The endangered yellow-bellied toad's spawning grounds are increasingly being destroyed, but conventional amphibian conservation measures are of little help. Biologists have now uncovered one reason for this: the endangered amphibian species can reproduce best in newly created, short-lived small bodies of water. It therefore benefits little from long-term ponds. The yellow-bellied toad, on the other hand, finds ideal conditions in man-made puddles, such as those that form in the lanes of unpaved forest roads.
The yellow-bellied toad is a sight to behold, with its heart-shaped pupils and yellow and black patterned abdomen. But in the mountain and hilly landscapes of the southern German forests, which represent a main distribution area of the small frog, this species can only rarely be sighted. This is because small bodies of water such as ditches and puddles, which the yellow-bellied toads use as spawning grounds, are increasingly being polluted or destroyed by the introduction of waste, environmental toxins and fertilizer. For this reason, the species is strictly protected and is supported, for example, with the artificial creation of water bodies in the search for spawning grounds.
spawning ground through forestry
In order to be able to further improve species protection in the future, researchers from the University of Hohenheim in Stuttgart have evaluated existing measures and developed a sustainable protection concept for the creation of spawning waters for the endangered species. To do this, they examined the effect of permanently created bodies of water and temporary water points and came to the conclusion that the yellow-bellied toad does not benefit in the long term from permanently created bodies of water for amphibian protection: "In the first year of the study, the yellow-bellied toad reproduced particularly well in dredging ponds," reports Felix Schrell, Research project coordinator. But: “In the second year already, predators of the yellow-bellied toad settle in these permanent waters. The offspring of the pioneer species then has no chance of surviving. Even a remediation of these waters, as is often done for the yellow-bellied toad, does not bring any population-preserving reproductive success.
According to the researchers, conventional protective measures are of little help to the endangered toad. Instead, their results pointed to another concept that proved to be significantly more effective: "Tracks left by forest machines on skid trails create ideal spawning waters for the yellow-bellied toad," says Martin Dieterich, head of the research project on the sustainable protection of the yellow-bellied toad. The lanes on forest paths offer space for temporary small bodies of water, which are regularly used during the course of the timber harvest. This means that there are always new spawning waters that are free of vegetation and therefore do not attract competing species and predators - ideal for the spawning of the yellow-bellied toad. As the scientists' results show, this develops particularly quickly in the new puddles.
Species protection in everyday forest life
According to Dieterich, the results also show that forestry can certainly make a contribution to species protection: "The yellow-bellied toad survived in Baden-Württemberg not despite forestry, but because of it," he says. In the case of the toad, species protection must therefore be integrated into forest use. The research team has developed practical guidelines for this: Tracks in the forest are to be preserved during the spawning season of the yellow-bellied toad over the summer and only leveled afterwards. Since the lanes are created during forest work anyway, there is no particular additional effort for species protection in forestry. In order to create spawning waters outside of the skid trails, lanes could also be created on wild fields in spring and removed again in the course of regular tillage in autumn.
So far, it has been common practice to level the newly created lanes on back roads immediately after forest work or to cover the roads with brushwood as a preventive measure so that no puddles form. In this way, foresters try to avoid possible complaints from the population or from nature conservation associations - because in the public perception the lanes are generally considered to be a destruction of the forest ecosystem. Therefore, another important aspect of the new protection concept is to convey to the population through public relations work that species protection and forest management go hand in hand in the case of the yellow-bellied toad.
Source: University of Hohenheim