Image courtesy of Wikimedia commons
It may surprise some people to learn that the UK has 3 native lizard species. These are the common lizard, the slow worm – a legless lizard resembling a snake, and the sand lizard. The last of these three species is extremely rare due to habitat loss among other threats.
The biology of sand lizards is well known, which allows captive breeding to be an effective conservation tool for some time now in order to help headstart juveniles and to reintroduce the lizards to sites they once occupied. In general this has been very successful although sand lizards are not out of the woods yet.
Sand lizards are the UK’s largest native species of lizard and one of our rarest reptiles. They rely on sandy heathland habitats, where they lay their eggs. Males emerge from hibernation in the spring and transform into a vivid green colour as they get ready to mate. This green colouration is a signal to the females that the male is in top condition and an excellent partner with which to reproduce. Once they’ve mated, females lay their eggs in sandy burrows around June or July leaving them to incubate, with the young hatching a couple of months later. The sand lizard is unique among our native lizards as they lay eggs, our other two species give birth to live young.
Due to the unpredictability of British weather, on average only 5% of hatchlings will make it to adulthood in the wild. A team of partners including the Amphibian and Reptile Conservation Trust and Chester Zoo are working around the clock to breed and rear sand lizards ready for release back into the wild. There are currently 10 specially designed facilities with conditions mimicking the natural world as closely as possible.
In order to ensure a higher success rate than in the wild, eggs are incubated artificially and hatchlings are given supplements in order to ensure they grow big and strong. These animals usually hatch much earlier than wild animals and therefore mature sooner, also showing higher survival rates when they are released into the wild. To date over 9,000 animals have been released through the program with a 65% success rate of establishing a colony. There is certainly more to be done but the future for these charismatic little dragons is slowly getting brighter.
Around the UK, there are three 'races' of sand lizards that can be found in Dorset, Wealden and Merseyside. Each race is represented in the reintroduction programme and can be differentiated from one another using a small number of clues, such as the vibrancy of the male’s green colouration. Only local individuals from each of these races are released into their corresponding areas to ensure the purity of the races. This has raised some eyebrows about the possibility of inbreeding, but further research is still needed.
Reintroductions also help to secure the range of sand lizards as well as expanding it, as they have a very poor dispersal ability. Every helping hand they get is another step towards securing their future. The Wealden race has now been restored to much of its former range and the Dorset population isn’t far behind. Since the mid-90s attention has also focused on the Merseyside race. This includes a number of successful reintroductions into North Wales where the lizards had been absent for more than 50 years. As the project continues to grow, new sites for all three races have been identified with the releases planned for the future.
Public engagement is a huge part of the project’s success, offering an educational opportunity to local school groups, volunteers, and enthusiasts. This also has the added bonus of raising awareness in the public eye. Despite the fact the lizards are currently strictly protected by both EU and UK law, they are still accessible to people – helping them reconnect with nature by seeing such a rare species.