The Goliath heron (Ardea goliath), also known as the giant heron, is a very large wading bird of the heron family, Ardeidae. It is found in sub-Saharan Africa, with smaller, declining numbers in Southwest and South Asia.
This is the world's largest living heron (the extinct Bennu heron was larger). The height of the goliath heron is 120–152 cm (3 ft 11 in – 5 ft 0 in), the wingspan is 185–230 cm (6 ft 1 in – 7 ft 7 in) and the weight is 4–5 kg (8.8–11.0 lb).[4][5] The tarsus measures from 21.2 to 25.5 cm (8.3 to 10.0 in) and the wing chord averages around 60.7 cm (23.9 in) in length. The culmen measures from 18 to 20 cm (7.1 to 7.9 in), while the bill from the gape measures around 24 cm (9.4 in). In flight it has a slow and rather ponderous look and, unlike some other herons, its legs are not held horizontally.
The Goliath heron is very aquatic, even by heron standards, rarely venturing far from a water source and preferring to fly along waterways rather than move over land. Important habitats can include lakes, swamps, mangrove wetlands, reefs with few cool water, sometimes river deltas. It typically is 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 have ranged in elevation from sea level to 2,100 m (6,900 ft). They tend to prefer pristine wetlands and generally avoid areas where human disturbances are a regular occurrence.
Goliath herons are solitary foragers and 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. A diurnal and often rather inactive feeder, this heron often hunts by standing in the shallows, intently watching the water at its feet. This is a typical feeding method among large Ardea herons and it can forage in deeper waters than most due to its larger size. It 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 pirate food caught by Goliaths, although other large birds such as saddle-billed storks and pelicans may also steal their prey.
Prey almost entirely consists of fish. The Goliath heron specializes 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 length of 30 cm (12 in). Fish exceeding 1 kg (2.2 lb) are usually rejected, though there is a report that the heron managed to swallow 1.4 kg (3.1 lb) fish. 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.
Its breeding season coincides generally with the start of the rainy season, which is around November to March. In some areas, breeding is year around, with no discernable peak season. Breeding may not occur every year. Fairly adaptable in their nesting site selection, Goliath herons generally prefer to nest on islands or islands of vegetation. The birds 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 variously sedge, reeds, bushes, trees or even on rocks or large tree stumps. The nesting dispersal seems highly variable as everything from a solitary pair (with no other Goliath nests anywhere near) to fairly large colonies have been observed, with no seeming local geographical preferences. Occasionally, they may join mixed-species colonies including other heron species, cormorants, darters, ibises and gulls. The breeding displays are not well known and may be subdued, due in part to breeding pairs possibly reunited year after year. The nests are large but often flimsy (depending on available vegetation around the nesting site), often measuring around 1 to 1.5 m (3.3 to 4.9 ft) in diameter.
