Age, body size, and growth of Boana cordobae (Anura: Hylidae) along an elevational gradient in Argentina

Abstract

Life-history traits of individuals organisms (e.g., longevity, age at sexual maturity, body size, and growth rate) often vary among populations in different environments, including along elevational gradients. We investigated elevational variation in the above variables for Boana cordobae using skeletochronology from 158 individuals in six populations along of an elevational gradient (930 to 2,310 m elevation) in central Argentina. Body size (snout-vent length) was the only variable that differed significantly between sexes, with females larger than males. Males were generally larger and older at higher elevations (females were not analyzed for populations differences due to small sample sizes). Specifically, body size was significantly positively correlated with elevation of the populations, with males from the highest elevation population significantly larger than those at lower elevations. Males at the highest site were also significantly older than individuals at lower elevation. Moreover, the oldest individual was 7 y old in the highest population, and 4–6 y old in the other populations, and age at sexual maturity was estimated at 3 y in the highest population and 2 y in the other five populations.