold temperatures. 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.