The Ecological Price of Segregation: Socioeconomic Stratification Structures Urban Bird and Vegetation Distribution

Rodrigo Mutis , Sara Gabriela Acosta-Morales

As income inequality rises, cities do not merely become less equal in aggregate; they also sort residents into increasingly separate neighborhoods, a spatial process known as socioeconomic segregation. Building on a companion study that documented the luxury effect in Bogotá using cadastral land value (Mutis & Armenteras, 2026), this analysis asks a distinct question: does the city's institutionalized stratification system—the official six-tier "estratos" that determine utility subsidies, social stigma, and municipal investment—have an ecological signature of its own? We analyzed 118,447 eBird records (2010–2024) covering 258 species, spatially joined to cadastral strata. The three highest strata (4–6), occupying only 26.4% of the city's urban area, accounted for 52.3% of all bird occurrences, while the three lowest strata (1–3), covering 73.6% of the area, accounted for 47.7%. Species-level analyses revealed heterogeneity: habitat generalists occurred across all strata, wetland species clustered in strata 3–4, and forest specialists concentrated in stratum 6, coinciding with the Eastern Hills. A complementary analysis of the Normalized Difference Vegetation Index (NDVI) across 5,315 urban parks showed vegetation cover rising steadily from lower to higher strata (Tukey post-hoc, p < 0.05), positively correlating with bird richness (β = 72.7, p < 0.001). Together with the companion land-value analysis, these results suggest that in Bogotá the boundaries separating human social worlds also partition its avian communities and the vegetation that sustains them, with direct implications for equitable green-infrastructure planning in highly segregated cities of the Global South.