Habitat use of the common spadefoot toad (Pelobates fuscus) in Estonia

Habitat loss and degradation are the most obvious and acute factors which influence amphibian decline. Fortunately, however, habitat deterioration is potentially reversible. Recognizing the factors critical for the species is therefore essential for successful habitat restoration and maintenance. In this study we explored the habitat requirements of the common spadefoot toad (Pelobates fuscus), a severely declining species in Europe. The toad is considered a typical representative of herpetofauna in open agricultural landscapes but at its northern and western range edge the species occurs also in forested areas. So far, studies on the habitat requirements of the common spadefoot toad have only focused on agricultural areas and the significance of forest habitats has remained indistinct. In order to determine the habitat characteristics vital for the species as well as the function of forests as possible sink or source habitats, we explored 34 water bodies and their surroundings comparatively in forested and open landscapes in Estonia. Our study demonstrated that land cover type did not influence the presence of the species – the limiting habitat factors were related to soil type and quality of the reproduction site only. Respectively, the species preferred large fish free sun exposed water bodies in areas with sandy soil. In our study sites such conditions were best met in old growth coniferous forest areas. Thus we suggest that these types of forests holding viable populations of the common spadefoot toad should be protected with large scale clear cuttings as well as altering of hydrology avoided.