This grey-brown waterbird has a black mask from face to throat in males. A Bangladesh study documented nests in trees beside narrow waterways in the Sundarbans.
The overall plumage is grey-brown, and the bill is colorful. The male has a particularly dark black mask extending from the face to the throat.
A 2011-2014 study in Bangladesh's Sundarbans found 25 nests along the edges of vegetation beside narrow creeks. Many were in mangrove trees.
It swims with a back-and-forth head motion and forages by picking food from the surface or diving.
The male has a thick yellow bill, gray hindcrown and hindneck, and a black face and throat bordered in white. The feet are bright green.
Females have a whitish throat, upper foreneck, and lores, with less black on the forecrown. Juveniles resemble females but are browner above and lack black on the forecrown.
An extinction-risk assessment has not been added yet.