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NEWS RELEASE No: 154735 JUNE 2012

The Snake Pass! Wildlife routes through forests could help rare adder

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Adders in the North York Moors

A new study is helping the Forestry Commission plan a brighter future for the increasingly rare adder in the North York Moors.

The creature is one of the world’s most studied snakes, but mysteries still remain, especially why it is found in some areas, but not others.  Reptile expert James Stroud, 25, pulled on his walking boots and set out to shed light on the subject.

Working with forest rangers he delved into the creature's secret world in Dalby and Langdale Forests, near Pickering, and Harwood Dale, Wykeham and Broxa Forests, near Scarborough. 

Adders are thought to be on the decline due to habitat loss, but the Forestry Commission’s North Yorkshire woods are a stronghold.

As part of his Master’s Degree at the University of Hull’s Scarborough Campus, James probed why the snake preferred some areas over others.  He looked at factors like the availability of food like small mammals and the age of trees.  He also investigated the threat posed by predators like birds of prey and crows by deploying 250 plastercine adders - some of which showed signs of being attacked. 

What he found was that young conifer plantations were adder hotspots and surprisingly the abundance of food seemed less important than the threat from potential foes in determining whether the creature frequented a forest haunt. 

But he also concluded that linking together adder breeding colonies with snake friendly corridors could give the species a big boost.

James Stroud, originally from Amersham, in Buckinghamshire, said:

"Young forest plantations are an important refuge, offering a place to bask and with shelter from potential predators. My data suggests that linking together such areas could be a real help to adder populations.  That would allow them to spread more easily and not become isolated by denser forestry, which is not such a good snake habitat. There is something intriguing and unknown about snakes.  Very encouragingly, I found that there are quite a lot in local forests, but you need to know where to look."

Before stomping through local forests, James did two years of reptile fieldwork in the forests of Sulawesi, Indonesia. He has also worked with the London Zoological Society on breeding programs for endangered reptiles and helped in the first recorded breeding of Komodo dragons through parthenogenesis – a natural phenomenon where eggs are self-fertilised by the female. 

Brian Walker, Wildlife Officer with the Forestry Commission, added.

“James’ work is really important – it reinforces the value of creating wildlife corridors throughout the forest, not just for snakes, but other animals too. Adder colonies are particularly vulnerable to becoming fragmented, which is bad news. They are cold blooded and need to sun bathe to keep up their body temperature. That means they may find it hard to travel long distances under denser forest canopies which block out the sun's warming rays.”

Forestry Commission design plans could be tailored to create adder “corridors” in woods where possible - breeding sites are already plotted on a hi-tech mapping systems. The University of Hull also want to do more research.  Projects could include could DNA testing of adder colonies to discover whether they intermix. Dr Phil Wheeler, Head of the Centre for Environmental and Marine Sciences at the University, supervised James' research. He added:

"James' work has increased our understanding of adders. An important output from his study was a set of reliable methods for studying the snake – there is currently no standard approach and that makes identifying trends in their populations very difficult.  There are many things we still don’t know about this elusive yet utterly fascinating creature.”

Note to editor

The Forestry Commission is the government department responsible in England for protecting, expanding and promoting the sustainable management of woods and forests and increasing their value to society and the environment. Forestry makes a real contribution to sustainable development, providing social and environmental benefits arising from planting and managing attractive, as well as productive, woodlands. More details visit

Media calls to Richard Darn on 0775 367 0038