The Cocoi Heron, also known as Ardea cocoi, is a bird species that exudes elegance and charm with its stunning plumage and long, slender bill. This fascinating bird can be found in the lowlands and wetlands of South America, where it graces the landscape with its majestic presence.
During the breeding season, the Cocoi Heron undergoes a transformation. The bill becomes a brighter yellow with a red base, and the back, lower neck feathers, and crest grow longer. Legs take on a reddish hue, and the facial skin becomes more vibrant. Juvenile Cocoi herons resemble adult birds but with a greyer appearance on the neck, thighs, and undertails.
Vocalization is common during roosting or at colonies, with the Cocoi Heron emitting a distinct ‘rraahbm rraabb’ guttural call. In flight, it produces a series of ‘gawk uk, guk uk, guk uck uck’ sounds. The diet of the Cocoi Heron consists mainly of large fish, aquatic insects, and amphibians like frogs. They occasionally consume dead or dying animals. These herons are solitary hunters, but they may feed in groups if food is abundant.
The Cocoi Heron’s range spans across most of South America, except for the high Andes. From Panama to Chile and Argentina, these birds can be found foraging along rivers and marshes. Although most are believed to be sedentary, some birds in the southern regions may migrate to northern parts of South America during the winter.
Breeding season timing varies by location, occurring in July in Surinam and between August and November in Brazil and Argentina. Cocoi Herons construct their nests in trees, bushes, or reedbeds using a combination of reeds, twigs, and grass. One clutch of 3-4 light blue eggs with white speckling is laid by the female, and both parents take turns incubating them for about 26 days. The young birds stay near the nest for up to 12 weeks before beginning to explore their surroundings at around 6 weeks old.
With a potential lifespan of up to 25 years, the Cocoi Heron is a captivating species that adds to the charm and diversity of South America’s avian world. Its unique characteristics and behaviors make it a fascinating subject of study and admiration for bird enthusiasts and nature lovers alike.