URBANIZATION FILTERS AVIAN COMMUNITIES IN A SEMI-ARID LANDSCAPE

Abstract

Urbanization is increasingly altering habitat structure and environmental conditions, with important consequences for avian communities. This study investigated the effects of urbanization on bird diversity, abundance and functional composition across urban, peri-urban and rural habitats in District Karak, Khyber Pakhtunkhwa, Pakistan. Standardized point-count surveys were conducted across 36 sampling points representing the three habitat categories, while environmental variables including anthropogenic noise, canopy cover, shrub cover and built-up characteristics were recorded. A total of 9,799 individuals representing 38 species and 26 families were recorded. Urban habitats were characterized by greater dominance of disturbance-tolerant species, particularly granivores and omnivores, whereas rural habitats supported a greater representation of insectivorous species. Species richness showed a positive association with canopy cover, while anthropogenic noise was negatively associated with avian richness. Community composition differed substantially among habitat classes (PERMANOVA, R² = 0.720, P < 0.001), indicating strong differentiation of bird assemblages along the urbanization gradient. These findings demonstrate that urbanization influences not only the number of birds present but also the composition and functional structure of avian communities. Maintaining mature trees, shrub vegetation, connected green spaces and relatively quiet habitats may therefore help conserve avian diversity within expanding urban landscapes. The study provides an important empirical baseline for avian conservation and future long-term monitoring in the semi-arid landscapes of District Karak and comparable regions of Pakistan.