Argentina, Bolivia, Brazil, Chile, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay (B), Venezuela.
Unknown to Ecuador.
Northern Colombia through northern Venezuela, Trinidad and Guyana to Surinam. Allso southern Bolivia and southern Brazil to central Argentina and central Chile.
 
Population
Estimated population is 100,000 - 1,000,000 (2010).
Stripe-backed Bittern (Ixobrychus involucris) [XC17035]
by Bernabe Lopez-Lanus from Km 79, Transchaco Hwy. W of Asuncion, Paraguay (call)
Stripe-backed Bittern (Ixobrychus involucris) [XC45683]
by Fernando Igor de Godoy from Estancia El Potrero, Gualeguaychu_Entre Rios, Argentina (call, call 'horororoc')