Giant heron
The Goliath heron (Ardea goliath is a very large wading bird of the heron family, Ardeidae. This is the world's largest living heron (the extinct Bennu heron was larger). The closest extant relatives of the Goliath are considered to be the Great-billed and the White-bellied herons of Southern Asia. Due to their large size, this species trio is sometimes referred to as the "giant herons”.
In flight the Goliath heron has a slow and rather ponderous look and, unlike some other herons, its legs are not held horizontally. Male and female look similar, with an overall covering of slate gray and chestnut feathers. The head and its bushy crest, face, back and sides of the neck are chestnut. The chin, throat, foreneck, and upper breast are white, with black streaks across the foreneck and upper breast. The lower breast and belly are buff with black streaks. The back and upper wings are slate grey, with a chestnut shoulder patch at the bend of the wings when they're closed. The under-wing is pale chestnut. The upper mandible is black and the lores and orbital areas are yellow with a greenish tinge. The eyes are yellow while the legs and feet are black. Juveniles look similar to adults but are paler. The only heron with somewhat similarly colorful plumage characteristics, the widespread purple heron, is much smaller than the Goliath.
Goliath herons are found in sub-Saharan Africa, with smaller numbers in Southwest and South Asia. They are very aquatic, even by heron standards, rarely venturing far from a water source; they even prefer to fly along waterways rather than move over land. They inhabit lakes, swamps, mangrove wetlands, reefs with few cool water, and sometimes river deltas. They are usually found in shallows, though can be observed near deep water over dense water vegetation. Goliath herons can even be found in small watering holes. They prefer pristine wetlands and generally avoid areas disturbed by humans.
Goliath herons are diurnal and solitary foragers. They are highly territorial towards other Goliaths entering their feeding territories. On occasions, two may be seen together but these are most likely to be a breeding pair or immatures. These herons are rather inactive feeders and often hunt by standing in the shallows, intently watching the water at their feet. This is a typical feeding method and they can forage in deeper waters due to their large size. They may also perch on heavy floating vegetation, in order to prevent water from rippling around them. As prey appears, the heron rapidly spears it with open mandibles, often spearing both mandibles through the fish's body, and then swallows it whole. It is possible that the bill is used in a lure-like fashion occasionally, attracting fish to the immobile, large object submerged in the water. The handling period is long, with herons often placing their struggling prey on floating vegetation while preparing to swallow it. Due to its generally slow movements and handling time, the Goliath is frequently vulnerable to kleptoparasitism. In Africa, African fish eagles frequently steal food caught by Goliaths, although other large birds such as Saddle-billed storks and pelicans may also steal their prey. Goliath herons have a distinct deep bark, often described as ‘kowoork’, audible from a distance of up to 2 km (1.2 miles). A disturbance call (arrk), sharper and higher, can also occasionally be heard. A ‘huh-huh’ is given during the crouched stage, while a ‘kooo’ may be heard with the neck extended.
Goliath herons are carnivores (piscivores) and prey almost entirely on fish. They specialize in relatively large fish, with an average prey weight range of 50-980 g (0.11-2.16 lb), averaging 500-600 g (1.1-1.3 lb), and a length of 30 cm (12 in). Small fish are generally ignored and the average Goliath catches around 2 or 3 fish a day. Breams, mullet, tilapia, and carp have locally been recorded as preferred species. Any other small animals that they come across may be eaten, including frogs, prawns, small mammals, lizards, snakes, insects, and even carrion.
Goliath herons are monogamous and form pairs. Their breeding season coincides generally with the start of the rainy season, which is around November to March. In some areas, breeding is year-round, with no discernable peak season. Breeding may not occur every year. Goliath herons prefer to nest on islands or islands of vegetation and may abandon a nesting site if the island becomes attached to the mainland. Lakes or other large bodies of water usually hold colonies. They nest fairly low in various sedges, reeds, bushes, trees, or even on rocks or large tree stumps. Pairs may nest solitary or in fairly large colonies. Occasionally, they may join mixed-species colonies including other heron species, cormorants, darters, ibises, and gulls. The nests are large but often flimsy, often measuring around 1 to 1.5 m (3.3 to 4.9 ft) in diameter. The female lays 2 to 5 (usually 3 or 4) pale blue eggs. Incubation lasts 24 to 30 days. Altricial (helpless) young are fed by regurgitation in the nest and, after a few weeks, can bill jab and practice defensive postures against each other. At around 5 weeks they leave the nest completely. The parents continue to tend to them for 40 to 80 days more.
There are no major threats to Goliath herons, however, they may suffer from the use of pesticides.
According to the IUCN Red List, the total population size of the Goliath heron is 6,700-67,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
