“We only saw Japanese Wagtails (Motacilla grandis) twice and in rivers with gravel stones. We were fortunate to observe (from some distance) an adult pair feeding a single juvenile. Both parents were feeding the young.
Photo at the top shows the habitat with a juvenile and adult in the image. Photo above shows an adult with prey for the juvenile and photo below shows an adult with prey caught for the nearby juvenile from the river (not rocks or banks). The one prey I saw able to determine was an aquatic Plecoptera (Stoneflies) nymph.
Below is a photo of a juvenile.
Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
9th June 2019
Location: East Hokkaido, Japan