The agile frog (''Rana dalmatina'') is a European frog in the genus ''Rana'' of the true frog family, Ranidae.

Description

This species is fat and has long limbs and a pointy snout. Adult males are rarely larger than 6.5 cm, while females can grow up to 8 cm. Its dorsal surface is

light brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model used ...

, reddish-brown, or light greyish-brown with very little contrast. Triangle-shaped spots reach from the temple to the

eardrum In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear The outer ear, external ear, or auris externa is the extern ...

, which are

dark brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model use ...

. The underside of the agile frog is white without any spots. During mating season, the males often become dark brown. The hind legs are unusually long, which allow this species to jump further than other similar frogs - they have been known to jump up to two metres in distance. The pupils are horizontal. The colour of the upper third of the iris (above the pupil) is lighter and gold in coloration. The tympanum is about the size of the diameter of the

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

. The

gland In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

stripes on the frog's back are not very developed and partially interrupted.

Distribution

The agile frog can be found in France, the Channel Islands, parts of Germany, Denmark,

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, Italy, the Czech Republic, Slovakia, Austria, Hungary, on the Balkans, Greece, and by the Black Sea. The species once lived in the United Kingdom, during middle

Saxon The Saxons ( la, Saxones, german: Sachsen, ang, Seaxan, osx, Sahson, nds, Sassen, nl, Saksen) were a group of Germanic * * * * peoples whose name was given in the early Middle Ages to a large country (Old Saxony, la, Saxonia) near the Nor ...

times, with

archaeological Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscap ...

remains recovered in

East Anglia East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...

. Celtic Reptile & Amphibian have discussed

reintroducing Species reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse, self-sustainin ...

the species. It has undergone a reintroduction on Jersey, by Durrel Wildlife Conservation Trust, as it was very close to extirpation on the island.

Reproduction

The call is a fairly quiet "rog ... rog ... rog", and can last for up to 12 seconds, and almost sounds like a clucking chicken. They often also call under water, so the calls can only be heard from a very short distance by observers. Spawning only lasts a few days, and during this period, the males sometimes gather in large calling groups on the water surface to attract females. In Central Europe, spawning usually occurs in the first 20 days of March, but can also be delayed, depending on the weather. The spawn clumps consist of 450 to 1800 eggs, and are usually attached to tree branches, roots, or plant stems at depths of . Therefore, they rarely sink to the bottom. Unlike the

moor frog The moor frog (''Rana arvalis'') is a slim, reddish-brown, semiaquatic amphibian native to Europe and Asia. Moor frogs are known for their ability to freeze solid and survive thawing. The frog makes use of various cryoprotectants i.e. antifreeze ...

(''Rana arvalis'') and

common frog The common frog or grass frog (''Rana temporaria''), also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog, is a semi-aquatic amphibian o ...

(''Rana temporaria''), the agile frog does not lay its spawn all in one clump. The diameter of a single egg, not counting the gelatinous shell, is .

Habitat

The agile frog prefers light deciduous mixed forests with plentiful water. The open land around a forest is often also populated, as long as it is connected to the forest by shrubs. In dry, warm forests, this species often also lives far away from the water. Of the three Middle European ''Rana'' species, this frog likes warmth and dryness the most.

References

External links

* {{Taxonbar, from=Q545917 Rana (genus) Amphibians of Europe Amphibians described in 1839