Agile frog
Agile Frog (Rana dalmatina )
The agile frog (Rana dalmatina ) is within the order of Anura to the family of the Real frogs and also to the genus of the Real frogs.
Features
Spring frogs are slender, long-limbed anurans with a pointed snout. The head -body length of the males is rarely more than 6.5 inches that. Females to 9 inches The top is light brown, reddish brown or pale gray-brown ( "fall foliage colors " ) and comparatively recording and contrast. The brown frog typical triangular temporal patches to the tympanic membrane are dark brown. The underside is whitish and usually quite unspotted. During the mating season the males are often in the water turns dark brown. Show dark transverse bands but no single species-typical feature on the upper and lower legs. The hind legs are remarkably long, so the style is very sharp moving images: they can make one to two meters wide sets. The pupils are horizontal; the iris is in the upper third (above the pupil) bright golden color as the side and below the pupil. The eardrum reaches approximately the size of the eye diameter and is in each case very close behind the eye. The glandular ridges on the back are not very strong and pronounced interrupted in places.
Reproduction
The males migrate in the fall to the spawning grounds in order to winter there. The females overwinter in waters close to shore. The mating call of the male consist of fairly quiet tone rows, like " ... weighed weighed weighed ... " sound and will last up to 12 seconds. It is often called even under water, so that the vocalizations of the observers perceive only at close range. But on the few -day peak of the spawning period, the animals also form Balzchöre at the water surface. In Central Europe the spawning season is often about in the first and second decade of March - may be due to the weather but also delay. The agile frog is thus spawning active first Froschlurchart in the spring. This is interpreted as " avoid competition " over other early spawning amphibians.
The spawning bales 450-1800 eggs are preferably attached in water depths of between five and 40 centimeters of branches, roots or plant stems. So they rarely sink to the sea bottom. The spawn clump not concentrate as common in moorland and particularly at grass frogs, at a certain point in the water, but are distributed more widely. The upper pole of the egg in the spawning is dark brown to black, the under side there is a small, bright, sharply defined spot. The diameter of the individual ice without the gelatinous envelope is 1.5 to 2.1 millimeters.
The tadpoles of Flossensaum is relatively high, especially in the first third of tail. The tail is two to 2.5 times as long as the hull and ends pointed. The abdominal region is pigmented " grainy " and intense. The total length reaches 60 millimeters, the larvae of the grass frog surpasses anything.
Habitat and Distribution
The agile frog preferred clear abundance of water and mixed deciduous forests. The open land around is also populated, as long as this is linked via bushes rows with the forest. As spawning grounds serve forest pools, ponds, small ponds and ditches. Fish -free waters with sunny littoral zones are ideal. The species often lives far away from the water in rather warm dry forests ( low and medium forests). Of the three central European brown frog species, it is the most thermophilic and trockenheitstoleranteste.
The range extends from France to parts of Germany, the Czech Republic, Austria, Hungary, Italy, through the Balkans to Greece and the Black Sea. In Germany the dissemination image is a disjoint patchwork with a focus on Central and Southern Germany, for example, in the Bay of Cologne, in the Saarland, in the northwest of Baden- Württemberg and the Upper Rhine in Swabia, in parts of Bavaria and in Central Saxony. To the north, the incidence solve more and more on to small, isolated islands; those located in the northern Harz mountains, in the Lüneburg Heath, of Pomerania and am Darß.
Threats and conservation
The strong verinselte distribution in northern central Europe requires a spatial and genetic isolation of individual populations. A major hazard cause is in addition to direct habitat destruction of motor vehicle traffic on the dense road network: When wandering between the partial habitats, including from winter quarters to spawning grounds, are in addition to other amphibians ( see for example: common toad, common frog ) run over and jumping frogs. In addition, artificial fish stocking in small bodies of water lead to the extinction of the frog stocks.
Legal protection status (selection)
- Fauna-Flora -Habitat Directive ( FFH Directive ) Annex IV ( strictly protected species )
- Federal Nature Conservation Act ( Federal Nature Conservation Act ): strictly protected
National Red List classifications (selection)
- Red List Federal Republic of Germany: not threatened
- Red List of Austria: NT ( Near Threatened )
- Red List of Switzerland: EN (corresponds to high risk )