Vegetation structure modulates insectivorous bat assemblages in West African cocoa agroforests

Agricultural expansion is a major driver of biodiversity loss in tropical regions. Agroforestry systems may help reconcile production with conservation, but it remains unclear how their design can best support biodiversity outcomes. This is particularly relevant in West Africa, which produces ca. 70% of the world’s cocoa, yet where the biodiversity conservation consequences of agroforestry structure remain poorly understood. Bats are a useful model taxon for assessing these impacts due to their sensitivity to vegetation structure and the provision of key ecosystem services. To address the research gap concerning the impact of vegetation structure on aerial insectivorous bat assemblages in West Africa, we combined passive acoustic monitoring with field-based vegetation surveys and drone-derived canopy metrics across 38 cocoa farms spanning a gradient of structural complexity in the Ashanti Region of Ghana. Recorded bat activity was positively associated with shade tree density, increasing by 6.64% for every ten additional shade trees per hectare, while shade tree height was associated with variation along one NMDS axis. Sonotype richness showed no significant relationship with vegetation structure. Open-space sonotypes accounted for 89.35% of recorded bat passes, although differences in acoustic detectability among guilds preclude interpreting this pattern as evidence of their relative abundance or ecological dominance. Our findings indicate that farm-level vegetation structure is associated with guild-specific patterns of bat acoustic activity and sonotype composition in cocoa agroforests. Together with existing evidence, our results support the role of agroforestry as complementary to, rather than a substitute for, forest protection. Policies and sustainability interventions that promote relatively high shade tree densities and structural heterogeneity, alongside the protection of remaining forests, could contribute to biodiversity conservation and the maintenance of bat-mediated ecosystem services.