Population density, sex ratio and body size in a population of Salamandra atra atra on the Dolomites

Abstract

Salamandra atra atra is the most widespread subspecies of the Alpine Salamander, both in Italy and in the other parts of the species distribution range. However, in particular for Italian populations, its ecology and demographic parameters are poorly known. We studied biometry (length, mass, body condition index) and demography (population density, sex ratio, proportion of gravid females) of this fully terrestrial salamander in the “Paneveggio-Pale di San Martino” Natural Park in the Dolomites. We used removal methods to estimate abundance on a surface of about 1000 m². Density estimate of adults was 472 salamanders/ha, which falls within the density estimates that are available for this taxon. Sexes did not differ significantly in size and body mass. Body sizes of adults included the maximum sized salamander recorded in Italy. There was a high rate of gravid females (50%), which were comparable in size with non-gravid females. Males and non-gravid females did not show significant differences in their body condition index.