The composition of the fauna of Lesvos depends on ecological, geographical and historical factors, but also on the influence of man, which in the Aegean region is very long and intense. Thus, the fauna of the island is as rich as the flora, including species from the East and the West.
Of the mammals, the presence of the ‘’Galia’’ stands out, as the inhabitants of the island call the Persian squirrel (Sciurus anomalus), for which Lesvos is the westernmost limit of distribution. Other mammals of the island are the fox (Vulpes vulpes), the marten (Martes foina), the weasel (Mustela nivalis), the hedgehog (Erinaceus concolor), the hare (Lepus europaeus), while in some wetlands of the island they may still live otters.
Five species of amphibians are found on Lesvos: the most common species are the green toad (Bufo viridis) and the green frog (Rana ridibunda). The brown toad (Bufo bufo) is rare, while the presence of the Pelobates (Pelobates syriacus), a species with small numbers in Greece, is worth noting.
The herpetofauna is particularly rich with species such as terrapins, loggerhead turtles, tylipites, crocodilians, samiamiids, kurtodactyls, tranosaurs, ophisopes, avlepharus, herringbones, typhlines, vipers, bush snakes, sapites, water snakes, lake snakes, shuttlecocks, hornbills da, house snakes and ottomans vipers. 11 of the 13 reptile families of Greece are represented here. A total of 21 reptile species, 3 turtle species, 7 lizard species and 11 snake species have been recorded.
Birds are a very important, and certainly the most popular, chapter of the biodiversity of Lesvos. The wetlands and other habitats of the island are living, feeding, nesting and breeding areas for more than 300 species of European, Asian and African avifauna.
Occasionally, European birds appear, which, while they do not carry out the typical migration to other continents, resort to the wetlands of Lesvos to hibernate in particularly severe winters. So it is no coincidence that in recent years Lesvos has emerged as one of the most popular destinations for bird watching in the Mediterranean.
In Lesbos you can see bird species from Europe, Asia and Africa. Some species, such as Pefkotsopanakos and Smyrnosichlonos, have the western limits of their global distribution in Asia Minor and only on the island of Lesvos from the European area. . The Pefkotsopanakos is a rare species and is found mainly in the pine forests, from the sea to its highest peaks, in the area of Olympos, Achladeri, Akrasi. The Smyrna gum is rarer and can be seen in Eressos, the Petrified Forest, Mount Olympus, Agra.
Other important species are: the Black Stork (Ciconia nigra) with a few pairs on the island. They nest in the pine forests in the area of Akrasi, Achladeri and the Potamia valley. In Lesvos there are also White Storks (Ciconia ciconia) which have been on the decline in recent years.