The Role of Campus as an Urban Multiuse Protected Area in Bird Nocturnal Roosting Habitat Function

Campus green spaces are vital components of urban green infrastructure, providing crucial habitats for wildlife, especially birds, in fragmented urban environments. However, their role in supporting nocturnal bird habitats remains underexplored. This study investigates nocturnal bird roosting habitat selection in the green spaces of a university campus in western China. The seasonal surveys were conducted along fixed routes to track the distribution of birds' nocturnal roosts on campus. Infrared hotspots were detected using thermal imaging night-vision cameras. Roosting tree species were identified, and roosting point heights were estimated visually. The survey results identified eight nocturnal roosting sites and common campus vegetation, which were used for in-depth analysis of bird roosting habitat characteristics. The study found that: (1) Campus birds preferred Ficus concinna and Ficus virens (93% selection rate), especially those with dense foliage and high concealment. (2) Birds showed seasonal variations in their roosting positions. In summer, they were more dispersed, while in autumn and winter, they concentrated vertically. Horizontally, they preferred the outer ends of branches away from the trunk. (3) The number of infrared (thermal) hotspots corresponding to birds' nighttime roosts was significantly higher in summer than in the other seasons. Based on these findings, the paper proposes strategies to optimize campus green space management, including the targeted planting of tree species, adjustments to vegetation structure, and the reduction of excessive branching to enhance nocturnal roosting sites. This research offers valuable insights into the nocturnal behavior of urban birds and provides practical recommendations for urban planners and conservationists to promote biodiversity-friendly urban design and management policies.