On the sunny Sunday morning of 10 April, fourteen of us met Neil Clennell, Chief Executive of the Wychwood Forest Trust and herpetologist, near Greenham Common to look for reptiles. Neil was absolutely confident – and rightly so – that we would easily find adders.
We joined Neil in what is now a business park but which was formerly part of the RAF, and later, United States Air Force base, infamous for the ground launched cruise missiles. The base was closed in 1992 and the airfield dismantled; it is now an SSSI, open to the public for recreational activities. The southern edge is not an SSSI, and consists largely of concrete rubble left over from the clearance of the air base. A perfect habitat for adders and other reptiles!
The Greenham Common site is apparently one of the best in England for finding adders. They have become increasingly scarce throughout the country due to habitat disruption, over-assiduous land management and the introduction of pheasants who will peck snakes and possibly kill their young. Disruption of adder habitat can be catastrophic, particularly if summer feeding grounds are separated from hibernation sites (hibernacula) through road building or housing. Although protected under the Wildlife and Countryside Act, adders and other reptiles are still very much affected by such disruption.
Much research has been undertaken to try to discover genetic links in adders from different sites in England. It would appear that there are similarities between those in the south of England but those similarities disappear the further north one goes. Different methods have been used to collect DNA. The current method is to collect it from the cloaca with a cotton wool bud. Further research uses minute radio tracking devices, taped to the snake, which eventually fall off when the snake sheds its skin.
Adders are cold tolerant and are the only snakes found in the Arctic circle. Even so, they appreciate warmth and the Greenham site is ideal for them as the waste concrete warms up quickly and allows for basking while at the same time offering plenty of cover.
Hibernation occurs from around October to March. After about three weeks of warm weather the males become more active and start competing with each other for females, wrestling rather than biting as the venom would be fatal.
Females give birth around two months after mating. Adders are viviparous, giving birth to live young which have developed inside the body of the parent. Some females may only breed once in a lifetime, depending on the habitat and access to food.
As we walked around the site, Neil was able to point out several adders, warming themselves on the concrete. The sexes are different: the males having paler background colouring and stronger patterning whereas females tend to be browner with less distinct markings. There is a theory that the predominant black markings along the head and back may be an evolutionary advantage as the black attracts warmth from the sun and hence warms the spinal column.
Wearing a thick leather glove, and with the help of a stick with a hook at the end, Neil managed to pick up one of the males so that we could have a closer look. Quite lively at first, it soon calmed down but would raise its head and flick its tongue at us. Nobody wanted to stroke it.
On our return to the car park, Neil showed us a slow-worm, which he found under a metal sheet.
Other wildlife noted were brimstone butterflies, four bumble bee species, a bee-fly, chiffchaffs and a blackcap were heard.
Everyone enjoyed a really interesting few hours with Neil who was thanked for his time and expertise. The warm sunshine made our visit particularly enjoyable too!
Julia Reid, 11 April 2022
A young visitor who was with us that day really enjoyed himself and has sent in his own report and picture.
Will Southcott (age 9) writes:
I saw ten or over adders here is a picture of an adder.
I also found 2 Adder skins and female Adder’s have darker skin than male Adders. And I saw a slow worm which is actually a legless lizard.