Regional Context Mediates The Response Of Mexican Primates To Landscape Structure In Fragmented Rainforests

Land use change is a major threat to species' persistence. Yet, landscape attributes that shape populations remain poorly understood. Landscape-scale forest cover and matrix quality can favor population persistence, while forest fragmentation per se usually has weak effects on species. The impact of these spatial changes can, however, be influenced by the regional context. To test these hypotheses, we assessed the abundance and immature-to-female ratio (reproductive success) of two endangered howler monkeys species and their relationships with forest cover, matrix quality and forest fragmentation (forest patch density) in four Mexican regions with different deforestation levels. Responses to landscape structure differed among regions. Forest loss was negatively related to primate abundance in two regions. Yet, in the most deforested region, forest loss was positively related to the immature-to-female ratio. Matrix quality was negatively related to monkey abundance and positively related to immature-to-female ratio in regions dominated by arboreal matrices. Fragmentation was negatively related to abundance but positively to immature-to-female ratio in the best preserved region, and negatively related to immature-to-female ratio in a region dominated by treeless matrices. Thus, given that the regional context influences the effects that landscape attributes have on primates, different conservation strategies could help maintain the populations of these arboreal mammals in different regions. Preventing forest loss and restoring forest cover are paramount in highly deforested regions. Increasing matrix quality is highly valuable, especially in regions dominated by treeless matrices. Finally, increasing the number of patches through restoration can have better conservation outcomes in more forested regions.