Tricoloured Heron - Egretta tricolor

Tricoloured Heron

Egretta tricolor

Order : Ciconiiformes

Family : Ardeidae ;

Biometrics :

Size : 63 à 68 cm
Wingspan : 95 à 105 cm
Weight : M: 415gr- F: 335gr

Longevity : 17 years

IUCN conservation status :

Extinct

Threatened

Least
concern

Extinc
in the Wild

Near
threatened

Not
evaluated

EX EW CR EN VU NT LC NE

Geographic range :

Synonyms : Garceta Tricolor (es), Airone della Luisiana (it), Dreifarbenreiher (al), Witbuikreiger (nl), Tricoloured Heron (en)

Physical description :
Tricoloured heron is a medium-sized heron, with long and very slender neck and bill, and relatively short legs. Legs are yellow in winter, and pink in the breeding season. It has a long and pointed bill that is yellow in winter, with a black tip. But the yellow turns to blue in the breeding season.
Tricoloured heron has a combination of white belly and white stripe down centre of foreneck, contrasting with dark remainder of plumage. In flight, it shows white underwing coverts.
Adult winter lacks white hind crown feathers, and has shorter scapular plumes.
Juvenile differs in rufous sides to head, rufous neck (with white strike down foreneck, and lesser upperwings, and pale brown scapular feathers.

Voice : Tricoloured heron is usually silent away from breeding colonies. But it gives a harsh, nasal croak when flushed. Common call is a loud and sharp 'kyowk'.

Habitat : Tricoloured heron lives in shallow marshes and shores, mudflats, mangroves, swamps and bays, with woodland cover, because it often perches in trees.
GEOGRAPHIC RANGE: tricoloured heron is found in eastern and southern North America (coasts of Maine, through Texas, and coasts of Mexico), and Central America, in coastal areas. The West Indies and coastal South America to the mouth of the Amazon River in Brazil on Atlantic coast, and to northern Peru on the Pacific coast.

Behaviour : Tricoloured herons are migratory birds. It's usually solitary. It's very defensive about its hunting area, and it charges at other invading, Tricoloured Heron and other wading species.
To feed, it usually stands in shallow water, to find and catch prey. The most frequent form of prey catching behaviour is walking quickly, running with open wings and tactile sequence. Its behaviour is varied, depending on the habitat, but almost all the food is found in shallow water. Also runs rapidly through shallows, wings partly raised, with sometimes one foot far forward and vibrates foot rapidly along bottom to flush prey.
Tricoloured heron prefers to change its foraging and feeding strategies, in order to continue to eat its preferred preys.
The pair builds its nest when the water has receded. Low water levels help to concentrate prey in a small area, making it simpler for parent's birds to feed nestlings. Parents do not have to go far.

Flight : In flight, tricoloured heron holds its neck at a curve, similar to an 'S'.

Reproduction-nesting : The nest territory is selected by the tricoloured heron male. The nest is a platform of sticks and twigs, with a shallow central depression, lined with leaves and grasses. It's placed in a tree or on a bed of reeds. Male and female build the nest. They only raise one brood per year.
Female lays 3 to 4 bluish coloured eggs. Both parents incubate the eggs. The chicks hatch in about three weeks, several days apart from one another. Both adults care for the chicks and feed them regurgitated food.
The chicks fledge when they are 35 days old, and they go off on their own.

Food habits : 90% of the diet of tricoloured heron is composed of fish, but it also eats amphibians, crustaceans, gastropods, leeches, worms, spiders and insects.

Protection / threats : Nest success can be greatly compromised by cold weather, predation, and water levels that have not receded.
Raccoons, crows and ravens eat eggs and nestlings. Owls feed on adult as well as young.
Populations of tricoloured heron seem to have remained stable or increased in all of their habitats in the United States, except for Texas and southern Florida. Tricoloured heron has relatively large populations in North America, compared to other heron species.

Other links :
Iucn
Birdlife

Specification sheet created by Nicole Bouglouan

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