Kleintiere englisch

The small animal world in the Sontheim Cave

The Sontheim Cave represents a special and very extreme habitat in our homeland. Lack of light, constantly low temperatures, high humidity and little food are the most essential factors that characterise the habitat in a cave. In Sontheim Cave, the low temperature is particularly striking. This is due to the steeply sloping entrance area, through which the cold air flows into the cave in winter. When you descend into the large entrance hall, you enter a cold air collection basin, so to speak. At the deepest point, temperatures of only 5 °C are measured there even in midsummer. In winter, ice stalagmites and cave ice form there and last until March. Only after the bat gate does the cave slowly become warmer. But 7 °C is hardly ever exceeded at ground level. The entrance hall of the Sontheim Cave is thus one of the coldest places in the middle Alb and represents a unique habitat in our region with almost arctic conditions.

The creatures find good living conditions here. The cold does not seem to affect them too much. It is striking that the cave cross spider Meta menardi, which is otherwise common in all cave entrances, is hardly ever found in the Sontheim cave. This damp-loving animal needs draught-free niches leading up into the rock. Such places are missing in the huge entrance hall, which is characterised by frost blasting.

Compared to the dry and cold entrance hall, the regions of this cave far from the daytime are partly very damp, so that puddles and pools of water form in some places. The real cave animals are blind and colourless. They feed on fungi that grow on bat excrement or eat dead animals. Others feed on pollen and organic material that accumulates on the water surfaces of the puddles, carried in by the cold air flow.

The animals found in the final hall showed typical adaptations to life in a cave. For example, all the springtails found there were blind and colourless. One tiny predatory mite also had extremely elongated limbs with which it orientates itself in the eternal darkness. Even mosquitoes live here. These are fungus and fungus gnats, some species of which can even complete their entire life cycle in the caves. Their larvae then live predatorily on the cave walls.

A special find is the double tail (Fig. 28), a proto-insect that can sometimes be observed on the water surface of puddles. The animal still shows very original body features, which document the insects‘ relationship to millipedes.

Fig. 28: Double springtail

Christian Fischer (abridged)

Further information in the brochure on Sontheim Cave, available at the cave ticket office.