The range of Ardea goliath stretches throughout Africa, from Southern Egypt into South Africa. There are also populations reported in various patches of habitat in the Middle East and the Indian subcontinent.
Biogeographic Regions: oriental (Native ); ethiopian (Native )
Goliath herons have few natural predators due to their large size, watery habitat and ability to fly away from any ground- or water-dwelling predators. Some birds of prey, such as African fish eagles, may hunt juveniles or chicks, but as full-grown adults the risk of predation is low due to their large size.
Known Predators:
Ardea goliath is grayish-purple in color, with rufous or chestnut markings on its elongated neck, head and breast. It bears resemblance to its close relatives, purple herons (Ardea purpurea), but lacks distinctive black markings on its face and neck. It is also distinguished by its enormous size. At 1.5 m in length and 4.5 kg in mass, goliath herons are the largest of all living herons. They have a wingspan of 2 m.
Females are slightly smaller than males. Juveniles have more rufous, mottled breasts and bellies, and less distinct stripes.
In terms of systematics, goliath herons are most closely related to Sumatran herons (Ardea sumatrana) and white-bellied herons (Ardea insignis) of Southeast Asia.
Range mass: 4.3 to 4.5 kg.
Range length: 1.2 to 1.5 m.
Average wingspan: 2 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
One account of Ardea goliath reports a maximum age of 22.9 years in captivity. Similar birds in the wild reach around 15 years of age at the oldest.
Range lifespan
Status: captivity: 22.9 (high) years.
Ardea goliath lives in large rivers, lakes, estuaries, swamps, marshes, and other freshwater and shallow saltwater habitats. It prefers areas with large fish to support its feeding habits. It has been observed at elevations of up to 2100 m.
Range elevation: 2100 (high) m.
Habitat Regions: temperate ; tropical ; terrestrial ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools; coastal ; brackish water
Wetlands: marsh ; swamp
Other Habitat Features: riparian ; estuarine
Ardea goliath opportunistically feeds on a variety of prey items, from carrion to amphibians, but prefers fish.
Ardea goliath typically feeds upon large fish, employing what scientists call a “Jackpot” strategy: goliath herons seem to pass up numerous opportunities to eat smaller fish in a gamble to not disturb the water and thereby be able to catch large ones. According to a 1980 study on feeding ecology, the average size of prey caught was around 30 cm, with only very few catches of prey less than 15 cm in length.
Feeding ecology influences many aspects of the behavior of Ardea goliath. Goliath herons typically land directly on mats of vegetation when possible, to reduce disturbance to the water. Mats of vegetation also frequently attract fish by providing food, and reduce other disturbance in the water so that it may be easier for goliath herons to detect subtle commotion caused by large fish swimming nearby.
Animal Foods: mammals; amphibians; reptiles; fish; mollusks; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
Ardea goliath plays a role as a dominant predator of large fishes in the areas in which it lives, as it has few natural predators of its own. It is affected by many typical ectoparasites and endoparasites, including disease-causing viruses and bacteria, and digestive tract worms.
Commensal/Parasitic Species:
Many birders enjoy watching goliath herons because they are large, unique and beautiful. It can therefore contribute economically to areas where Ardea goliath naturally occurs via tourism and birding. In India, goliath herons were formerly considered a delicacy and a royal gamebird with similar taste to the pheasant. It is now practically never consumed, due to its reduced range and habitat in this region.
There are no known adverse effects of goliath herons on humans.
Ardea goliath has been evaluated by IUCN as Least Concern because of its vast range and relatively stable, large population. It could potentially be threatened by habitat destruction or hunting in the future, especially in areas of the Middle East and South Asia where populations are small and patchy; but currently the species is not considered a conservation priority. In areas where populations are smaller and sparser, conservation of nesting areas is crucial to ensure the survival of the species.
CITES: no special status
IUCN Red List of Threatened Species: least concern
Goliath herons use primarily loud squawks to communicate. They attempt to detect prey mainly with vision. Their squawks vary greatly and include, from a “Kowoork” under normal circumstances, an “Arrk” in response to a disturbance, a “Kroo” and “Huh-huh” during stretching, and an “organ-like dueting”. The dueting is thought to be important for communication between members of a mating pair at the nest. Their sense of smell is relatively undeveloped and not relied upon by goliath herons. Like all birds, goliath herons perceive their environment through visual, auditory, tactile and chemical stimuli.
Communication Channels: visual ; acoustic
Other Communication Modes: duets
Perception Channels: visual ; tactile ; acoustic ; chemical
Ardea goliath typically forms monogamous mating pairs, in which both parents together guard the nest and raise chicks.
Little is known about the mating rituals of goliath herons, as observations of the rituals are not reported in the literature. It is known that the plumage becomes brighter during mating season, and a special dueting song occurs during the mating season. It is thought that observations of mating rituals may be absent because the birds re-pair with the same mates year after year, and therefore have little need to win over a new mate with a ritual.
Mating System: monogamous
The breeding season and interval varies with location of individual populations of Ardea goliath. The breeding season most commonly occurs with the start of the rainy season. However, in some places, breeding occurs year-round; in others, such as South Africa, breeding occurs biannually or less frequently.
Nests are constructed of sticks and twigs. The nests are at least 1 meter in diameter, and are typically found on islands in low vegetation (below 3 meters). Goliath herons sometimes nest with other birds in mixed rookeries, and sometimes solitarily. There have been some reports of birds abandoning nest sites when islands became a part of the mainland, which raises conservation concern for Ardea goliath, as preserving nesting sites is imperative to ensuring the species’ future.
Goliath herons lay a clutch of 2 to 5 eggs. The young hatch after an incubation period of 24 to 30 days.
Breeding interval: Goliath herons generally breed once annually.
Breeding season: The breeding season for goliath herons typically coincides with the rainy season.
Range eggs per season: 2 to 5.
Average eggs per season: 3-4.
Range time to hatching: 24 to 30 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Like most birds, both parents of Ardea goliath play active roles in raising chicks up to fledging. A typical clutch includes three or four pale blue eggs, of which typically no more than one or two chicks survive. Chicks are born altricial, with downy feathers and eyes closed. After 25-30 days of incubation, chicks are fed twice-daily through regurgitation by the parents. After five weeks in the nest, chicks leave but are still cared for by their parents for an adjusting period of 40 to 80 days.
Sibling rivalry and siblicide is common in many birds, and goliath herons are no exception. Competition within the nest makes chick survival difficult, and only 1-2 birds reach independence out of each clutch of 2-5 eggs.
Parental Investment: altricial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Male, Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents; extended period of juvenile learning
Resident breeder.
The Goliath heron (Ardea goliath), also known as the giant heron,[2] 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).[3] 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).[6] In flight it 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. Despite the shared plumage characteristics with the purple species, 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".[7]
The Goliath heron has a distinct deep bark, often described as kowoork, audible from a distances of up to 2 km. A disturbance call (arrk), sharper and higher, can also occasionally be heard. A huh-huh is given during the crouched stage, while a krooo may be heard with the neck extended. Organ-like duetting has been reported at nest sites but has not been confirmed.
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.[8] 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.[7] 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.[9][10] 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.[7][9][10]
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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.
Eggs are pale blue, averaging 72 by 54 mm (2.8 by 2.1 in) and weighing around 108 g (3.8 oz). The clutch size can range from 2 to 5 (usually 3 or 4). Incubation lasts 24 to 30 days. Although they can sometimes replace clutches, often only around 25% of eggs succeed in hatching due to various environmental conditions or predation. The 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 five weeks they leave the nest completely. The parents continue to tend to them for variously 40 to 80 days. Around 62% of fledglings who successfully leave the nest survive to adulthood. Locally, the white-tailed eagle and the African fish eagle may be a predator in colonies. Despite their ponderous movements, Goliath herons can think quickly and often take flight before danger approaches. Also, due to its size and formidable bill, the full-grown Goliath heron may not have any regular predators.[7]
Ardea goliath egg 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.
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