© Shutterstock.com/Martin Mecnarowski. A scarlet ibis roost in mangrove trees near Caroni Swamp in Trinidad. Such gatherings are among the world’s most memorable bird spectacles
AT COLCHESTER Zoo in Essex, I once heard a mother confidently telling her son that the scarlet ibis perching on a branch was a flamingo. It was perhaps a fairly easy mistake to make because there are few birds with such intensely coloured plumage. However, the scarlet ibis is much more resolutely scarlet than any flamingo and you do not, of course, expect to see flamingos perched in trees.
Scarlet ibis are also much smaller than flamingos at about 70cm (28in) tall and have a very long, downwards-curving bill like that of other ibis, which is used to probe for food in shallow, muddy waters. The male is larger than the female but the sexes are otherwise similar. The usual call is a loud honk.
Scarlet ibis are outstanding among the ibis family for the intensity of their feather colour. The specific part of their scientific name Eudocimus ruber means red, which scarcely does justice to the real flame-like scarlet of the plumage. One of the great wildlife experiences of the world is to see large flocks of scarlet ibis coming in to roost among the mangroves in the heart of Caroni Swamp. This is their main home in Trinidad where they are the national bird. They can also be found along the coasts of northern South America and occasionally in Central America. Birds have been introduced to the southern USA.
Juveniles are duller in colour with light brown or off-white feathers. The scarlet colour develops as the birds mature, due to accumulations of the pigments from the crustaceans in their diet. Captive-reared birds need to be fed a special diet based on a flamingo feed in order to maintain the richly coloured plumage. Beetroot and carrot supplements may be given to ensure colour saturation.
Other foods taken in the wild include small fish, frogs and reptiles. Some plant matter, such as soft fruit, is also consumed and insects, particularly ground and scarab beetles, form part of the diet.
Wild birds live in breeding colonies which can reach thousands of individuals. They build fairly scruffy nests of sticks high in trees and tend to prefer islands less accessible to predators. Males may have more than one partner. The female lays one to three eggs, which are pale bluish-green with brown markings. Both parents guard the nest. The incubation period is roughly 23 days.
Chicks are helpless on hatching and require support to feed on regurgitated food. There is a very high mortality rate and up to half of chicks may not live to fledge. Those that survive grow quickly and usually fledge at 35 days. They will be independent after about 75 days.
In the wild, scarlet ibis can live up to 15 years but in captivity the upper limit is more like 20 years. The oldest captive individual on record lived for 31 years.
Gail Harland lives in Norfolk with her family and a variety of birds.
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