Urban form shapes bird niches: insights from the European green capital 2024

Abstract

This study underscores the critical importance of integrating biodiversity considerations into urban planning, demonstrating how diverse urban structures can support bird populations while contributing to the resilience of urban ecosystems. The research investigates whether significant differences exist among urban configurations in terms of species richness and individual abundance. The proposed urban configurations—historic centres, open blocks, and closed blocks—were examined in Valencia, Spain. Urban composition data were obtained from open-access platforms, and bird information was sourced from the SACRE citizen science program. Data were organized hierarchically and analyzed using Generalized Linear Mixed Models (GLMMs), complemented by the AIC criterion and QQ plot residuals. The study recorded 23 bird species, with the lowest richness observed in historic centres (13 species). Significant ecological differences were found among birds that feed in the air, in trees and shrubs, and those that nest in buildings. The findings highlight the ecological value of historic buildings, which offer critical nesting opportunities. Among the three urban habitat types, the most common species were the common swift (Apus apus), rock pigeon (Columba livia), house sparrow (Passer domesticus), and Eurasian collared dove (Streptopelia decaocto). Additionally, this research discusses the decline of European swift populations and house sparrow, linking it to modern building practices that reduce nesting sites. By emphasizing the ecological consequences of urban development and the need for biodiversity-friendly measures, this study contributes to understanding how urban planning can promote conservation and mitigate biodiversity loss in rapidly changing urban landscapes. © The Author(s) 2025.