This bird, which draws its name from the peculiar shape of its beak, has a large wingspan and can be found in Central and South America.
Chestnut-headed Oropendola Distribution
The Chestnut-headed Oropendola can be found from Southern Mexico through Central America and into the Northeast of Colombia and Northern Ecuador. The birds are often found along the edge of the forest, or in the forest canopy. Orpendolas frequent lowlands, old plantations and the coast as their primary areas of habitation.
Mating & Reproduction
In a colony of Chestnut-headed Oropendolas, there on average five females to every one male. This makes for a non-competitive seemingly polygamous mode of existence for these birds. Colonies appear to stay together and breed from January to May.
Much of the colonies are found to have lower numbers of males due to the large amount of expended energy used for raising male chicks. Females are two times as likely to survive through adolescence, whereas male birds do not fledge until they are nearly two times the weight of their female counterparts.
Chestnut-headed Oropendolas build large colonies with 56 cm sac like nests which they hang from trees near to one another. The colonies generally consist of between 12 and 50 birds, and they form their large sac shaped nests of vines, Spanish moss, fibers and other materials. In the season between June to December, when the birds are not procreating, they usually travel in flocks to forage trees with fruit.
The idiosyncratic song of the male Oropendola is made of a sort of gurgling sound which is abruptly followed by whooping gooooo-FRRRRRRTTTT.
Botflies and brood paratism by Giant Cowbirds challenge the brood of the Chestnut-headed Oropendola, and nestling mortality is directly linked to these two factors. Oropendolas will often build their nests near bees and wasps who defend against the botflies, but do not attack the birds. The Cowbird chicks also help to protect Oropendola chicks to some degree.
Locations in Costa Rica: La Selva Biological Station, Monteverde Cloud Forest Reserve, Corcovado National Park, Peñas Blancas National Park
Diet: fruit, nectar, small amphibians, small reptiles
Migration Pattern: non-migratory
Habitat: oastal lowland forest
Size: length=28-35 cm weight=125-225 g (females are smaller than males)
Species: Psarocolius wagleri