The Western green lizard (Lacerta bilineata) is a large lizard found in Europe. Its genus name Lacerta and the part of the scientific name bilineata are Latin words which respectively mean “lizard” and “with two lines”; this is reference to the pale lines present on the flanks of the young individuals.
The body of this species is bright green. The head is bigger in males than in females, and the males often show a blue throat. Juveniles are almost brown, with a yellowish belly and two to four pale, longitudinal lines along the flanks. Sub-adults also have these lines, together with several small brown spots on their backs.
Western green lizards are found in Andorra, Croatia, France, Germany, Italy, Monaco, Serbia, Slovenia, Spain, Switzerland, Guernsey, and Jersey in the Channel Isles. They like to live in green humid areas, temperate forests, the edges of woods, shrubland, open grasslands, arable land, and pasturelands.
Western green lizards are diurnal and territorial creatures. They are very good climbers and can often be seen in trees or bushes where they catch their prey. They may also swim. Starting mid-October, Western green lizards hibernate retreat in burrows abandoned by small rodents and hibernate until April.
Western green lizards are carnivores (insectivores). They mainly feed on insects but may also eat fruits, and birds’ eggs.
The breeding season of Western green lizards starts in May/June. Before the mating period, the males fight each other and are very aggressive towards rivals. The mating ritual is precise and starts with a bite to the base of the female's tail. The females lay 6 to 25 eggs in a humid and warm site, such as in a decomposing log and the incubation period typically lasts for 7 to 15 weeks.
The main threats to Western green lizards include the loss of suitable habitat, agricultural practices, and pollution.
The IUCN Red List and other sources don’t provide the number of the Western green lizard total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, but its numbers today are decreasing.