Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands (Malvinas), French Guiana, Guyana, Panama, Paraguay, Peru, South Georgia and the South Sandwich Islands, Suriname, Trinidad and Tobago, Uruguay (B), Venezuela.
Vagrant to St Helena.
Most of southern America excluding Andes, from eastern Panama south to Aysén (Chile) and Chubut (Argentina).
 
Population
Estimated population is 100,000 - 1,000,000 (2010).
Cocoi Heron (Ardea cocoi) [XC476510]
by JAYRSON ARAUJO DE OLIVEIRA from Piscicultura - Goi\u00e2nia, Goi\u00e2nia, Goi\u00e1s, Brazil (flight call, song)
Cocoi Heron (Ardea cocoi) [XC381844]
by id from Pouso Alegre, Mato Grosso, Brazil (call)