Last Updated: Aug 25, 2011
The boat-billed heron (Cochlearius cochlearius) is a solitary species found in mangrove swamps and near freshwater, especially rivers and wetlands. They are nocturnal, though the species is known to spend days not only sleeping but also preening and quietly roosting. During mating season however, these herons may hunt and feed during the day, as well.
Scientific Name: Cochlearius cochlearius
Status in the Wild: Common
Habitat: Marshes, Rivers, Swamps
The boat-billed heron is part of the night heron family, distinguished by a stocky build, short legs, and a unique bill. Both male and female boat-billed herons grow to approximately 20 inches long and weigh just over a pound. Their short, flat and wide beaks are as broad as their entire heads. Adults have silver-grey plumage accented by a black crown and upper back, while juveniles are much browner. Their large eyes, ideal for nocturnal hunting, are dark brown with a yellow-green eyelid. The boatbill is an unusually noisy heron, having a raucous call that can be heard along the tropical mangroves and forests. Their call is often likened to a toad croak or loud squawk, especially when the bird is in distress.
Boat-billed herons are mostly carnivorous, eating fish, worms, insects, amphibians and crustaceans. Experts believe that they rely on touch, not sight, to catch their prey. They use sound to communicate with others of their species, listening for forest sounds to detect movement and rattling their bills to signal distress.
The boat-billed heron is found in Mexico down through Central and South America, as far south as Peru and Brazil. They live primarily in mangrove swamps and lowland tropical forests, and are both solitary and social birds. Though they nest in small colonies of only two or three birds, they roost in groups of up to 50 individuals.
In Costa Rica, boat-billed herons are common along both the Caribbean and Pacific coasts. They live at elevations ranging from sea level to 600 feet and are often spotted in Tortugero National Park, Corcovado National Park, Palo Verde National Park and Carara National Park.
Mated pairs put on an elaborate show: males raise their crest and both birds chatter with their beaks. These herons nest solitarily or, less commonly, within small colonies that may be made up of a mix of waterfowl.
Boat-billed herons nest in trees, bushes, or reed beds. Both males and females participate in nest building, incubating, and feeding the chicks. Clutch size generally ranges from two to three eggs, although first clutches may contain three or more bluish eggs. The incubation period lasts 21-16 days and chicks are born altricial, meaning that they are blind and dependent on their parents for food. Chicks remain in the nest for six to eight weeks.
Status in the Wild:
The boat-billed heron is not considered a threatened species. However, as humans encroach on their native habitats, their breeding habits have changed. Studies show that human presence disturbs female nesting, and may result in fewer hatchlings.