Impacts of climate change and habitat loss on the distribution of the endangered crested capuchin monkey (Sapajus robustus).

The crested capuchin monkey (Sapajus robustus) is endemic to the Atlantic Forest and its transition areas within Cerrado in Brazil. The species is currently threatened by habitat loss and has been classified as endangered by the IUCN Red List of Threatened Species since 2015. We used ecological niche models built with MaxEnt to predict the potential impact of climate change on the distribution of this species. The models were projected onto the reference climate, considering six climate scenarios (three Global Climate Models and two Representative Concentration Pathways) from IPCC for 2050 and 2070. We showed that while the amount of suitable area is expected to change little across the species' range in most evaluated climate scenarios, climatic conditions may significantly deteriorate by 2070 in the pessimistic scenario, especially in currently warmer and dryer areas to the west. As seen on other capuchin monkeys, the potential use of tools by crested capuchins may increase the chances of the species adaptation to novel harsher environmental conditions. The major negative impacts across the species range also include habitat loss and fragmentation so that the conservation of the species relies on the protection of the forest remnants in the center of its distribution, which can harbor populations of the species in current and future climate scenarios.

Fragmentation dynamics and loss of area of potential occupancy within the distribution limits of the endangered crested capuchin monkey (Sapajus robustus).

Habitat loss is one of the main threats to biodiversity. Fragmentation resulting from this process may restrict available habitat for primates, limiting their persistence in a given region. In this study, we aimed to quantify deforestation and fragmentation by identifying forest remnants capable of maintaining populations of the endangered crested capuchin monkey (Sapajus robustus) within its distributional limits in the states of Bahia, Espírito Santo, and Minas Gerais, Brazil. We used Landsat images from 1985 to 2010 to generate three time-interval mosaics classified by natural and non-natural vegetation. We then calculated the size of the forest remnants and the distance of each fragment of natural vegetation to its nearest neighbor. Between the first (1985-1990) and second (1995-2000) mosaics there was a vegetation loss of 41.4%, and between the second and third (2005-2010) mosaics there was a natural vegetation gain of 1%. The third mosaic showed smaller and more isolated fragments in comparison to the first mosaic. Across the three periods, Bahia was the state with the highest rate of deforestation. While Espírito Santo had fewer identified forest remnants, it retained the most natural vegetation within these small fragments. The landscape within the currently recognized distributional limits of the crested capuchin monkey is dominated by agriculture and livestock. Both decreasing fragment size and increasing species isolation by distance between fragments can negatively affect primate populations, increasing their risk of extinction. Isolation makes it difficult for migration and recolonization events to occur. Therefore, habitat restoration should be prioritized to reduce isolation between populations. Our findings may serve as a resource for future conservation efforts and management of the crested capuchin monkey.