Grass frogs live in various different habitats: woods, meadows and alpine pastures up to the snow limit.
In spring the wetlands of the National Park resound to the croaking of grass frogs. These frogs occur in meadows and woodland up to an altitude of 2500m. Mainly nocturnal, they can sometimes be seen during the day.
The colouring of the grass frog is very varied, from grey or brown to reddish brown or olive. Typical are the dark spots on its back and its white or yellowish underparts.
In April and May the female lays her eggs in permanent water holes and bogs.
Up to 3000 eggs can be present in these large spawn masses, of which only a very small fraction survive and become adults. Birds in particular are very fond of this delicacy!