About Hyla arborea (Linnaeus, 1758)
European tree frogs (scientific name Hyla arborea (Linnaeus, 1758)) are small, slender amphibians with long legs. Males measure 32–43 mm (1.3–1.7 in) in length, while females are larger at 40–50 mm (1.6–2.0 in). Their dorsal skin is smooth, and their ventral skin is granular. Dorsal skin color can change to green, gray, or tan based on environmental temperature, humidity, or the frog’s mood. Ventral skin is whitish, and a dark brown lateral stripe runs from the eyes to the groin, separating the dorsal and ventral color regions. Females have white throats; males have golden brown throats with large folded vocal sacs. This species has a rounded head, a sharply sloping lip, a horizontally elliptical pupil, and a clearly visible tympanum. A key characteristic feature of Hyla arborea is the adhesive toe discs that allow it to climb trees and hedges. Like all frogs, its hind legs are much larger and stronger than its fore legs, enabling rapid jumping. Members of the H. arborea species complex are the only native representatives of the widespread tree frog family Hylidae found in mainland Europe. This complex occurs across most of Europe (excluding the United Kingdom), northwest Africa, and temperate Asia extending east to Japan. It is native to Albania, Armenia, Austria, Azerbaijan, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, France, Georgia, Germany, Greece, Hungary, Jordan, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Moldova, Montenegro, the Netherlands, North Macedonia, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Turkey, and Ukraine. In the United Kingdom, this species is legally classified as non-native; it was introduced to the region and is currently thought to be extinct there. European tree frogs inhabit marshlands, damp meadows, reed beds, parks, gardens, vineyards, orchards, stream banks, lake shores, and both humid and dry forests. They avoid dark, dense forests, can tolerate short dry periods, and may sometimes be found in dry habitats. European tree frogs reproduce in stagnant water bodies including lakes, ponds, swamps, reservoirs, and occasionally puddles, with breeding occurring from late March to June. Males croak during the breeding season, even while migrating to mating ponds. Males often switch breeding ponds within a single breeding season. After a spring rain, males call to attract females from low vegetation or shallow ponds. Females lay 800 to 1000 eggs in clumps roughly the size of a walnut; individual eggs measure about 1.5 mm in diameter. Eggs hatch 10–14 days after laying, and tadpoles complete metamorphosis into adult frogs after three months. Peak metamorphosis typically occurs from late July to early August. This species can live up to 15 years.
