Avian Diversity and Conservation Value of the Gölköy-Yumrukaya Wetland: A University Campus as a Biodiversity Hotspot on the Urban Fringe

Abstract

Urbanization and habitat fragmentation increasingly threaten global avian biodiversity, leading to biotic homogenization and declining community heterogeneity. University campuses, particularly those with wetland ecosystems, are emerging as important refugia for bird species. This study examines avian diversity, dominance patterns, and community structure across the Gölköy-Yumrukaya (GY) wetland and surrounding campus habitats of Bolu Abant İzzet Baysal University, Türkiye. Between 2017 and 2023, systematic field surveys recorded 173 bird species from 45 families. The results underscore the ecological significance of the GY wetland as a complementary habitat, particularly for summer visitor and passage migrant species. Seasonal analyses reveal peak species richness and diversity during the breeding and migration periods, while winter exhibits lower diversity and increased dominance concentration, especially among urban-adaptive species. The study highlights the importance of artificial wetlands in fragmented landscapes, provided they maintain ecological connectivity with natural wetland systems. Additionally, a newly proposed ecological metric, the Heterogeneity Ratio (Hr), is introduced, offering a higher-resolution assessment of community structure dynamics compared to traditional diversity indices. Due to its sensitivity to temporal fluctuations in species abundance and evenness, Hr is recommended as a valuable tool for future biodiversity assessments.