Editorial: Urban Biodiversity in the Global South

Lucas M. Leveau^1*Laura Pereyra¹Rubén Ortega-Álvarez²

• ¹National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
• ²Centro de Investigación en Alimentación y Desarrollo, A. C., Unidad CEIBAAS, Ciudad de México, Mexico

Several key factors contribute to differences in the relationship between biodiversity and urbanization between these regions. First, cities in the Global North tend to be less densely populated than those in the South (Xu et al., 2020). As a result, they often contain more green spaces and experience lower levels of human disturbance, which can favor biodiversity. For instance, Leveau (2021) found greater bird species richness in urban parks of the Northern Hemisphere compared to the Southern Hemisphere. Secondly, socioeconomic factors play a crucial role. Studies have shown that wealthier neighborhoods tend to support higher biodiversity, partly due to increased vegetation cover and habitat availability (Chamberlain et al., 2020;Villaseñor and Escobar, 2022). Finally, climate and species diversity differ markedly between regions. While most cities in the North are located in temperate regions, cities in the South are more evenly distributed across temperate and tropical areas. These areas harbor greater species richness and distinct species pools (Hawkins et al. 2007) and are likely to experience more significant biodiversity losses due to urbanization (Leveau et al. 2017).This special issue seeks to address the existing geographic disparities in urban ecology research by presenting six contributions from tropical and subtropical regions of South America and Africa. The topics covered include spatial patterns of bird and amphibian diversity (Mathew et al., Demartín et al., Garizabal-Carmona et al.), longterm patterns in bird communities (Leveau), bird behavior (Tellería and Garitano-Zavala), and the potential effects of rodenticides on biodiversity (Jaramillo-Q. et al.). Spatial patterns of bird communities were analyzed in tropical savanna-woodland and evergreen forest by Mathew et al. and Garizabal-Carmona et al., respectively. Mathew et al. focused on species richness, abundance, and composition along a rural-urban gradient, finding that bird abundance and richness declined with increasing anthropogenic structures and noise. Interestingly, the negative effect of noise persisted across all urbanization levels, suggesting that even green areas with elevated noise pollution may experience bird species loss. The authors highlight the importance of incorporating species traits into future studies to better understand bird species responses to urbanization. In this regard, Garizabal-Carmona et al. examined how biological traits affect urban tolerance in birds. They categorized species based on their occurrence frequency across different urbanization levels, considering their presence in the urban core and building cover. Species that avoided urban areas tended to have narrow altitudinal ranges and primarily frugivorous or frugivorous-insectivorous diets. In contrast, species residing in urban areas were more likely to have omnivorous diets. Demartin et al. analyzed taxonomic and functional diversity of amphibians in green areas along an urban-rural gradient. Surprisingly, they found that species richness and functional richness peaked at intermediate urbanization levels. Authors suggest that these habitats have a high environmental heterogeneity, allowing the coexistence of species with varied habitat requirements. In addition, species composition showed significant turnover among green areas, suggesting that species replacement was driven by varying abilities to cope with urbanization pressures.Focusing on long-term dynamics, Leveau analyzed changes in bird communities during 10 years in urban, suburban, and periurban habitats of Mar del Plata, Argentina. He found that species composition changed progressively over time at similar rates in the three habitats. Given the lack of changes in local habitat conditions, these long-term bird composition dynamics appear to be mostly related to regional changes in climate and land use rather than by immediate urbanization effects.Bird behavior in urban areas was explored by Tellería and Garitano-Zavala in the inter Andean valley of Bolivia. They analyzed intraspecific and interspecific playback responses of the territorial Sparkling Violetear hummingbird (Colibri coruscans), finding that it was more aggressive toward other nectarivorous species during the dry season, when nectar resources were scarcer.Lastly, Jaramillo-Q. et al. examined the use of anticoagulant rodenticides (ARs) in Medellín, Colombia, a biodiversity hotspot in the northern Andes. The study assessed the spatial distribution of AR application sites over five years and identified critical risk zones within the city's main ecological structure. More than half of the AR application sites overlapped with key biodiversity areas, posing a serious threat to non-target species, particularly raptors and carnivorous mammals. These findings highlight the need for stricter regulations and toxicological studies to understand the long-term impacts of AR exposure on urban wildlife.Through our special issue, we contribute to expanding the representation of urban ecological research performed in South America and Africa, regions that remain underrepresented in global discussions despite their ecological significance. Moreover, we emphasize the importance of increasing such studies in the Global South, as previously stated by other colleagues (Ortega-Álvarez and MacGregor-Fors, 2011;Muñoz-Pacheco and Villaseñor, 2022;Leveau et al., 2022). Readers are invited to enjoy the set of papers that comprise this issue and we hope to motivate their interest and action in studying the urban biodiversity across the region.