Environmental DNA surveys and the following physical field surveys suggest that small headwater streams likely serve as important habitats for juveniles and larvae. While habitat degradation threatens the Japanese giant salamander, it can inhabit disturbed streams surrounded by agriculture fields such as rice paddy fields. Adults appear to do well in a stream surrounded by rice paddy fields because rice paddy fields provide habitats for frogs, which serve as primary diet for adult giant salamanders in such a stream.
Environmental DNA surveys and physical field surveys suggest that small headwater streams are likely important habitats for juveniles and larvae of Japanese giant salamanders. While habitat degradation threatens the species, it can inhabit disturbed streams surrounded by agricultural fields such as rice paddy fields. Adults appear to thrive in a stream surrounded by rice paddy fields because rice paddy fields provide habitats for frogs, which serve as the primary food source for adult giant salamanders in such a stream.