REPTILES AND AMPHIBIANS

M. Nicholson

Cornwall is home to the four “common” amphibians: Common Frog Rana temporaria, Common Toad Bufo bufo, Smooth Newt Triturus vulgaris and Palmate Newt Triturus helveticus. The two rare British species - the Natterjack Toad Bufo calamita and Great Crested Newt Triturus cristatus - have never (as far as is known) occurred here naturally. The Smooth Newt is something of a rarity in Cornwall, although it is the most common newt in Britain as a whole. It dominates in lowland England in hard water areas, and its natural range extends only slightly into Cornwall with several sightings along the border; records from further west are thought to result from introductions. Translocations of this species are strongly discouraged. By comparison, the Palmate Newt takes over in acidic areas such as Cornwall, western Wales, northern Scotland and the upland areas of England. Of the four native amphibian species found in Cornwall, only one – the Common Toad – is on the UK Biodiversity Plan’s list of priority species.

Cornwall’s pond density is probably lower than that of England, due to differences in geology, land use etc. This imposes an urgent need to protect the remaining breeding ponds. The abundance of amphibians in some areas of Cornwall is linked to the vegetation cover they provide; amphibians spend the majority of their lives on land, often a great distance from their breeding ponds, and moist conditions are essential. The Common Frog seems particularly susceptible to the effects of land drainage.

Until recently, only the four “common” reptiles were found in Cornwall: Adder Vipera berus, Grass Snake Natrix natrix, Common (Viviparous) Lizard Lacerta vivipara and Slow-worm Anguis fragilis. The Sand Lizard Lacerta agilis has now been introduced to a secret location on the north coast of Cornwall. Reptiles require vegetation providing good cover at ground level and easy access to sunlight for basking. Suitable habitats include heathland, unimproved grassland, hedges, verges and dune systems; south-facing hedges and banks are particularly useful. The Adder is frequently associated with heaths and coastal footpaths, while the Common Lizard seems to occupy all of the habitats mentioned. Slow-worms also seem to be common and are perhaps most frequently encountered in gardens. The Grass Snake gives the most cause for concern, as its complex habitat requirements include a combination of dry and wet areas; it is sighted less frequently than the other reptiles and must be considered vulnerable to loss of wetlands.

The UK Biodiversity Action Plan includes a Species Action Plan for the Sand Lizard, while all four “common” reptiles are now included in the list of priority species – the Grass Snake having been added in 2007.

Lacerta agilis Sand Lizard