Yellow-crowned Night-Heron - Nyctanassa violacea

Yellow-crowned Night-Heron

Nyctanassa violacea

Order : Ciconiiformes

Family : Ardeidae ;

Biometrics :

Size : 55 à 61 cm
Wingspan : 107 à 112 cm
Weight : 650 à 750 gr

Longevity : 6 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 : Gulkronad natthäger (sv), Martinete Coronado (es), Nitticora violacea (it), Krabbenreiher (al), Geelkruinkwak (nl), Yellow-crowned Night-Heron (en)

Physical description :
Yellow-crowned Night Heron has blue grey body plumage. Head pattern is black and white. Adult has black head with creamy to buff crown and forehead, and broad white auricular stripe. In breeding plumage, we can see 2 to 6 elongated, black and white occipital feathers. It has broad pointed wings and squared tail.
Neck and underparts are pale grey. Upperparts are blue grey with dark brown feathers, with pale edges. Flight feathers are blackish, and it has grey under wings.
Yellow-crowned Night Heron has thick and heavy blackish bill, sometimes greenish yellow below at base. Lores are greyish yellow. Eyes are amber to red in adults. Legs are yellow, becoming pinkish red in breeding plumage.
Both sexes are similar, with female somewhat smaller.
Juvenile has greyish plumage, finely spotted with buff on upperparts. Eyes are paler than adults, yellow to amber. Legs are greenish yellow. Juvenile reaches adult plumage at about two years of age.

Voice : Yellow-crowned Night Heron utters guttural gruff barking 'kwehk' or 'kyowk'. Its call is higher and more nasal than Black-crowned Night Heron. We can also hear loud 'quawk'. It is often silent at night.

Habitat : Yellow-crowned Night Heron lives in mangroves and coastal areas. It is found in open beaches, but also in freshwater marshes and wooded swamps and thickets.
GEOGRAPHIC RANGE: Yellow-crowned Nigh Heron breeds along Atlantic coasts, from New York southwards to Kansas and Indiana, and also southwards to South America, to southern Brazil and on Pacific coast to Peru.
It winters along Atlantic and Gulf coasts, to South Carolina. But in warmer location, birds are resident.

Behaviour : Yellow-crowned Night Heron is mainly nocturnal, but sometimes it searches for food among roots of mangroves at all hours of the day. It follows the riversides and captures both aquatic and terrestrial animals. It searches for prey in tidal creeks and tide pools, wading in shallow water, or standing and waiting for food. It walks with elegance, slowly, picking prey up from the ground, appearing to do it with little concern. After feeding, it rests in the middle of an island, standing in a crouching posture.
Yellow-crowned Night Heron defends itself strongly, with its claws and the bill. It is a solitary bird, and it may nest singly or in loose colonies. It is monogamous.
Courtship displays include circle flights used in territorial defence.

Flight : Yellow-crowned Night Heron flies with slow wing beats. Legs and feet are projected behind body. Its flight is rather slow. If alarmed, it may rise almost perpendicularly, and then, take a direction. It has graceful, direct and strong flight, with deep steady wing beats.

Reproduction-nesting : Yellow-crowned Night Heron nests in trees, but sometimes on the ground. This species nests in colonies, located in dense vegetation. They avoid areas with insufficient cover. When they nest in low vegetation, they nest closer to the ground, and in groups with other herons. Nest may be located at about 8 feet, but also in trees from 8 to 25 feet.
Nest is a platform made with dry sticks, in loose manner, and also with some weeds and a scanty lining of fibrous roots.
Female lays 2 to 4 pale blue green eggs. Incubation lasts about 21 to 25 days, by both parents. Chicks are fed by both parents, with regurgitated food on the first days.
Young remain at nest until they are able to fly (about 25 days), but they leave it to follow adults along shores. They may climb on branches to hide if threatened.
This species produces one brood per season, sometimes two.

Food habits : Yellow-crowned Night Heron feeds mainly on crustaceans, but also fish, amphibians, aquatic insects, snails, and sometimes small snakes. It may eat young birds fallen from the nest.

Protection / threats : Yellow-crowned Night Heron has been heavily killed for its feathers until 1910. This species began to breed in 1927, and during several decades, levelling during mid 1950s and 1960s.
Suitable habitat is regularly destroyed since latter half of 20th century, and populations are threatened by habitat loss.
Declines have occurred in several states, and the species is now listened as endangered, threatened, or of special concern.

Other links :
Iucn
Birdlife

Specification sheet created by Nicole Bouglouan

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