The alpine newt (Ichthyosaura alpestris) can be recognized by its orange belly which lacks pattern. During the mating season (spring - aquatic phase) males have a bright blue base color, often display black spots on the sides and have low, smooth dorsal crest which has a black-white pattern. Females are usually blue-grayish to grey-green colored with a marbled pattern.
After and before the mating season the animals adopt a terrestrial lifestyle. Both sexes are darker in color, the skin is more grainy in texture and in males the dorsal crest is reduced. Alpine newts can attain lengths of 12 cm on average. The larvae have a relatively dark base color and have a stumped tail.
distribution and Life History
Alpine newts occur in the south and east of the Netherlands, often near forests, small pockets of forests and hedgerows. Loamy soils are preferred especially wooded areas or small (agricultural) landscape with ample hedges and wooded areas. In several locations in the east and center of the country the species is introduced.
The species demands fairly little of its breeding waters. Fast flowing waters and waters with a lot of fish are avoided. Alpine newts hibernate on land (there are a few records of animals hibernating in water). In February, depending on prevailing weather conditions, the animals migrate to their breeding waters.
From April until the end of May the animals court and mate. Females deposit their eggs one at the time by means of folding an egg in a leave of vegetation (water plants). If vegetation is absent as is often the case in shaded ponds, females lay their eggs in dead leaves the the bottom of the pond. The eggs of alpine newts are grayish which is especially noticeable in freshly deposited eggs.