Trait-dependent responses of birds and bats to season and dry forest distance in tropical agroforestry
Agricultural expansion and intensification increasingly threaten birds and bats, especially insectivorous species from the tropics. Cacao agroforests in tropical rainforest areas have been shown to support higher bird and bat biodiversity than other land-use systems, but their suitability for tropical dry forest biodiversity remains unclear. We present the first assessment of bird and bat diversity patterns in cacao agroforests inside tropical dry forest landscapes. We investigated the response of bird and bat species richness and abundance to forest distance and season across 12 smallholder, organic cacao agroforests and adjacent tropical dry forests in the Peruvian lowlands of Piura. We found that insectivorous bird abundance and species richness increased with forest distance in the dry but not in the rainy season, indicating the value of cacao agroforests for these birds when resources are scarce in forests.
In the case of bats, we observed more species in agroforests with increasing forest distance independent of season, and the abundance of insectivorous species increased along the gradient. Other dietary groups and forest specialists of both taxa did not vary notably across the forest distance gradient. Our findings point to the relevance of cacao agroforests as alternative habitats for insectivorous birds and bats in tropical dry forest landscapes, especially during the dry season. We suggest that the maintenance of wildlife friendly cacao agroforests, parallel to dry forest conservation and restoration, creates win-win situations for both the conservation of tropical dry forest fauna and the maintenance of related ecosystem services from which cacao smallholders may benefit.
Ocampo-Ariza, Carolina; Maas, Bea; Castro-namuche, Jean P.; Thomas, Evert; Vansynghel, Justine; Steffan-Dewenter, Ingolf; Tscharntke, Teja.