Abstract
Climate change is one of the main drivers of shifts in species distributions. Ecological niche models (ENMs) are valuable tools for assessing these effects and informing conservation efforts. This study employed ENMs to assess the impact of climate change on the present (from 1970 to 2000) and future (up to 2100) climate suitability patterns of the black-and-gold howler monkey (Alouatta caraya [A. caraya]), which is facing serious threats due to habitat changes and disease, especially in the southernmost part of its range. We also evaluated the effectiveness of current protected sites for the species' conservation in the future. For each 20-year interval, we used seven different algorithms and reconstructed a consensus map using ensemble techniques. We then reevaluated the geographical patterns of habitat suitability, accounting for dispersal restrictions and fragmentation history. Our results suggest that areas of high habitat suitability for A. caraya may be much smaller than the geographic distribution reported by the IUCN, with future projections predicting a continuous decrease in suitable areas from 2021 to 2100. Furthermore, most sites with high suitability for A. caraya are located outside protected areas, with < 11% of its potential distribution range currently under protection. The extent of protected areas further drops by nearly 50% when only areas that remain suitable for A. caraya over the next 80 years (refuges) are considered. Moreover, areas with higher suitability indices are clustered within the Chaco and Pampa regions, which have been subjected to significant habitat conversion during the last 35 years. Therefore, climate change and habitat conversion pose a significant threat to A. caraya's effective conservation, warranting a review of its conservation status.