A very large, long and slender bird. Bigger than Grey Heron. Plumage grey, with contrasting black throat and flight-feathers. White sides of neck. Tertials forms fluffed, ostrich-like rear end. Red crown visible at close range. Easily told from herons in flight by the straight neck. Juveniles with rufous head, lacking the marked pattern of adults.

Powerful, resonant and bugling "kriiiiioooo" in various forms. Very far reaching. Often heard in duet where the female immediately answers the male call at a slightly deeper pitch. Also very vocal when flocks meet.

Call, male/female:

Wikipedia: map (se also Xeno-canto below)

Birdlife ecology

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC-sound:Piotr Szczypinski, Licence,Link.