Three species live in Slovenia, which we group in the subgenus of green frogs (Pelophylax). These are the painted frog (Pelophylax lessonae), the thick-headed frog (Pelophylax ridibunda) and the green frog (Pelophylax kl. esculenta). All three species are fairly similar to one another, and at the same time different individuals of the same species can look very different. Therefore all three species of green frogs, which also live in the Notranjski Park area, are treated together.
Green frogs are usually light green in color, but the coloration of their bodies is quite variable, and we often also observe completely brown individuals as well as all possible color transitions. A common feature of male green frogs are the external vocal sacs, which amplify the sound during croaking. In addition, there are, in broad bands arranged, the rows of dorsal glands at the transition from the hips to the back in all green frogs just in front of the hind limbs, interrupted.
Adult green frogs stay in the water or its immediate vicinity all the time, only overwinter on land. They are active during the day, when they sunbathe on the shore of the water or on a floating leaf of a water-lily or water-plantain, or watch for invertebrates with which they feed. Particularly the thick-headed frogs, which are the largest of our green frogs, also tackle larger prey, for example larvae of other amphibians, small fish, bird chicks and small mammals.
Breeding of green frogs takes place from May to July. At that time the males during the day and late into the night loudly call the females. They lay spawn of irregular shapes on submerged parts of aquatic plants, so their spawn is not easy to find.
Green frogs are distributed throughout Slovenia. We find them in various types of standing or slowly flowing waters with at least some aquatic vegetation. The fish fauna doesn't bother them either. Nevertheless they are cautious, shy and quick. If we approach them too quickly, they do not hesitate, but immediately jump into the water, dive, and then do not appear again for several minutes.
All three species of green frogs are protected in Slovenia and are listed on the Red List of endangered amphibians in the category vulnerable (V) species!
P painted frog (Pelophylax lessonae) is the smallest among the trio, the body length of an adult ranges from 4 to 9 cm. The most characteristic part of the painted frog's call is the loud and stretched krrrrreee.
Debeloglavka (Pelophylax ridibunda) is a large frog that grows from 5 to 15 cm. Males can be heard repeating their staccato ke-ke-ke-ke-ke even up to two kilometers away.
Green frog (Pelophylax kl. esculenta) grows from 5 to 15 cm. The pattern and color of its body and also the males' calls are often similar to either the painted frog or the thick-headed frog, which is not surprising, since this species arose from an unusual form of crossing of the parental species – the green frog and the thick-headed frog. The peculiarity of the origin of this species is also indicated by the abbreviation kl. in its scientific name.
