Natterjack toad
Natterjack toad (Bufo calamita )
The natterjack toad (Bufo calamita; yet controversial new synonym: Epidalea calamita ) is a Froschlurch from the kind of genuine toads within the family of toads ( Bufonidae ).
Features
The size of the males ranges from four to seven centimeters, the. Females from five to eight centimeters The back is mottled brown or olive color on a lighter background. The skin surface is dry and warty. The large warts as well as the parotid glands at the back of the head are sometimes reddish colored. About her " cross" ( the back) runs normally ( but not always) a thin yellow longitudinal line. The body is compact, the head falling away to the front, rounded snout, the pupil horizontally elliptical, the iris lemon yellow to greenish. The hind legs are very short for toads conditions so that toads hopping rare, but move characteristically mouse -like crawling forward.
Reproduction
The males during the spawning period with the help of a blue colored, big, throat permanent vocal sac loud mating calls to make reproductive females willing attention. The Rufserien can be described as a loud metallic Rätschen ( " Ärr ... Ärr ... Ärr "). Nocturnal Cross Toad Rufchöre are sometimes almost two kilometers to hear. In Central Europe the Hauptrufperiode is in April and May. Depending on weather conditions but is already an earlier start of calling (end of March ) or will find it in the summer months - triggered by extensive rainy periods - more reputation and spawning periods instead. The calls can be phonetically confused with those of the nightjar.
The one - or two-row pearl necklace -like, one to two meters long spawning strings are stored in the shallow water directly on the bottom without reference to plant stems or other vertical structures. You are not sure of which to distinguish in each case the common toad, but usually spawns earlier and the Eischnüre preferably anchored to something deeper water sites between stems and submerged branches. The number of black eggs is from 2800 to 4000, wherein the Eidurchmesser is one to 1.7 millimeters.
The dark, small tadpoles resemble those of the common toad; from the stage of maturity with hind legs they have, however, often a vague, bright throat patch. Its length including the tail rudder is up to 36 millimeters. Under favorable external conditions toads tadpoles only need three to six weeks until metamorphosis. The duration of larval development is affected by, among other things, the water temperature, food supply, the population density, competition with other larvae and the threat of drying out of the water. The minimum duration of development in the field are 17 days, and maximum delivery time can be 84-100 days.
Habitat and Distribution
Just like the toad, the natterjack toad is a pioneer species warm, open habitats in areas with loose, sandy soil. The presence of vegetation - free to poor habitats with adequate hiding places as land habitat and scarcely vegetated flat and small bodies of water as spawning areas is a prerequisite for the existence of the natterjack toad.
The preference for very shallow small bodies of water for the settling of the spawning cords one hand harbor the risk of dehydration before the larvae have completed their metamorphosis. On the other hand, offer such habitats the advantage that they heat up very quickly and no predators are in the water. The loud cry of the natterjack toad is adapted to pairing in annually changing waters, the partner must be attracted not only to the male toad, but also to the corresponding unknown waters. Be colonized Abgrabungsflächen, inland dunes, mining landscapes, wastelands, construction sites, military training areas, coastal dunes, salt marshes and ruderal in the human settlement area. Even in structurally poor agricultural landscapes, the species is sometimes encountered, if suitable spawning habitats are available.
The distribution of the species extends into western, central and northeastern Europe from the Iberian peninsula on the southern tip of Sweden to the Baltic States and Belarus. In Germany, the Natterjack Toad is coming - however scattered and discontinuous - in much of before; There are gaps, especially in low mountain ranges. In many regions of the stocks are apparently declining.
On some North Sea islands with dunes the natterjack toad, however, is the most common amphibian species. Contrary to earlier assumptions, this is not, however, at a very high salt tolerance, but because the dunes and sandy foreshores of the natterjack toad grant an advantage over other amphibian species here.
Threats and conservation
As Pionierbesiedler vegetation poor dry biotopes with smaller, often sporadic water retention toads suffer from the lack or too rapid drying out of suitable spawning grounds and under the bush encroachment and shading their habitats. Particularly affected are but of interventions such as reclamation or reuse of derelict land and former soil degradation pits. Since the flood plains in central Europe are often strongly affected by straightening and dike construction in their hydrological and surface structural dynamics, no natural habitats for toads may occur more often there.
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: V - early warning
- Austria's Red List: CR (corresponds threatened with extinction )
- Red List of Switzerland: EN (corresponds to high risk )