Cattle grazing facilitates the species richness and abundance of temperate understory birds and alters their activity patterns

Understanding free-ranging livestock-wildlife interactions in shared forest landscapes is critical for balancing the conflict between human exploitation of natural resources and wildlife conservation. However, little is known about the responses of ground-dwelling birds to grazing in temperate forests. We compiled a camera-trapping dataset of 1446 detections of 22 bird species over 6363 trap days from June to October 2020 at 25 cattle-grazed forest sites and 22 ungrazed sites, from which we assessed the relative impacts of cattle grazing, vegetation and predator (red fox Vulpes vulpes and leopard cat Prionailurus bengalensis) presence on the richness, site use, and diel activity patterns of understory birds (including frugivores and insectivores) in Northeast China. Our results revealed that ground-dwelling forest bird community assemblages were similar in both forest habitats; however, bird species richness was significantly greater in grazed forests than in ungrazed forests. The bird species richness increased with increasing plant diversity (Shannon index) in grazed forests and was positively associated with fox and leopard cat presence. The site use intensity of both frugivorous and insectivorous birds was positively associated with plant diversity in grazed forests, but negatively in ungrazed forest. Compared with insectivorous birds, frugivorous bird activities were significantly and positively associated with fox and leopard cat presence and an increase in leaf area index. Temporally, we found that diel activity significantly changed with increasing cattle grazing pressure for frugivorous birds. In contrast, insectivorous birds had similar daily activity patterns but shifted their activity peaks toward dawn in grazed forests. This work highlights that managing grazing practices and their effects on vegetation can positively affect temperate forest bird species richness and abundance.