Black-Crowned Night Heron
Here you have a Black-Crowned Night Heron, Nycticorax nycticorax. The rather repetitive scientific name means 'night raven night raven. There are two species in the genus, the Rufous Night Heron being Nycticorax caledonicus. That one is only found in Australasia, while the black-crowned is incredibly widely distributed, occurring in North and South America, Africa, Asia and Europe (where they used to be considered a delicacy). It is only absent in very cold and/or very dry regions. It is not only the most widespread heron species in the world, it might well also be the most numerous. These herons occur in swamps, marshes and riverside, lakeside and seaside habitats. In the northern countries, it only occurs in summer, flying south to warmer climes in the winter.
Here in South Africa, this heron is common though not frequently seen. It tends to be rather unobtrusive. By day, it usually roosts well-hidden amidst leaves in waterside trees. It often occurs in groups. When well seen, this species is easily identified. Like other herons, it has a very long neck, but typically doesn't show it, retracting its head to between its shoulders, the smooth contours of its feathers making it look practically neckless. It has elegant black, white and grey plumage, with a not-often-seen pair of long, wispy white feathers growing from its nape. Immatures are rather different-looking, scruffy in appearance with heavy black-and-brown streaking, but in shape and size similar to the adults. It is small for a heron, reaching a (stretched-out) length of 56 cm/22". Silent most of the time, it sometimes emits a hoarse croak when flushed out of hiding. But in their nesting colonies these birds are noisy, communicating and squabbling with each other with 'quok' and 'wok'-sounds. (It is called a 'quark' in the Falkland Islands, and has similarly onomatopoeic names in a number of other languages.)
Night herons, as the name indicates, are mostly active at night. They have large eyes and excellent night vision. Night herons hunt either singly or in small groups, starting at dusk. Like other herons and egrets, they are ambush predators. A heron will stand by the waterside, or perch on a branch or a stump, intensely eyeing the water for any sign of an edible little critter. Once having spotted something promising, it will rapidly shoot out its neck and grab it in its bill. This species, like the green-backed heron, sometimes uses a lure to attract fish. This can be a feather, a leaf, or a bit of bread nicked from picnickers. The heron drops this on the water surface and then patiently waits for something aquatic to come and investigate.
Like other herons and egrets, night herons build flimsy stick platforms for nests. They situate these low in trees or sometimes on the ground in dense reedbeds, or on small islands surrounded by water. The female lays two to four eggs (in South Africa, elsewhere 3 to 8). Both sexes incubate, and the eggs hatch in about three weeks. The voracious youngsters are fed by the adults shoving fish and other titbits into their gaping mouths. They leave the nest at age three weeks but only learn to fly at the age of six to seven weeks.
Apart from the Nycticorax night herons, there are two other genera which are very similar and are also called night herons. Gorsachius contains a number of species in Africa and Asia, while Nyctanassa is found in the Americas. Not long ago, several more species of night heron were living on a number of islands, from Ascension island in the Atlantic, through the Mascarene Islands in the Indian Ocean, to islands of the Pacific. Like other island species, these were likely not good fliers, and also lacking an instinctive fear of humans. All of them were driven to extinction shortly after humans colonized their islands.