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Western Green Lizard (Lacerta Bilineata): Description Of The Species

Western Green Lizard | Lacerta Bilineata | Adult Male During Mating Season | Spring 2021



The western green lizard belongs to the family of the Lacertidae (Wikipedia link for Lacertidae : It; Fr; En; De). This is the family of the wall lizards and true lizards, which are native to Europe, Africa, and Asia. The group includes the genus Lacerta, which contains some of the most commonly seen lizard species in Europe. It is a diverse family with at least 300 species in 39 genera.

Interestingly, the Wikipedia articles in 4 different languages I consulted for this page differ in some small details and also in the amount of information they offer (the most informative article about this particular lizard is the one in German for those who are interested). An example for some of the differing details would be how the articles don't quite seem to agree on the size/length of the animal: English and German Wiki  state that the lizards reach a length of up to 40 cm, while French Wiki only speaks of an average size of 30 cm, and Italian Wiki claims the species reaches up to 45 cm.


From my personal observations I definitely agree with Italian Wiki as I estimated the size of the largest males I encountered in the Malcantone region of Ticino (Switzerland) - which is where I took all the photos on this site - at more then 40 cm. It would appear logical though that there are regional differences in the size of the species. Anyway, in such cases where the  information slightly varies across the different articles, I went with a good old compromise (which means here you'll read that the species Lacerta bilineata typically reaches a size of between 30-45 cm).


For the original Wikipedia pages, just click on the links here: Italiano; Français; EnglishDeutsch.


The genus name Lacerta and the species name bilineata are Latin words respectively meaning “lizard” and “with two lines”, with reference to the pale lines present on the flanks of the young individuals.

Western Green Lizard | Lacerta Bilineata | Adult Male In Honeysuckle Bush | Spring 2021
Western Green Lizard | Lacerta Bilineata | Adult Female On Branch | May 2021
Distribution of Lacerta bilineata (green) and Lacerta viridis (blue)



The map shows the distribution range for Lacerta bilineata (green) and Lacerta. viridis (blue) and the small area (yellow) where a degree of hybridization between the two species occurs (link for the map: Wikipedia). Lacerta viridis - the European green lizard - is the closest relative of the western green lizard. The two species are not easily distinguished without genetic analysis and get often confused; in fact, they were only recognized as different species as recently as 1991.

Lacerta bilineata is native in Andorra, Croatia, France, Germany, Italy, Monaco, Serbia, Slowenia, Spain, and Switzerland. It was introduced in Guernsey and Jersey in the Channel Isles and the United States, and there are also introduced colonies on the south coast of the U.K, notably around Poole Bay in Dorset.




Western green lizards are among the largest lizard species in Europe; adults reach a length of 30 to 45 centimeters including tail (there may be regional differences regarding the size of the species). The tail may reach up to twice the body length. The average weight is about 35 grams. Males are generally a bit bigger than females, with a slightly bulkier head and body.


With females of the species colors and color patterns can vary greatly and range from dark green and brown to shining emerald green, turquoise and blue and everything in between, even colors that are more typical for males.

Adult males tend to look more alike (though there are variations too), with their back usually a striking yellowish to emerald green interspersed with black dots, a yellow or yellow-green belly and blue face, all of which much more pronounced during mating season (the adult male lizards in the gallery below were all photographed during mating season in May, when their colors were particularly intense, except for the last 4 photos, which were taken in August and September).

As juveniles the lizards are mostly brown with a yellowish green chest and belly. Within a year, as adolescents and sub-adults, they develop white lines or dots on both flanks often in combination with black spots until their eventual color patterns start to shine through (as already mentioned above, those two white lines are also responsible for the species' Latin name "bilineata" which means "two-lined") .