Avaliação do potencial invasivo de Saguinus midas na extensão de ocorrência do criticamente ameaçado Saguinus bicolor

Abstract

Saguinus bicolor is one of the most endangered primate species in the Amazon, mainly due to threats related to human activities, such as deforestation and habitat fragmentation. However, the invasion of its small range, one of the smallest known for an Amazonian primate, by a likely competing “sister” species Saguinus midas, has been identified as a serious threat to the long-term survival of Saguinus bicolor. Therefore, assessing the potential of a species to expand its range into the range of an endangered species is essential for science-based conservation and environmental management. In this study we investigated the invasion potential of S. midas into the extent of occurrence of S. bicolor, evaluating habitat suitability for both species based on a set of ecologically relevant environmental variables. We also applied a similarity test to assess the niche overlap between the two species. We showed that most of the extent of occurrence of S. bicolor has a greater habitat suitability for S. midas than for S. bicolor and we found high niche similarity between the two species. The results indicate a high potential of invasion by S. midas into the current already small range of S. bicolor, corroborating previous studies. Our findings also indicate that S. midas is probably the most generalist species, corroborating studies that indicate a potential competitive advantage of S. midas over S. bicolor. Our analyses indicate that only 889 km2 or 10,6 % of the current extent of occurrence of S. bicolor is likely suitable and available for the long-term survival and persistence of S. bicolor. We also show that a large portion of the extent of occurrence of S. bicolor, that is relatively more suitable for S. bicolor than for S. midas is urban, and paradoxically these areas may play a critical role in the long term survival of S. bicolor. Although the prospects for the long-term persistence of S. bicolor are complicated, we present proposals for priority and multifaceted actions, which, if developed, could help in the conservation of the species.