Western green lizard (Lacerta bilineata)
|Size||Snout-vent length: c. 13 cm (2)|
Total length: up to 40 cm (3)
- After many unsuccessful introduction attempts, the western green lizard now has a self-sustaining population in the United Kingdom.
- A highly variable species, the western green lizard may be green or brown and have many different patterns on its skin.
- The throat of the male western green lizard is blue, although this colouration also sometimes occurs in females.
- The female western green lizard reaches sexual maturity when it has a snout-vent length of around eight centimetres.
The western green lizard is classified as Least Concern (LC) on the IUCN Red List (1).
The western green lizard (Lacerta bilineata) is a large, elegant lizard with a highly variable appearance. The male is typically green with black speckling along its back, and its short, deep head is dark and patterned with light spots. The throat of the male is blue, although some females also share this distinctive feature. The female may be green or brown and occasionally has blotches on its skin. The female western green lizard may also have two or four narrow lines running along the sides of its body, which can occasionally be bordered by black spots or have black edges (2).
The western green lizard hatchling is initially brown, gradually developing its adult colouration. The extent of black colouration on the back increases as the individual ages (3). The hatchlings may have a few light spots or lines along the sides of the body, but may also be a uniform colour (2).
The range of the western green lizard spans much of western and central Europe, including Spain, France, Italy, Switzerland, Andorra, Austria, Croatia, Monaco, Slovenia, the Channel Islands and Jersey (1). This species also has small, isolated populations in southwest Germany and has been introduced to the United States and the United Kingdom (1) (3). The deliberate introduction of this species to the United Kingdom has resulted in a self-sustaining population in Bournemouth, which is thought to be growing and spreading along the coastline into other areas (3).
The western green lizard is found among dense vegetation in damp areas where there is good exposure to sunlight (1) (2). It inhabits open woodlands, scrubland, grasslands, dunes and coastal heaths (1) (2) (3), as well as woodland edges and along fences surrounding cultivated land (1). This lizard can be found up to elevations of 2,200 metres (2).
The breeding season of the western green lizard begins in late May (3), when the female lays a clutch of between 6 and 23 eggs in loose sand or vegetation (2) (3). The eggs hatch in August or September (3), around 7 to 15 weeks after being laid (2). The female western green lizard reaches sexual maturity when it has a snout-vent length of around eight centimetres (2).
The diet of the western green lizard is mainly composed of arthropods and other invertebrates (2) (4), although this species is also known to take fruit and bird eggs and nestlings (2).
One of the main threats to the western green lizard is habitat loss, and there have been significant population declines in areas where there is intensive agricultural activity. This species is also threatened by other human activities such as burning of scrubland and pesticide use (1). In certain areas, this species is predated by domestic cats and dogs (3).
The range of the western green lizard is increasing in some areas, which may pose multiple threats to native species, including competition for food and nesting sites, and predation of their juveniles. This species may also be a vector of disease, which could be spread to native species (3).
The western green lizard is listed on Appendix III of the Bern Convention (5) and Annex IV of the EU Habitats Directive (6), both of which provide guidelines for the conservation of European flora and fauna (1). This species is found in many protected areas and has legal protection throughout its native range (1).
Further research and monitoring of the western green lizard has been recommended to secure its future survival. Less intensive forms of agriculture must also be developed to reduce future damage to this species’ habitat (7).
Learn more about reptile conservation:
International Reptile Conservation Foundation:
Find out more about the western green lizard as an invasive species:
GB Non-native Species Secretariat (NNSS): Factsheet - Western green lizard:
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- Arthropods: a major grouping of animals that includes crustaceans, insects and arachnids. All arthropods have paired jointed limbs and a hard external skeleton (exoskeleton).
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.
- Snout-vent length: a standard measurement of body length for reptiles and amphibians. The measurement is taken from the tip of the snout to the vent (cloacal opening), and excludes the tail.
IUCN Red List (October, 2013)
- Arnold, N. and Ovenden, D. (2002) A Field Guide to the Reptiles and Amphibians of Britain and Europe. Collins, London.
GB Non-native Species Secretariat (NNSS): Factsheet - Western green lizard (October, 2013)
Angelici, F.M., Luiselli, L. and Rugiero, L. (1997) Food habits of the green lizard, Lacerta bilineata, in central Italy and a reliability test of faecal pellet analysis. Italian Journal of Zoology, 64(3): 267-272. Available at:
Council of Europe: Bern Convention (October, 2013)
EU Habitats Directive (October, 2013)
Elbing, K., Nettmann, H.-K. and Rysema, S. (1997) Green Lizards in Central Europe: Status, Threats and Research Necessary for Conservation. Herpetologia Bonnensis: Proceedings of the 8th Ordinary General Meeting of the Societas Europaea Herpetologica, 23-27 August 1995, Bonn, Germany. Available at: