Seasonal effects of farmer-managed livestock grazing exclusions on bird communities in Burkina Faso.

Anthropogenic activities such as livestock grazing and deforestation are primary causes of land degradation in drylands such as the Sahel Zone of Africa, threatening the livelihoods of rural communities and biodiversity. To restore degraded habitats, measures such as farmer-managed livestock grazing exclusion, where the native vegetation is protected and can naturally regenerate, have been implemented. Yet the benefits of such measures for biodiversity remain poorly understood, especially in regions that experience strong seasonality. Here, we used passive acoustic monitoring to study how livestock grazing exclusion affects the avifauna at the community and species level across the dry and wet seasons. Focusing on an NGO-driven initiative that has implemented a large network of small-scale farmer-managed grazing exclusions in Burkina Faso, we show that species richness and occurrence probability of most bird species were higher in grazing exclusions compared to control sites. These positive effects were more pronounced during the dry season, suggesting an ecological refuge effect when resources are limited. Despite overall positive effects on birds, we found species- and guild-specific responses to grazing exclusion with species positively or negatively affected. While grazing exclusions typically had negative effects on open-habitat specialists, frugivores, insectivores, species associated with woodlands, and Afro-Palearctic migratory species were winners. Grazing exclusions, even at small scale, show a great potential to combat desertification, reverse land degradation and halt biodiversity loss thereby being in line with the UN Decade on Ecosystem Restoration. Yet, we emphasize the need for further studies including a socioeconomic perspective to ensure durable benefits for rural communities.