Maximum body size and age distribution in the Italian Stream Frog, <em>Rana italica</em> Dubois 1987 (Amphibia: Anura)

Abstract

Data on mean longevity and age structure of Rana italica are very scanty. Skeletochronological data comparisons with other European brown frogs showed that life span of R. italica is similar to those of other congeneric species. In this study we report the age structure of a population of R. italica from Central Italy with a new record of species maximum size. The study population inhabits a perennial stream in a lowland oak wood. All the individuals were marked by means of toe clipping. Skeletochronological analyses showed that adult age ranged from 3 to 5 years in males and from 2 to 6 years in females with no intersexual difference. In our study, the oldest individual (estimated age was 6 years) was also the biggest (68 mm), representing the new body size record for the species. Previous skeletochronological studies on R. italica have shown that the mean longevity for this species is four years but the maximum age recorded is 5 and 8 years in low and high elevation populations, respectively. The ages recorded for the study population inhabiting a hilly area showed higher average and maximum values than those found in lowland populations.