Variability in the dorsal pattern of the Sardinian grass snake (Natrix natrix cetti) with notes on its ecology

The Sardinian grass snake (Natrix natrix cetti) is a Critically Endangered snake endemic to Sardinia (Italy), for which information is still scarce. In the present work, we report information obtained from 36 observations of N. n. cetti performed in different areas of the Island. Three different colorations were mainly observed and darker snakes were in general males and big adults; the only juvenile found showed a complete different dorsal colouration. Snakes were observed active during day-time and often far from the aquatic habitats.