Early amphibian colonizers of man-made mini-ponds: first results of a citizen science experiment

The loss of suitable spawning habitats is a global threat to amphibians. Thus, establishing man-made ponds may serve as a successful conservation practice to counteract this threat. In this experiment, we used a citizen science (CS) approach to create mini-ponds in private gardens and asked participants to monitor amphibian activity. We provided 302 polyethylene mini-ponds (120 L × 90 W × 40 D cm) to citizen scientists across the range of the target species, the European green toad ( Bufotes viridis ), in Austria. In the first year of the experiment (2024), B. viridis and 12 other amphibian taxa were recorded at 38% of the monitored sites. Signs of amphibian reproduction were detected in 10% of the mini-ponds. Bayesian occupancy models showed detection probabilities consistent with other studies. Over time, we expect more amphibians to discover the mini-ponds and more individuals to use them for reproduction. Our experiment demonstrates that the creation of relatively small ponds is a promising method for supporting and monitoring amphibian populations.