Landscape context influences local management effects on birds and bats in Amazonian cacao agroforestry systems

Abstract

Agricultural expansion and intensification are major drivers of biodiversity loss, particularly in tropical regions. Cacao agroforestry systems can both support and benefit from high levels of biodiversity via associated pest control services from birds and bats, although their potential to do so likely depends on local management and the landscape context. However, how interactions between local-scale agroforestry practices and landscape-scale habitat features shape bird and bat communities in these systems remains poorly understood. We studied birds and bats in 28 smallholder cacao agroforests in the Peruvian Amazon, comparing two regions with contrasting levels of agricultural intensification. We analyzed how local tree diversity and canopy cover interact with surrounding landscape tree cover and regional agricultural intensity to influence species richness and community composition. Results showed that local tree diversity increased bird richness, but only in the intensively farmed region. Local canopy cover had contrasting effects: it negatively impacted bird richness, abundance, and bat activity in more open landscapes (<55 % tree cover), but positively in forested landscapes (>80 % tree cover). Notably, these interactions were significant when considering the landscape tree cover at small spatial scales (250 m), but not at 500 m or 1000 m. Our findings highlight the importance of adapting cacao agroforestry management to the surrounding landscape. Retaining high local canopy cover supports flying vertebrate diversity and associated ecosystem services in forested landscapes, while restoration of landscape tree cover could enhance bird and bat populations that may contribute to pest suppression services in deforested areas.