Patch- and landscape-scale associations of bird assemblages across urban parks in Mexico City

Résumé fourni par la source

Urbanization poses a significant threat to biodiversity; however, urban greenspaces can serve as critical habitats and refuges for birds. While many studies have examined patch-scale (local) drivers of bird assemblages, fewer have evaluated landscape-scale effects and simultaneously evaluated the associations of patch and landscape scale factors with birds in urban environments. Here, we assessed how vegetation structure, human disturbance and landscape composition and configuration associate with bird abundance, diversity and assemblage evenness in 20 urban parks across Mexico City. We recorded 1,194 individual birds from 56 species, with bird assemblages dominated by few synanthropic bird species. Landscape variables of tree and grass cover were consistently important predictors of bird assemblage metrics. Both tree and grass cover were positively associated with species richness, but negatively with bird abundance and assemblage evenness. Landscape configuration metrics were also significant: greater isolation of tree cover patches was positively related to species richness and assemblage evenness, while greater inter-tree distance within parks was negatively associated with bird abundance. Our results suggest that species richness, abundance, and evenness were independently associated with multi-scale drivers, likely reflecting distinct assembly processes. We conclude that effective urban bird conservation requires goal-specific planning: landscape-scale strategies to enhance green cover and connectivity of tree cover patches for species richness, coupled with patch-scale management for habitat complexity to promote more diverse urban bird assemblages.

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