Effects of the Grazing Exclusion Policy on Pheasant Nesting Success and Predation Risk in the Protected Areas of Southwestern China 森林禁牧对中国西南保护区雉类繁殖成功率与捕食风险的影响研究

Abstract

Grazing has a profound impact on forest ecosystems and biodiversity. In recent years, grazing exclusion has been widely implemented as a conservation policy in many protected areas. However, its effects on wildlife populations, particularly on the reproductive ecology of pheasants, remain insufficiently explored. This study focuses on the Wanglang National Nature Reserve in Sichuan Province. Using data from before (2018) and after (2024) the implementation of an exclusion policy, we combined infrared camera monitoring and simulated nest experiments to assess the influence of grazing exclusion on pheasant nesting success and predation risk. Historically impacted by grazing, the Wanglang Reserve is located in the Himalaya–Hengduan Mountains of southwestern China, a global hotspot for pheasant diversity and a key climate refugium. Grazing exclusion was gradually implemented beginning in 2017, providing an ideal natural experimental site for this study. Our results show that pheasant nesting success significantly declined after exclusion, whereas both predator diversity and predation frequency increased. These findings suggest that grazing exclusion may indirectly reduce reproductive success by altering predator activity and distribution. Although exclusion promoted vegetation recovery and improved habitat conditions, it did not effectively reduce short-term predation risk. This study provides important scientific evidence regarding post-exclusion wildlife dynamics in forest ecosystems and reveals the limitations of the umbrella species strategy in predicting wildlife responses to human disturbance. Future research should incorporate detailed temporal and spatial analyses of wildlife‒livestock interactions, along with long-term monitoring data to optimize grazing exclusion policies and provide theoretical support for effective forest ecosystem management and wildlife conservation.