The European green toad, Bufotes viridis, in Donaufeld (Vienna, Austria): status and size of the population

The European green toad, Bufotes viridis (Laurenti, 1768), is a rare and protected species in Vienna. In spring and summer 2020, we conducted a survey to assess size and status of its population in Donaufeld, an agricultural area designated for real estate development. Recaptures of photographically registered toads allowed to estimate the population size with 137 individuals (confidence interval: 104–181). Comparatively large body size indicates the presence of a well-established population. Reproductive success was high in the study year. A mismatch mating of a male B. viridis with a female Bufo bufo was observed. Mitigation measures are needed to support this population facing imminent habitat deterioration.