The Sand Lizard, Lacerta agilis, is a reptile inhabiting various regions across Europe and parts of Asia. It possesses distinct features and behaviors. Understanding its life provides insight into the diverse ecosystems it calls home.
Physical Characteristics and Identification
The Sand Lizard is a medium-sized reptile, typically reaching 16 to 20 centimeters, though some can grow up to 25 centimeters. Both males and females display lateral and dorsal strips of ocellated (eye-shaped) markings, appearing as dark patches with pale centers. Many individuals also feature two thick, light-brown dorsal stripes running parallel down their backs.
Sexual dimorphism is notable, particularly during the breeding season. Males develop vivid grass-green flanks that intensify in color, while females are generally more subdued grey to brown with more pronounced markings. This green coloration in males serves as a clear identifier, distinguishing them from other lizard species. Sand Lizards are also larger and more robust than the Common Lizard, with proportionally larger heads.
Habitat and Geographic Distribution
The Sand Lizard occupies a broad geographic range spanning much of Europe, from Britain eastward to Lake Baikal in Russia, and extending into parts of Asia, including Mongolia and northwest China. Its distribution across this vast area is often patchy, reflecting its specific habitat requirements.
These lizards prefer open, sandy environments such as heathlands, coastal sand dunes, grasslands, steppes, and the edges of woodlands. They thrive in areas with varied topography, offering multiple basking spots and mixed vegetation for cover and prey. Open, south-facing sandy patches are particularly important for egg-laying, as the warmth of the sand is needed for incubation.
Behavior and Diet
Sand Lizards are diurnal, active during the day, often basking in sunny spots to warm their bodies. They retreat to burrows in the sand for overnight rest and hibernation during the colder winter months. In the spring, males typically emerge from hibernation before the females, preparing for the breeding season.
The species is a generalist carnivore, its diet consisting primarily of insects and other small invertebrates. They employ a pause-travel foraging strategy, alternating short bursts of movement with stillness while hunting. Common prey items include spiders, grasshoppers, crickets, adult flies, beetles, and larval butterflies, though ants are generally avoided.
Reproduction and Life Cycle
The reproductive cycle begins as Sand Lizards emerge from hibernation in March or April, with mating typically occurring from April to June. During this period, males display their bright green flanks and may exhibit aggressive, territorial behaviors towards other males, sometimes guarding females.
As an oviparous species, females lay eggs, usually a single clutch of 6 to 12 eggs, though a second clutch can be laid in warm summers. Eggs are deposited in self-dug burrows, about 7.5 centimeters deep, in loose, sun-exposed sandy patches between late May and early July. The female carefully selects these sites, assessing temperature, humidity, and texture. After laying, she provides no parental care. The eggs incubate for about one to two months, hatching primarily in August and September. Hatchlings emerge at about 5 centimeters in length, resembling the adult coloration and markings. Sand Lizards typically reach sexual maturity around three years of age and can live for 10 to 12 years in the wild, with some females potentially reaching 18 years.
Conservation Status
Globally, the Sand Lizard is categorized as “Least Concern” by the IUCN, reflecting its widespread distribution. However, populations in the northwestern parts of its range, including the United Kingdom, Scandinavia, and northern Germany, have experienced declines and are considered threatened.
The species receives protection under Appendix II of the Bern Convention and Annex IV of the EU Habitats Directive (92/43/EEC), which ensures strict protection of individuals and their habitats within European Union member states. Threats to the Sand Lizard include habitat loss, degradation, and fragmentation, often resulting from agricultural expansion, forestry practices, urban development, and the encroachment of scrubland. Conservation efforts, such as reintroduction programs and habitat restoration projects, are underway in several affected areas to stabilize and increase populations.