13 December 2010
The adder is one of three snake species native to England. Adult adders typically reach a length of around 55cm (2ft), and have a distinctive dark zig-zag pattern down the back. Males tend to have black markings on a grey background, while females have dark brown markings on a reddish-brown background. The adder is found in most counties, but is patchily distributed. It occurs most frequently on free-draining soils in areas open to plenty of sunshine, mostly on heathland, moorland and open woodland. In recent decades, adder populations have declined in many areas. For example, adders are now considered extinct in Hertfordshire, and very rare in Nottinghamshire. Factors such as habitat loss and fragmentation as well as persecution are important. Thankfully, robust populations still exist in counties with large tracts of good habitat, such as North Yorkshire.
Latin name: Vipera berus
Precise national figures unknown, but broad distribution is well understood. Of most concern are the declines observed at many sites in the Midlands.
Where to see and when:
Adders can often been seen basking at the edges of tracks from March to October. Good places include large areas of open heathland and moorland, such as Thursley National Nature Reserve (Surrey) and the North York Moors.
What’s being done:
Many organisations manage land to help adders, yet some site managers have requested further guidance. As a consequence, Amphibian and Reptile Conservation (ARC) and Natural England have written a detailed guide, the Reptile Habitat Management Handbook, published in October 2010. Surveys for adders, to track how known populations are faring and to discover new ones, are done by many volunteers, particularly the Amphibian and Reptile Groups – UK network. There has been concern that some adder populations are becoming small and isolated, and so may suffer from genetic impoverishment. To address this, a project will assess the genetic status of adders in 2011. This is a joint project between the University of Oxford, the Institute of Zoology, Natural England and ARC.