The night herons are medium-sized herons have a near-global distribution. These herons are migratory outside the tropical parts of their ranges.
In Europe, Night Heron is often used to refer to the Black-crowned Night Heron, since it is the only member of the genus in that continent.
The genus name Nycticorax derives from the Greek for “night raven” and refers to the largely nocturnal feeding habits of this group of birds, and the croaking crow-like call of the best known species, the Black-crowned Night Heron.
Their nocturnal habits may have their origin in these birds wishing to minimize competition for food with other water birds; or to avoid harassments from other birds that are aware of the night herons' habits of feeding on their eggs and young, and have, therefore, learned to attack night herons on sight.
Adults are short-necked and stout herons with short legs.
The plumage is usually either white or grey, except for a dark crown and back.
Juveniles are brown, flecked with white and grey, with their eyes open.
Breeding / Nesting:
Night herons usually nest in colonies on platforms of sticks in a group of trees, or on the ground in protected locations, such as islands or reedbeds.
A clutch consists of 3 - 8 eggs, which are incubated by both parents who take turns brooding them.
Diet / Feeding:
Night Herons primarily feed on small fish. However, these opportunistic feeders will also take frogs, aquatic and terrestrial insects, leeches, earthworms, crayfish, mussels, squid, reptiles (lizards, snakes), small mammals (rodents), plants, and even carrion and garbage at landfills. They will also take the eggs and nestlings of colonial-nesting waterbirds, such as terns, herons and ibises, and hunt small birds.
Most feeding occurs in shallow waters, where they grasps their prey with their bills, rather than stabbing them as other water birds tend to do. One of the techniques they utilize to attract prey is referred to as "bill vibrating" - they will open and close the bill rapidly in water, which creates a disturbance that lures prey. They may also stand motionless in water for long periods, with their necks tucked in a hunched posture until prey comes within range before striking out to catch them. When hunting, they also jump on water feet first or plunge from the air to catch prey.
They may walk about or swim in search of food. They shake their prey vigorously until stunned or killed and then they swallow them head first. The strong digestive acids in their stomachs can easily dissolve bones.
Most feeding is done early morning and at dusk, when all other herons are asleep thus avoiding competition with waterbirds sharing the same habitat. However, when food is scarce, competition high, during the breeding season, or whenever special opportunities afford themselves, they may also hunt during the day.
They are usually solitary forager and aggressively defend their feeding territories; and typically use the same feeding sites repeatedly.
- Yellow-crowned Night Heron, Nycticorax violaceus or Nyctanassa violacea
- Bermuda Night Neron, Nycticorax carcinocatactes or Nyctanassa carcinocatactes (extinct)
- Black-crowned Night Heron, Nycticorax nycticorax
- White-backed Night Heron, Nycticorax leuconotus or Gorsachius leuconotus
- Rodrigues Night Heron, Nycticorax megacephalus (extinct)
- Réunion Night Heron, Nycticorax duboisi (extinct)
- Mauritius Night Heron, Nycticorax mauritianus (extinct)
- Ascension Night Heron, Nycticorax olsoni (extinct)
- Niue Night Heron, Nycticorax kalavikai (prehistoric)
- ‘Eua Night Heron, Nycticorax sp. (prehistoric)
- Lifuka Night Heron, Nycticorax sp. (prehistoric) - may be same as ‘Eua species
- Nankeen Night Heron or Rufous Night Heron, Gorsachius caledonicus or Nycticorax caledonicus
- White-eared Night Heron, Gorsachius magnificus
- Japanese Night Heron, Gorsachius goisagi
- Malayan Night Heron, Gorsachius melanolophus
Species Research by Sibylle Johnson