|Size:||Height: 23 to 28 inches (58 to 71 cm) Wingspan: 45 inches (114 cm)|
|Weight:||21 to 30 ounces (595 to 850 g)|
|Diet:||Fish, frogs, small birds and mammals, leeches, vegetation, snakes, lizards and crayfish|
|Distribution:||North America, South America, Eurasia and Africa|
|Young:||3 to 5 chicks, once a year|
|IUCN Status:||No special status|
· There are 22 species of herons in the Americas.
· The call of the black-crowned night heron sounds like “kwack” or “kwark.”
· The species name is Greek, meaning nyctos (night) and corax (crow).
· This heron is called a “kwak” in Dutch because of its call.
· Black-crowned night herons can fly up to 35 miles (56 km) per hour.
Black-crowned night herons are stocky, short-necked birds with short legs in comparison to most other herons. They have black on the top of their head and back, grey wings, a long black bill and a white face and underbelly. They also have long white plumes extending from the black crest on their head. Their legs are usually green, but may turn pink or red during breeding season. Females are similar in colour to males, but tend to be slightly smaller.
Black-crowned night herons can be found throughout South America, Central America and North America, including Hawaii, and up to southern Canada. They are also found in Africa, mostly south of the Sahara desert, but also along the northern east coast. In Europe they exist south of Scandinavia (with the exception of Great Britain), and in western Asia. Black-crowned night herons mainly inhabit wetlands such as swamps, ponds, streams, rivers and marshes, especially those with overgrown areas including plants such as bulrushes. They nest in colonies among reeds in marshes or ponds, or high up in a tree nearby a marshy area.
Although they are social birds, black-crowned night herons hunt alone, eating fish, frogs, small mammals, leeches, vegetation, snakes, lizards and crayfish. They have extremely strong digestive stomach acids that are capable of dissolving bones.
Black-crowned night herons are monogamous. The male tries to impress females by performing a courting ritual during which he walks in a crouched position with his head lowered and stretches his neck out while making a snapping noise. When a male and female decide to form a pair, their legs turn pink. They appear to be very affectionate with each other, nibbling each other’s feathers and rubbing their bills together. Mating takes place only after the pair is established and they have built a nest together. The male collects materials for the nest such as twigs, roots and grass, and passes them to the female, who incorporates them into the nest. Once they have all the materials they need, the male helps the female put the finishing touches on their new home. Eggs are laid two days apart, four to five days after mating. Both parents take turns sitting on the eggs, which hatch in 24 to 26 days. The eggs are green when first laid, and gradually fade to pale green-blue. Two weeks after they hatch, the chicks may begin to leave the nest to go out and explore. They can fly well by the time they are seven weeks old, at which time they leave the nest for good. By the time they are three years of age they acquire full adult plumage. When disturbed by predators, juvenile black-crowned night herons may regurgitate food or defecate down on them from their tree perch.
Black-crowned night herons are noisy, social birds that congregate with many other species of herons. They are active during the night and roost during the day. They migrate south during early spring and return in late summer/autumn.
Black-crowned night heron populations diminished in the 1960s due to the use of the pesticide DDT. Habitat destruction has also become a serious problem. Black-crowned night herons are a “State Endangered” species in Illinois and Kentucky, and a “State Threatened” species in Tennessee.
Black-Crowned Night Heron Wildlife Fact File, IM Pub, US
Harrison, C. and Greensmith, A. (1993). Birds of the World. London: Dorling Kindersley Limited