[4] The bill is pink with blue to violet at the base and the distal third black, the legs are greenish and rather short, and there is a fairly big area of bare bluish skin around the eye.

[4][5] Juveniles have the same overall pattern but are duller than adults, with the crown lighter, the breast light gray, and the throat and sides unstained white.

[4] The alarm call is a harsh quah-h-h.[5] Unlike other herons, in flight it has fast, duck-like wingbeats and usually does not retract its neck fully.

[4][5] The subspecies sibilatrix inhabits eastern Bolivia, Paraguay, western and southern Brazil, Uruguay, Chile, and northeastern Argentina.

It makes seasonal movements at least in northeastern Venezuela, where it does not occur from November to January, but remains all year in other areas, such as Buenos Aires Province, Argentina.

[4] It occurs at elevations up to 500 m (with a sight record from 2300 m[6]) in seasonally flooded savanna, often in drier grassy situations than other herons, but also in a wide variety of open waterlogged or shallowly submerged terrain.

[7] This species eats any small dryland and marsh animals it can catch, or even pirate[4] (as from an aplomado falcon in one reported incident[7]).

It often holds still[4][5][6] but also walks very slowly[7] and may use more active techniques, even running after prey or catching flying insects (notably dragonflies[6]) from a standing position.