Assessment of pest control services by vertebrates in Nigerian subsistence maize farms

Global conversion of patches of natural vegetation into agricultural land is reducing the ecosystem services provided by natural patches dwelling species to farmers. For sub-Saharan African subsistence farmers, such a reduction in pest control services by birds may be a significant disadvantage. Here we explored to what extent birds provide pest control services to the staple crop maize (Zea mays) on small subsistence farms on the Mambilla Plateau of Taraba State, Nigeria. We used exclosure experiments (maize crops with and without birds) to model how birds influenced crop yield. We found that excluding birds from maize significantly reduces crop yield, although the lack of a direct correlation between bird abundance and crop yield suggests that other taxa, such as bats, may also be important pest predators. Our results suggest that in this subsistence farming landscape, natural pest control of maize from vertebrates does occur, but further research is needed to understand the specific control agents and the role of patches of natural vegetation as habitat for them.