Photo: Gregory Wheeler, via iNaturalist, public domain / CC0. Unmodified apart from resizing.
Region
Singapore and tropical Asia, Japan and temperate East Asia
Habitat
rivers and wetlands, coast and mangroves
Colour
white, black, yellow
Size
large (over 50 cm)
The field notes for this species (identification, habitat, season and photography advice) are written in Chinese; switch to 中文 to read them. The facts follow the sources below.
Field ethics: keep a distance at which the bird does not change its behaviour; never approach or publish nest sites; no baiting, playback or flash; never clear vegetation around a nest; follow reserve rules and stay on paths.