The Scarlet Ibis is one of the most vividly coloured birds on Earth, an unmistakable crimson wader that gathers in dense flocks across the coastal wetlands, mangroves and mudflats of northern South America and Trinidad. Adults glow a saturated red from bill tip to tail, broken only by glossy black wingtips, a colour that comes entirely from the carotenoid pigments in the crustaceans they eat.
It is a highly social species, roosting and nesting in large mixed colonies and often flying in long lines or V formations at dawn and dusk. The Scarlet Ibis is the national bird of Trinidad and Tobago, where evening flights of thousands returning to roost at the Caroni Swamp are a famous spectacle. It is closely related to the White Ibis and the two sometimes interbreed where their ranges meet.
An adult Scarlet Ibis is almost impossible to confuse with anything else in its range. The entire body is a brilliant scarlet, the long legs and slender down-curved bill flush pinkish to reddish, and only the outermost wingtips are jet black. Young birds look very different, being a mix of grey, brown and white that reddens gradually over two years as they mature.
| Plumage | Adults uniformly brilliant scarlet with black wingtips; juveniles grey-brown above and white below |
| Bill | Long, slender and strongly down-curved, pinkish to reddish in adults |
| Legs | Long, reddish-pink, trailing well beyond the tail in flight |
| Size | 56 to 61 cm long, medium-sized for an ibis |
| Flight | Neck outstretched, flies in lines or V formations, alternating flaps and glides |
| Sexes | Alike in colour; males slightly larger with longer bills |
The Scarlet Ibis is a fairly quiet bird but not silent. At colonies and roosts it gives low grunts, soft croaks and squealing notes, and young birds beg with a wheezing call. Most vocal activity happens around the nest and at communal roosts, where the combined murmur of a large flock can be surprisingly loud.
It is found across northern South America, from Colombia and Venezuela through the Guianas and coastal Brazil, as well as on Trinidad and locally in parts of the Caribbean and Central America. The species favours coastal habitats including mangrove swamps, tidal mudflats, shallow lagoons, estuaries and flooded grasslands, where it probes soft mud for food. Some populations move seasonally in response to water levels.
The diet is dominated by crustaceans, especially small crabs and shrimp, which supply the carotenoids that give the bird its red colour. It also takes aquatic insects, molluscs, small fish and other invertebrates, feeding by probing and sweeping its sensitive curved bill through soft mud and shallow water, often in the company of other wading birds.
Scarlet Ibises nest colonially in trees and shrubs over or near water, frequently in mangroves and often alongside egrets, herons and other ibises. The nest is a simple platform of sticks in which the female lays three to five eggs. Both parents incubate for around three weeks and share feeding of the young, which fledge after several weeks but keep their dull immature plumage for a year or more.
- American White Ibis: Same body shape and red bill but white plumage; closely related and sometimes hybridises with the Scarlet Ibis
- Roseate Spoonbill: Also pink and found in similar wetlands, but has a broad flattened spoon-shaped bill rather than a curved one
- Glossy Ibis: Shares the slim down-curved bill and colonial habits but is dark chestnut and green rather than scarlet
Why is the Scarlet Ibis so red?
Its colour comes from carotenoid pigments in the crustaceans it eats, particularly crabs and shrimp. Birds that do not get enough of these pigments fade to a paler orange, which is why captive individuals sometimes lose their brilliance without a proper diet.
Is the Scarlet Ibis endangered?
No. It is listed as Least Concern by the IUCN and remains widespread and locally abundant. It is legally protected in several countries, including Trinidad and Tobago, where hunting and habitat loss remain local concerns.
Where is the best place to see Scarlet Ibis?
The Caroni Swamp in Trinidad is world famous for its evening flights, when thousands of ibises stream in to roost. They are also common in the coastal wetlands of Venezuela, the Guianas and northern Brazil.
Are Scarlet Ibis and White Ibis the same species?
They are very closely related and some authorities have treated them as one species because they interbreed where their ranges overlap. Most classifications keep them separate as the Scarlet Ibis and the American White Ibis.