Body size and life history traits of the fire salamander Salamandra salamandra from Poland

Abstract

Abstract The fire salamander Salamandra salamandra is a widespread taxon in Europe, exhibiting great intraspecific diversity in phenotype and life history traits across its geographical distribution. Here, we studied body size, sexual dimorphism, age, growth rate and condition of fire salamanders from the north-eastern margin of its range. In total, 2,102 individuals from 23 populations representing the Polish parts of the Sudetes and the Carpathian Mountains were sampled between 2004 and 2016. Body traits and age showed significant differences between the western (the Sudetes) and eastern (the Carpathians) groups of populations. Salamanders from the Carpathians tended to be longer, heavier and older. Female-biased sexual size dimorphism was found only in the Carpathians. Body condition at the beginning of the season was poor, then increased to reach a peak in early June, and deteriorated toward the end of the season. Age estimated by skeletochronology on phalangeal bones ranged from 2 to 16 years in both females and males, with the highest share of 7- to 9-year-old individuals. Age of juveniles ranged from 1 to 5 years in the Sudetes and from 1 to 4 years in the Carpathians. Growth curves (fitted using von Bertalanffy’s model) were asymptotic throughout the individual lifespans, but exhibited differences between sexes and mountain ranges. Altitude did not explain differences in characteristics of populations living in the two mountain ranges, but these differences most probably resulted from habitat quality (better in the Carpathians) and adverse human impact (higher in the Sudetes).