Mirror Mirror on the Wall, Who's The Rarest of Them All?

Madeleine H
Jun 9, 2020
6 min read

The sand lizard (Lacerta agilis) is the UK’s rarest native lizard species, limited to only a few protected regions. However, reintroduction programmes have been established to help increase the dwindling numbers of this beautiful and vibrant lizard.

Ornate and ready to mate. This male sand lizard shows off his vibrant green colouration. Photo by: Christoph Caina

Distribution

The sand lizard’s range is very restricted to protected heathland regions of Surrey, Dorset, Hampshire, and protected sand dunes in Merseyside. Populations have been reintroduced to protected dune systems in North and West Wales, Kent, West Sussex, Devon and Cornwall to restore its historic range. A sand lizard has a home range of 85-2000m2.

A small population also inhabits the Isle of Coll of the Inner Hebrides in Scotland. A population of 39 sand lizards were reintroduced to the island in the 1970s.

Outside of the UK, the sand lizard can also be found throughout Europe, West Russia, Mongolia and China. Nevertheless, the distribution of the sand lizard is becoming increasingly patchy due to loss of habitat.

Habitat

In the UK, sand lizards inhabit sand dunes and sandy lowland heathland. Although commonly thought as a sandy heathland specialist, the sand lizard demonstrates a high degree of adaptability. In heathland habitats, the sand lizard can be found living amongst unshaded interspersed heather on south facing slopes, with open bare ground in which they lay their eggs. Sand lizards also inhabit sand dunes with mature marram grass, which provide suitable prey, warmth, and protection from predators.

Sand lizards inhabiting the frontal sand dune systems of the Sefton Coast, Lancashire, coexist alongside the rare British toad species, the natterjack toad.

A female sand lizard with beautiful ocelli. Photo by: Pete Hill

Another handsome male shows off his vivid green colouration to attact a mate. Photo by: George Chernilevsky

Identification

Sand lizards are short legged and stocky, growing to 20cm in length. Colouration varies between individuals, but most commonly sand lizards are shades of grey and brown. Sand lizards can typically be identified by two pale lines along their backs, with black, dark brown or light tan mottled markings between these lines. Ocelli (white spots or short stripes) form an unbroken line down the spine. It is not uncommon for there to be up to 3 white ocelli down the spine.

During mating season (mid-April to mid-May) male sand lizards develop vivid green flanks. The males are easily identifiable during this period by their bright green colouration and mottled brown backs. Male sand lizards can retain some green colouration outside of breeding season, although it is not as pigmented. Flank mottling seen in male sand lizards is finer, black and more crowded than that of females, which are browner in colour and have regular, larger ocelli along their flanks. Males can further be distinguished from females by their stockier appearance, heavy set jaws and larger heads. The eyes of female sand lizards are situated half way along the head, whilst the eyes of male sand lizards are placed one third along the head, closer to the neck. Melanistic (black) and albino individuals do exist but are extremely rare.

The sand lizard can be confused with the common lizard (Zootoca vivipara), another native lizard species in the UK. Greener colourations of the common lizard most frequently mistaken for sand lizards. Sand lizards can be distinguished from common lizards as there is almost never a broken dark line down the spine, like that seen in common lizard markings. In the South of England, two introduced lizards, the common wall lizard (Podarcis muralis) and western green lizard (Lacerta bilineata), can also be confused for the sand lizard.

A male and female sand lizard on a romantic date to the sunny log. Photo by: David Courtenay

Diet

Sand lizards are opportunistic feeders, mostly consuming invertebrates, like for spiders, grasshoppers and crickets. However, male sand lizards are known to eat juvenile sand lizards and juvenile common lizards. Sand lizards are an ambush predator and forager. Sand lizards hunt by moving several meters, pausing, and flicking their tongue to detect prey. They have also been known to feed on fruits, and flower heads.

The sand lizard is naturally predated on by foxes, badgers, birds and snakes, as well as domestic animals, such as cats and chickens.

Hibernation

Sand lizards hibernate in burrows, dug into sandy ground. Males hibernate from late August/early September to April/May. Females go into hibernation later, hibernating from September/early October to April/May. Juveniles typically hibernate later than adults, in late October, as this allows them to consume enough food to survive the winter.

Burrows

Sand lizards dig burrows into sandy soil, which are used as refuge sites and for hibernation. Burrows are typically 5cm in diameter and 1m deep. Burrow entrances are concealed by undergrowth. The burrows are dug into a slope and feature a sharp bend after a couple inches to keep the lizard hidden. Moreover, the burrows have an upwards profile, which assists with drainage. Sand lizards are even known to burrow into the walls of rabbit warrens.

There's no place like home. A sand lizard in its burrow. Photo by: Danielle Sweet

Another devilishly handsome male sand lizard with a flower. Photo by: Silviu Petrovan

Reproduction

During breeding season, male sand lizards become territorial and aggressive, and will fight rival males. Courtship begins once the female chooses a suitable mate. During a courtship ritual, the pair will circle each other. The female will then lie flat on the ground, with her hind legs facing towards the sky. She will then wiggle her legs as a sign of acceptance. The male will then grab the female at the base of her tail or around her middle. Sometimes males will be more aggressive, holding females in his jaws and forcing coitus.

Reproduction lasts from a few seconds to several minutes. After reproduction, females will leave and males will stay to defend their territory and patrol for a new mate. Occasionally, males will stay with the female to protect her from rival males.

At the end of May and early June, females will dig a series of burrows and test their suitability for egg-laying sites. Between 2 to 16 (typically 8) egg are laid in the final burrow. The eggs hatch 8 to 10 weeks later. Gravid females are more vulnerable to predation when digging nests. Additionally, there is high competition for the best nesting sites, with dominant females stealing nests of subordinate females. Populations in the South of England have been known to produce two clutches, with the second clutch laid in late summer. As global temperatures rise, this is likely to become more common across sand lizard populations.

Juveniles hatch at the end of August and are left to fend for themselves. Juveniles will spend the first few months of their life living in groups of twos and threes, and hunting together. Juveniles can be identified by the two light dorsal stripes and rows of ocelli along their flanks. Juvenile sand lizards can be easily confused with juvenile common lizards; however, juvenile common lizards are almost black when young, whilst juvenile sand lizards have rows of ocelli. Sand lizards reach sexual maturity at three to seven years old.

Ooddles and ooddles of juveniles. Photo by: Mike Berwick

The Greatest Threat to Sand Lizards

Despite ranked as Least Concern on the IUCN Red List of Endangered Species, the sand lizard is becoming increasingly rare in the UK. The biggest threats to sand lizard populations are habitat loss, mismanagement, fragmentation and degradation. 90% of sand lizard habitat has been lost over the past century. Afforestation of heathland, agricultural reclamation, military activity and mining have further contributed to sand lizard declines. Sand lizard populations are fragmented and isolated.

In Merseyside, 50% of sand dune systems were lost between 1801 and the 1970s. Populations in Dorset, Weald and Merseyside have declined by 90%, 95% and 97% respectively, since the 20th century.

Conservation and Legislation

The sand lizard is protected in the UK by the Wildlife and Countryside Act (1981), and is listed as a priority species on the UK Post-2010 Biodiversity Framework. The sand lizard is further protected as a European Protected Species under Annex IV of the European Habitats Directive. These legislative acts make it an offence to kill, injure, capture, or disturb them. Moreover, it is illegal to damage or destroy sand lizard habitat, and possess or trade them.

The Wildlife Trusts are working towards restoring and protecting heathland and coastal sand dune systems, through the promotion of sustainable land management, clearing encroaching scrub, and implementing beneficial grazing regimes. The Wildlife Trusts have also been involved in reintroduction projects of sand lizards into their historic range.

The Amphibian and Reptile Conservation Trust are also working on the restoration and expansion of sand lizard habitat, as well as providing open sand for nesting sites and basking sites. The ARC Trust also work towards the monitoring the status of sand lizards through field surveys and habitats assessments, and reintroduction programmes of captive bred hatchlings. Reintroductions have been successful at re-establishing sand lizard range. The ARC Trust also undertake advocacy work to encourage policies and sustainable actions that benefit sand lizards, and run projects for sand lizard conservation, such as the Gems in the Dunes on the Sefton Coast.

How to Help

Sand lizards are not typical garden species. However you can help sand lizards by volunteering at your local wildlife trust, or donating to the ARC Trusts sand lizard projects.

You can sponser a sand lizard here: https://www.arc-trust.org/donate/sponsor-sand-lizards/5/credit-card