Figure 5.7.14 – Comparison of two pond scenarios. A: The construction of one large retention pond is less favourable. The chances of breeding success for amphibians are lower because if the pond becomes unsuitable for reproduction (e.g., eutrophication), there will be no other places to breed nearby. B: Providing multiple ponds is optimal, as several ponds of different sizes beside terrestrial habitats are present on both sides of the road, increasing the chances of breeding success for amphibians. Amphibian passages allow migrations to take place from one side to the other (Source: Adapted from Langton et al., 2001; EGIS).