The Sunbittern, Eurypyga helias, is a unique and solitary bird, the only representative of its family, Eurypygidae. It exhibits a rather subdued plumage of black, grey, and brown, with strikingly patterned wings that reveal vivid eyespots of red, yellow, and black when spread. These eyespots are not merely for beauty; they play a crucial role in the bird's behavior, being used in courtship, threat displays, and to startle predators.
Adult Sunbitterns can be distinguished by subtle variations in the feather patterns on their throat and head. They possess a long, pointed bill, black on the upper side, and a short hallux, similar to shorebirds and rails. The upperparts of the South American subspecies are predominantly brown, while the legs and lower mandible are a striking orange-yellow. The other subspecies are greyer above, with legs and bill sometimes showing a redder hue.
The Sunbittern is a denizen of humid Neotropical forests, favoring areas with open understories and in close proximity to water bodies such as rivers, streams, ponds, or lagoons.
This species ranges from Guatemala to Brazil. The nominate race, E. h. helias, inhabits the lowland tropical regions of South America, including the Orinoco and Amazon basins and the Pantanal. The E. h. meridionalis subspecies is found along the East Andean slope in south-central Peru, while E. h. major ranges from southern Guatemala through Central America and the Chocó to western Ecuador.
Sunbitterns are cryptic and elusive, often revealing their presence only when they display their large, eye-patterned wings in response to a threat. This behavior serves as a defense mechanism, startling potential predators.
A versatile predator, the Sunbittern feeds on a variety of animal prey, including insects, crabs, spiders, shrimps, earthworms, fish, tadpoles, toads, frogs, eels, and lizards. Remarkably, it has been observed using bait or lures to attract prey within striking distance, a behavior that is considered a form of tool use.
The breeding season commences with the onset of the wet season. Sunbitterns engage in aerial displays high in the forest canopy before nesting. They construct open nests in trees and lay two eggs adorned with blotched markings. The precocial chicks remain in the nest for several weeks post-hatching.
Due to its unique appearance and behaviors, the Sunbittern has few similar species within its range. However, its bittern-like stature may cause initial confusion with members of the heron family.
The Sunbittern is currently listed as Least Concern by the IUCN, indicating that it does not face any immediate threat of extinction in the wild.