Age and growth of the sand lizards (Lacerta agilis) from a high Alpine population of north-western Italy

摘要

We studied growth and longevity of Lacerta agilis from a sample (34 adults and 2 small-sized juveniles) of a population living at high altitude in north-western Italy using skeletochronological method. Snout vent length (SVL) mean of males did not significantly differ from that of females although the latter were in average bigger (SVL ± SD, males: 69.3 ± 7.1 mm, n?=?11; females: 73.9 ± 9.7 mm, n?=?22; Mann-Whitney U-test, U?=?1.76, P?=?0.077). Age ranged from 2 to 4 years (mean age ± SD?=?2.3 ± 0.2) in males and from 2 to 3 years in females (mean age ± SD?=?2.59 ± 0.5 years). Age mean did not significantly differ between the sexes (Mann-Whitney U-test, U?=?1.35, P?=?0.174). The two juveniles were 30 and 32 mm in SVL and both were 1-2 months old. In both sexes, a significant positive correlation between SVL and age was recorded although weakly significant for males (Spearman’s correlation coefficient, males: rs?=?0.70, P?=?0.05; females: rs?=?0.75, P < 0.001). Von Bertalanffy growth curves well fitted to the relationships between age and SVL and showed a different profile between males (asymptotics size, SVLmax?=?81.9 mm; growth coefficient, k?=?0.63) and females (SVLmax?=?100 mm; k?=?0.40). Results indicate that individuals of L. agilis studied by us are short-living when compared with other populations of the same species.