Hinneberg, H., E.-M. Riedel, K. Foerster & A. Kupfer

Interrelation of colouration and morphological traits in Northern Crested Newts (Triturus cristatus): towards a non-invasive tool for age determination. pp. 57-65

Abstract. Determining animals’ age is important for a wide range of study fields in biology. However, age determination is often problematic because it relies on invasive techniques. For the Northern Crested Newt (Triturus cristatus) various morphological traits are believed to be age-related. Quantifying interrelations among four morphological characteristics (snout–vent length, crest morphology, ventral colouration, tail base spot size), our study demonstrated that the traits are interrelated within and across populations. Both genetic and plastic adaptation to local environmental conditions unlikely explain the observed trait correlations. Furthermore, we found significant differences in snout–vent length and ventral colouration between adult and juvenile/subadult Crested Newts. Thus, there is strong evidence that the studied traits are age-related. Even though the ontogenetically mediated trait variation is masked by a non-age-related variability, the analysis of morphological traits serves as a powerful tool for obtaining insights into Crested Newts’ population demography in a non-invasive fashion.

Key words. Amphibia, Caudata, population demography, monitoring, snout–vent length, crest morphology, belly pattern, tail base spot size.