Amphibians are a particularly endangered group of animals. Of the 20 amphibian species documented in Bavaria, twelve are on the so-called red list, it says on the part of the Bavarian State Office for the Environment. All species are still native to Lower Franconia. But how much longer?
The populations of these species are declining across Europe. As early as 1992 it was decided to protect the most important occurrences in European nature reserves, the so-called fauna-flora-habitat areas (FFH areas). The fact that the management plans in Lower Franconia are often not enough for the populations to recover is shown by a request from Patrick Friedl, member of the state parliament of the Greens from Würzburg, to the Bavarian state government.
The largest newt species in Lower Franconia, also known as the “water dragon”, is threatened in the region. Of the 19 areas designated for the crested newt in Lower Franconia, biologists have discovered good populations in just six areas. In many areas the population of newts is moderate to poor, in four areas the species is even considered lost, for example in the Schweinfurt city forest. The crested newt can still be found in the Vorderen Steigerwald with the Schwanberg (district of Kitzingen), in the Zellinger community forest (district of Main-Spessart), at the training area “Brönnhof” (district of Schweinfurt) and in the forests near Bad Kissingen and Münnerstadt ( District of Bad Kissingen).
The situation for the yellow-bellied toad is even more dramatic. The four centimeter tall frog with the yellow belly side is known for its prophecies of doom. The yellow-bellied toad could only be detected in nine of the formerly 20 protected areas in Lower Franconia in 2020. In five of these areas, their populations were moderate to poor. The yellow-bellied toad can still be found, for example, in the Nordsteigerwald or in the quarries near Kirchheim (district of Würzburg).
“There are only residual deposits in areas that were previously networked. If you do nothing, they will die out.”
Ulrike Geise, biologist at the Bund Naturschutz–
But the locations are far apart. “There are only residual deposits in areas that were previously networked. If you do nothing, they will die out,” says Ulrike Geise, amphibian expert at the Federal Nature Conservation Union. In order to explain to laypeople why the Main once again produced new amphibian populations, the biologist likes to pull out an old doctorate from 1923. It is about making the Main between Frankfurt and Würzburg navigable and expanding it to a depth of 60 centimeters. For comparison: Today the federal shipping route is almost three meters deep and is “narrowed into a canal,” said Geise.
Since the Main used to carry no less water and the Main valley was also no wider, one can imagine how the river expanded in width at that time – especially during floods, explains Geise. With small pools, puddles and different depths and shallow waters at the edge. But this “backbone of the amphibious society in Lower Franconia” gradually collapsed when the Main was made navigable. Habitats for the amphibians were lost. Then there is the danger from road traffic, deadly fungal diseases and tidy landscapes.
“Amphibians are an important part of the food chain. Interventions in food chains can always be felt at some point.”
Dieter Mahsberg, zoologist–
In the opinion of the biologist, in order to save the crested newt where it still exists, one would have to create a water network within a radius of 1000 meters and regularly check the fish population in the ponds so that the last newts are not eaten away by fish. The yellow-bellied toad urgently needs puddles – in the garden, forest or in the field instead of proper gardens and paved paths. The problem, according to Geise: In Bavaria, the management plans in FFH areas are relatively generalized. Individual species fell through the grid. Furthermore, it often takes decades before measures are implemented. “These are periods of time that small populations can no longer manage.”
Would it be bad if amphibians, which were the dominant group of vertebrates on earth more than 300 million years ago, became extinct in Lower Franconia? The zoologist Dieter Mahsberg and former director of the Department of Animal Ecology and Tropical Biology at the University of Würzburg says: “Amphibians are an important part of the food chain.” The tadpoles of frogs and toads eat plants underwater. Adult toads often feed on nudibranchs. And the larvae of the newts eat mosquito larvae. “Interventions in the food chain can always be felt at some point.”
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