Matching the largest Neotropical primates with their food resources: Rapid suitability declines in light of climate change

Abstract Anthropogenic climate change affects species distribution and population dynamics. For mostly frugivorous and forest-dependent primates, such as Brachyteles (hereafter muriquis), shifts in plant distributions may alter future resource availability. We evaluated the effects of climate change on the climatic suitability of B. arachnoides and B. hypoxanthus and 46 of their most frequently recorded food plants. We modeled and projected current and future climatic suitability for both primates and plants, assessing suitability, geographic distribution, overlap between primates and plant distributions, and plant richness per pixel. Muriquis had higher suitability values in current scenarios than in future scenarios, with the highest declines predicted for B. hypoxanthus under the 2060 high-emission scenario (67%). In contrast, B. arachnoides had a slight expansion in distribution despite an overall projected reduction in suitability. Suitability and distribution of food plants were projected to decline in the future. Overlap between muriquis and food plant distributions was higher under current climate and decreased with scenario severity. Plant species richness is projected to decline, particularly within B. hypoxanthus range, mainly due to southward shifts in plant species distributions, with highest reductions in the current northern range. Projected declines in suitability for both muriquis and key food plants, combined with ongoing habitat loss, threaten this endangered genus. Enriching and connecting forest fragments with key food species is the main strategy for maintaining population viability and supporting movement under climate change.