Why captive breed sand lizards?
The biology and status of sand lizards mean that captive breeding is a useful conservation tool. In the wild, the vagaries of our climate, predation and disturbance to egg-laying areas mean that only around 5% will survive to become adults. Since sand lizards cannot disperse far, or indeed at all over hostile habitats, they won’t colonise newly suitable areas. All of this means that to recover their lost range, we need to breed and release sand lizards.
The captive breeding programme gathers a range of organisations including ARC, government agencies, volunteers, Marwell Wildlife, Chester Zoo and the Institute of Zoology. Together we have have developed best practice for both husbandry and re-introduction. Animals are kept in specially designed enclosures at 10 facilities, in as natural conditions as possible.
Supplementary feeding and controlled egg incubation are required to ensure high success rates of healthy newborn lizards. As these hatch much earlier than animals in the wild, they also mature earlier and show much higher survival rates when they are released in the wild.
The reintroduction programme has undertaken 76 re-introductions to both dune and heathland sites in England and Wales (as of 2012). This has been undertaken to 11 counties, and restored the species to 7 counties where sand lizards had gone extinct. As a conservative estimate, this represents a 65% success rate (where a population has been reliably established), 12% initial success (further monitoring needed), 15% are currently ongoing, 4% failed (largely due to inadequate habitat management) and 4% unknown (often due to difficulties over access at sensitive sites). To date around 9000 animals have been released through the programme.
There are three 'races' of sand lizard in the UK (Dorset, Wealden and Merseyside) and all are represented in the reintroduction programme. Several new populations of the Dorset race have been introduced, helping to secure and expand its core range. The Wealden race is now restored to much of its former range. Since 1995 there have been releases of the Merseyside race, including extremely successful reintroductions into North Wales after an absence of more than 50 years.
Further new sites for all three races have been identified and the releases continue. The releases also offer a superb educational opportunity, giving local volunteers, enthusiasts and school groups the chance to see such a rare lizard. The associated media coverage also helps raise public awareness, not just about these beautiful animals and their plight, but about reptile and amphibian conservation as a whole. For an example, see this coverage of a release in Surrey: Sand lizards returned to Farnham Heath; BBC News website; 15 September 2012.
All of this represents a fantastic outcome for sand lizards, and compares favourably with other reintroduction programmes. You can read more detail on the sand lizard programme in a chapter by ARC’s Nick Moulton in the IUCN publication “Global Reintroduction Perspectives: 2011” [Full reference: Soorae, P. S. (ed.) (2011). Global Re-introduction Perspectives: 2011. More case studies from around the globe. Gland, Switzerland: IUCN/SSC Re-introduction Specialist Group and Abu Dhabi, UAE: Environment Agency-Abu Dhabi. xiv + 250 pp.]