Identification: It sizes 17–17·5 cm.
Male has forehead to nape blackish, long, broad white supercilium, very thin white crescent below the eye, blackish lores, ear-coverts and neck, white triangular patch on lower neck side; upperparts blackish-brown.
Female distinctly paler and greyer above, but still showing a distinctive combination of feathers as male.
Juvenile Like washed-out female; less distinct head pattern, dark malar stripe, smudgy greyish breast.
Habitat: The Mekong wagtail is found in wide lowland river channels. Territorial birds are associated with fast-flowing braided sections of river which flow through a distinctive landscape of rocks, bushes adapted to prolonged seasonal submersion, mainly Homonoia riparia, with sandbars and gravel shoals.
Ecology: It breeds in riverine “channel mosaic” habitat, typically in broad, lowland rivers, where the streambed is exposed to provide rocky outcrops and bushland, gravel shoals and/or sandbars, tufted grasses and annual dicotyledons. It avoids wooded areas. It will regularly feed within bushes in the water, walking along branches and picking food items from these and from leaves.
Conservation status: Near Threatened