Demographic and Life-History Responses of Rhinella arenarum to Road-Associated Environments

Abstract

The global decline of amphibians is linked to habitat loss, with urbanization androads as major threats. Roads fragment habitats and introduce stressors like pollution,temperature changes, and non-native predators. Despite growing awareness, studiesin Latin America are scarce. In this study, we examined life-history traits of Rhinellaarenarum from four sites in central Argentina that differ in urbanization intensity nearroads. We analyzed snout–vent length (SVL), age, growth, size at maturity, and longevityin reproductive individuals. Sexual size dimorphism was present across sites, with femalesconsistently larger than males. Moderate variation in SVL and age structure was observedamong populations, with smaller and generally younger individuals in sites with mediumto-high urbanization. In contrast, individuals from the least disturbed site tended to showbroader age ranges and greater longevity. Growth rates were also slower in the mosturbanized site. While differences were moderate and sample sizes limited, these patternssuggest that urban-associated factors may influence demographic traits in R. arenarum.These findings contribute to our understanding of how human-altered environmentsmight affect amphibian populations and highlight the need to distinguish between naturalgeographic variation and anthropogenic impacts on amphibian populations.