Is the European tree frog returning?
Foto: Frank Körner
The European tree frog used to be common and widespread in Lower Saxony. It could be frequently observed - particularly in late summer and early autumn; this is the time when the frogs enjoy the warming sun rays on the leaves of shrubs and trees. Especially on blackberry-picking excursions, one could encounter the little green frogs just about everywhere.
Today, however, the European tree frog has disappeared from numerous areas and is ranked on the Red List of endangered species. It used to be widespread also in the lowlands of the Rottbach brook to the south of the Nienburg District near the border to North Rhine-Westphalia. Blackberry hedges can still be found here; spawning grounds for successful reproduction of the frogs, however, are missing. LIFE-AMPHIKULT aims at finding a solution for this situation. Currently, plans are underway for the new water bodies. Weather permitting, excavators will pull in this winter. ”Whether the European tree frog will accept the new ponds depends on various factors”, according to Dr. Markus Richter, project manager of LIFE-AMPHIKULT. “It is vitally important that there are close-by European tree frogs that are able to overcome the distance between old spawning grounds and new water bodies.”
To deal with this question, the project was assisted by Gunnar Mügge from Sulingen, who volunteered in the field mapping of the amphibians. He spent countless nights looking out for European tree frogs in the districts of Diepholz, Nienburg and Minden-Lübbecke. Thanks to their loud mating calls, the males are relatively easy to spot at the spawning grounds. The positive result of this nightly quest was the locating of calling males at three sites near the Rottbach brook. Even though only individual males could be heard and the populated water bodies are hardly suitable for a successful reproduction, the species has evidently not yet totally disappeared from the area. This augurs well for the return of the European tree frog to the Rottbach brook.