Shoebill | |
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At the Pairi Daiza in Brugelette, Belgium | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Pelecaniformes |
Family: | Balaenicipitidae |
Genus: | Balaeniceps Gould, 1850 |
Species: | B. rex |
Binomial name | |
Balaeniceps rex Gould, 1850 | |
range |
The shoebill (Balaeniceps rex), also known as the whale-headed stork, and shoe-billed stork, is a large long-legged wading bird. It derives its name from its enormous shoe-shaped bill. It has a somewhat stork-like overall form and has previously been classified with the storks in the order Ciconiiformes based on this morphology. However, genetic evidence places it with pelicans and herons in the Pelecaniformes. The adult is mainly grey while the juveniles are more brown. It lives in tropical East Africa in large swamps from South Sudan to Zambia.
The shoebill may have been known to Ancient Egyptians [3] but was not classified until the 19th century, after skins and eventually live specimens were brought to Europe. John Gould very briefly described it in 1850 from the skin of a specimen collected on the upper White Nile by the English traveller Mansfield Parkyns. Gould provided a more detailed description in the following year. He placed the species in its own genus Balaeniceps and coined the binomial name Balaeniceps rex. [4] [5] [6] The genus name comes from the Latin words balaena "whale", and caput "head", abbreviated to -ceps in compound words. [7] Alternative common names are whalebill, [8] shoe-billed stork and whale-headed stork. [9]
Traditionally considered as allied with the storks (Ciconiiformes), it was retained there in the Sibley-Ahlquist taxonomy which lumped a massive number of unrelated taxa into their "Ciconiiformes". Based on osteological evidence, the suggestion of a pelecaniform affinity was made in 1957 by Patricia Cottam. [10] Microscopic analysis of eggshell structure by Konstantin Mikhailov in 1995 found that the eggshells of shoebills closely resembled those of other Pelecaniformes in having a covering of thick microglobular material over the crystalline shells. [11] In 2003, the shoebill was again suggested as closer to the pelicans (based on anatomical comparisons) [12] or the herons (based on biochemical evidence). [13] A 2008 DNA study reinforces their membership among the Pelecaniformes. [14]
So far, two fossilized relatives of the shoebill have been described: Goliathia from the Early Oligocene of Egypt and Paludiavis from the Late Miocene of Pakistan and Tunisia. [15] [16] [17] It has been suggested that the enigmatic African fossil bird Eremopezus have features resembling those of the shoebill and the secretary bird. [18]
The shoebill is a tall bird, with a typical height range of 110 to 140 cm (43 to 55 in) and some specimens reaching as much as 152 cm (60 in). Length from tail to beak can range from 100 to 140 cm (39 to 55 in) and wingspan is 230 to 260 cm (7 ft 7 in to 8 ft 6 in). Weight has reportedly ranged from 4 to 7 kg (8.8 to 15.4 lb). A male will weigh on average around 5.6 kg (12 lb) and is larger than a typical female of 4.9 kg (11 lb). [19] The signature feature of the species is its huge, bulbous bill, which is straw-coloured with erratic greyish markings. The exposed culmen (or the measurement along the top of the upper mandible) is 18.8 to 24 cm (7.4 to 9.4 in), the third longest bill among extant birds after pelicans and large storks, and can outrival the pelicans in bill circumference, especially if the bill is considered as the hard, bony keratin portion. [19] As in the pelicans, the upper mandible is strongly keeled, ending in a sharp nail. The dark coloured legs are fairly long, with a tarsus length of 21.7 to 25.5 cm (8.5 to 10.0 in). The shoebill's feet are exceptionally large, with the middle toe reaching 16.8 to 18.5 cm (6.6 to 7.3 in) in length, likely assisting the species in its ability to stand on aquatic vegetation while hunting. The neck is relatively shorter and thicker than other long-legged wading birds such as herons and cranes. The wings are broad, with a wing chord length of 58.8 to 78 cm (23.1 to 30.7 in), and well-adapted to soaring. [19]
The plumage of adult birds is blue-grey with darker slaty-grey flight feathers. The breast presents some elongated feathers, which have dark shafts. The juvenile has a similar plumage colour, but is a darker grey with a brown tinge. [9] When they are first born, shoebills have a more modestly-sized bill, which is initially silvery-grey. The bill becomes more noticeably large when the chicks are 23 days old and becomes well developed by 43 days. [19]
The shoebill is normally silent, but they perform bill-clattering displays at the nest. [9] When engaging in these displays, adult birds have also been noted to utter a cow-like moo as well as high-pitched whines. Both nestlings and adults engage in bill-clattering during the nesting season as a means of communication. When young are begging for food, they call out with a sound uncannily like human hiccups. In one case, a flying adult bird was heard uttering hoarse croaks, apparently as a sign of aggression at a nearby marabou stork (Leptoptilos crumeniferus). [19]
Its wings are held flat while soaring and, as in the pelicans and the storks of the genus Leptoptilos , the shoebill flies with its neck retracted. Its flapping rate, at an estimated 150 flaps per minute, is one of the slowest of any bird, with the exception of the larger stork species. The pattern is alternating flapping and gliding cycles of approximately seven seconds each, putting its gliding distance somewhere between the larger storks and the Andean condor (Vultur gryphus). When flushed, shoebills usually try to fly no more than 100 to 500 m (330 to 1,640 ft). [19] Long flights of the shoebill are rare, and only a few flights beyond its minimum foraging distance of 20 m (66 ft) have been recorded.
The shoebill is distributed in freshwater swamps of central tropical Africa, from southern Sudan and South Sudan through parts of eastern Congo, Rwanda, Uganda, western Tanzania and northern Zambia. The species is most numerous in the West Nile sub-region and South Sudan (especially the Sudd, a main stronghold for the species); it is also significant in wetlands of Uganda and western Tanzania. More isolated records have been reported of shoebills in Kenya, the Central African Republic, northern Cameroon, south-western Ethiopia, and Malawi. Vagrant strays to the Okavango Basin, Botswana and the upper Congo River have also been sighted. The distribution of this species seems to largely coincide with that of papyrus and lungfish. They are often found in areas of flood plain interspersed with undisturbed papyrus and reedbeds. When shoebill storks are in an area with deep water, a bed of floating vegetation is a requirement. They are also found where there is poorly oxygenated water. This causes the fish living in the water to surface for air more often, increasing the likelihood a shoebill stork will successfully capture it. [20] The shoebill is non-migratory with limited seasonal movements due to habitat changes, food availability and disturbance by humans. [19]
Petroglyphs from Oued Djerat, eastern Algeria, show that the shoebill occurred during the Early Holocene much more to the north, in the wetlands that covered the present-day Sahara Desert at that time. [21]
The shoebill occurs in extensive, dense freshwater marshes. Almost all wetlands that attract the species have undisturbed Cyperus papyrus and reed beds of Phragmites and Typha . Although their distribution largely seems to correspond with the distribution of papyrus in central Africa, the species seems to avoid pure papyrus swamps and is often attracted to areas with mixed vegetation. More rarely, the species has been seen foraging in rice fields and flooded plantations. [19]
The shoebill is noted for its slow movements and tendency to stay still for long periods, resulting in descriptions of the species as "statue-like". They are quite sensitive to human disturbance and may abandon their nests if flushed by humans. However, while foraging, if dense vegetation stands between it and humans, this wader can be fairly tame. The shoebill is often attracted to poorly oxygenated waters such as swamps, marshes, and bogs where fish frequently surface to breathe. They also seem to exhibit migratory behaviors based upon differences in the surface water level. Immature shoebills abandon nesting sites which increased in the surface water level whereas adult shoebills abandon nesting sites which decreased in surface water level. It is suggested that both adult and immature shoebills prefer nesting sites with similar surface water levels. [22] Exceptionally for a bird this large, the shoebill often stands and perches on floating vegetation, making them appear somewhat like a giant jacana, although the similarly sized and occasionally sympatric Goliath heron (Ardea goliath) is also known to stand on aquatic vegetation. Shoebills, being solitary, forage at 20 m (66 ft) or more from one another even where relatively densely populated. This species stalks its prey patiently, in a slow and lurking fashion. While hunting, the shoebill strides very slowly and is frequently motionless. Unlike some other large waders, this species hunts entirely using vision and is not known to engage in tactile hunting. When prey is spotted, it launches a quick violent strike. However, depending on the size of the prey, handling time after the strike can exceed 10 minutes. Around 60% of strikes yield prey. Frequently water and vegetation is snatched up during the strike and is spilled out from the edges of the mandibles. The activity of hippopotamus may inadvertently benefit the shoebill, as submerged hippos occasionally force fish to the surface. [19]
The solitary nature of shoebills extends to their breeding habits. Nests typically occur at less than three nests per square kilometre, unlike herons, cormorants, pelicans, and storks, which predominantly nest in colonies. The breeding pair of shoebills vigorously defends a territory of 2 to 4 km2 (0.77 to 1.54 sq mi) from conspecifics. In the extreme north and south of the species' range, nesting starts right after the rains end. In more central regions of the range, it may nest near the end of the wet season in order for the eggs to hatch around the beginning of the following wet season. Both parents engage in building the nest on a floating platform after clearing out an area of approximately 3 m (9.8 ft) across. The large, flattish nesting platform is often partially submerged in water and can be as much as 3 m (9.8 ft) deep. The nest itself is about 1 to 1.7 m (3.3 to 5.6 ft) wide. Both the nest and platform are made of aquatic vegetation. From one to three white eggs are laid. These eggs measure 80 to 90 mm (3.1 to 3.5 in) high by 56 to 61 mm (2.2 to 2.4 in) and weigh around 164 g (5.8 oz). Incubation lasts for approximately 30 days. Both parents actively brood, shade, guard and feed the nestling, though the females are perhaps slightly more attentive. Shoebills use their mandibles to cool their eggs with water during days with high temperatures around 30–33 °C (86–91 °F). They fill their mandible once, swallow the water, and fill another mandible full of water before proceeding back to their nest where they pour out the water and regurgitate the previously swallowed water onto both the nest and eggs. [23] Food items are regurgitated whole from the gullet straight into the bill of the young. Shoebills rarely raise more than one chick but will hatch more. The younger chicks usually die and are intended as "back-ups" in case the eldest chick dies or is weak. Fledging is reached at around 105 days and the young birds can fly well by 112 days. However, they are still fed for possibly a month or more after this. It will take the young shoebills three years before they become fully sexually mature. [19]
Shoebills are elusive when nesting, so cameras must be placed to observe them from afar to collect behavioral data. There is an advantage for birds that are early breeders, as the chicks are tended for a longer period. [24]
Shoebills are largely piscivorous but are assured predators of a considerable range of wetland vertebrates. Preferred prey species have reportedly included marbled lungfish (Protopterus aethiopicus), African lungfish (Protopterus annectens), and Senegal bichir (Polypterus senegalus), various Tilapia species and catfish, the latter mainly in the genus Clarias . Other prey eaten by this species has included frogs, water snakes, Nile monitors (Varanus niloticus) and baby crocodiles. More rarely, small turtles, snails, rodents, small waterfowl and carrion have reportedly been eaten. [25] [26] [27] [28]
Given its sharp-edged beak, huge bill, and wide gape, the shoebill can hunt large prey, often targeting prey bigger than is taken by other large wading birds. In the Bangweulu Swamps of Zambia, fish eaten by this species are commonly in the range of 15 to 50 cm (5.9 to 19.7 in). [29] The main prey items fed to young by the parents were the catfish Clarias gariepinus , (syn. C. mossambicus) and 50 to 60 cm (20 to 24 in) long water snakes. [27] In Uganda, lungfish and catfish were mainly fed to the young. [19] Larger lungfish and catfish were taken in Malagarasi wetlands in western Tanzania. During this study, fish around 60 to 80 cm (24 to 31 in) were quite frequently taken and the largest fish caught by the shoebill was 99 cm long. Fish exceeding 60 cm were usually cut into sections and swallowed at intervals. The entire process from scooping to swallowing ranged from 2 to 30 minutes depending on prey size. However, these large prey are relatively hard to handle and often targeted by African fish eagle (Icthyophaga vocifer), which frequently steal large wading bird's prey. [25]
This species is considered to be one of the five most desirable birds in Africa by birdwatchers. [30] They are docile with humans and show no threatening behavior. Researchers were able to observe a bird on its nest at a close distance – within 2 meters (6 ft 7 in). [31] Shoebills are often kept in zoos, but breeding is rarely reported. Shoebills have bred successfully at Pairi Daiza in Belgium and at Tampa's Lowry Park Zoo in Florida. [32] [23]
Beginning in 2014 and with various interspersed surges of attention since then, the shoebill has become the subject of internet memes, in part due to its intimidating appearance and its tendency to stand still for long periods of time. One such example is a video of a shoebill standing in the rain whilst staring into the camera. These memes have since also appeared on the social media platform TikTok, bringing a comparatively unknown species of bird into popular culture. [33] The shoebill also inspired the design of the Loftwing birds in the 2011 game The Legend of Zelda: Skyward Sword . [34] [35]
The population is estimated at between 5,000 and 8,000 individuals, the majority of which live in swamps in South Sudan, Uganda, eastern Democratic Republic of the Congo, and Zambia. [36] There is also a viable population in the Malagarasi wetlands in Tanzania. [37] BirdLife International has classified it as Vulnerable with the main threats being habitat destruction, disturbance and hunting. The bird is listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). [38] Habitat destruction and degradation, hunting, disturbance and illegal capture are all contributing factors to the decline of this species. Agriculture cultivation and pasture for cattle have also caused significant habitat loss. Indigenous communities that surround Shoebill habitats capture their eggs and chicks for human consumption and for trade. Frequent fires in southern Sudan and deliberate fires for grazing access contribute to habitat loss. Some swamps in Sudan are being drained for construction of a canal to control nearby waterways, causing more habitat loss. [32]
The hamerkop is a medium-sized wading bird. It is the only living species in the genus Scopus and the family Scopidae. The species and family was long thought to sit with the Ciconiiformes but is now placed with the Pelecaniformes, and its closest relatives are thought to be the pelicans and the shoebill. The shape of its head with a long bill and crest at the back is reminiscent of a hammer, which has given this species its name after the Afrikaans word for hammerhead. It is a medium-sized waterbird with brown plumage. It is found in Africa, Madagascar and Arabia, living in a wide variety of wetlands, including estuaries, lakesides, fish ponds, riverbanks, and rocky coasts. The hamerkop is a sedentary bird that often shows local movements.
Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 74 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus Botaurus are referred to as bitterns, and, together with the zigzag heron, or zigzag bittern, in the monotypic genus Zebrilus, form a monophyletic group within the Ardeidae. Egrets do not form a biologically distinct group from herons, and tend to be named differently because they are mainly white or have decorative plumes in breeding plumage. Herons, by evolutionary adaptation, have long beaks.
The grey heron is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia, and also parts of Africa. It is resident in much of its range, but some populations from the more northern parts migrate southwards in autumn. A bird of wetland areas, it can be seen around lakes, rivers, ponds, marshes and on the sea coast. It feeds mostly on aquatic creatures which it catches after standing stationary beside or in the water, or stalking its prey through the shallows.
The purple heron is a wide-ranging heron species. It breeds in Africa, central and southern Europe, and southern and eastern Palearctic. The Western Palearctic populations migrate between breeding and wintering habitats whereas the African and tropical-Asian populations are primarily sedentary, except for occasional dispersive movements. It is similar in appearance to the more common grey heron but is slightly smaller, more slender and has darker plumage. It is also a more evasive bird, favouring densely vegetated habitats near water, particularly reed beds. It hunts for a range of prey including fish, rodents, frogs and insects, either stalking them or standing waiting in ambush.
The great egret (Ardea alba), also known as the common egret, large egret, or great white egret or great white heron, is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and southern Europe. Recently, it has also been spreading to more northern areas of Europe. Distributed across most of the tropical and warmer temperate regions of the world, it builds tree nests in colonies close to water.
The yellow-crowned night heron, is one of two species of night heron in genus Nyctanassa. Unlike the black-crowned night heron, which has a worldwide distribution, the yellow-crowned is restricted to the Americas. It is known as the bihoreau violacé in French and the pedrete corona clara or yaboa común in some Spanish-speaking countries.
The Dalmatian pelican is the largest member of the pelican family and perhaps the world's largest freshwater bird, although rivaled in weight and length by the largest swans. They are elegant soaring birds, with wingspans rivaling those of the great albatrosses, and their flocks fly in graceful synchrony. With a range spanning across much of Central Eurasia, from the eastern Mediterranean in the west to the Taiwan Strait in the east, and from the Persian Gulf in the south to Siberia in the north, it is a short-to-medium-distance migrant between breeding and overwintering areas. No subspecies are known to exist over its wide range, but based on size differences, a Pleistocene paleosubspecies, P. c. palaeocrispus, has been described from fossils recovered at Binagadi raion in Azerbaijan.
The pink-backed pelican is a bird of the pelican family. It is a resident breeder in the swamps and shallow lakes of Africa and southern Arabia; it has also apparently been extirpated from Madagascar.
The spot-billed pelican or gray pelican is a member of the pelican family. It breeds in southern Asia from southern Iran across India east to Indonesia. It is a bird of large inland and coastal waters, especially large lakes. At a distance they are difficult to differentiate from other pelicans in the region although it is smaller but at close range the spots on the upper mandible, the lack of bright colours and the greyer plumage are distinctive. In some areas these birds nest in large colonies close to human habitations.
The painted stork is a large wader in the stork family. It is found in the wetlands of the plains of tropical Asia south of the Himalayas in the Indian Subcontinent and extending into Southeast Asia. Their distinctive pink tertial feathers of the adults give them their name. They forage in flocks in shallow waters along rivers or lakes. They immerse their half open beaks in water and sweep them from side to side and snap up their prey of small fish that are sensed by touch. As they wade along they also stir the water with their feet to flush hiding fish. They nest colonially in trees, often along with other waterbirds. The only sounds they produce are weak moans or bill clattering at the nest. They are not migratory and only make short-distance movements in some parts of their range in response to changes in weather or food availability or for breeding. Like other storks, they are often seen soaring on thermals.
The saddle-billed stork or saddlebill is a large wading bird in the stork family, Ciconiidae. It is a widespread species which is a resident breeder in sub-Saharan Africa from Sudan, Ethiopia and Kenya south to South Africa, and in The Gambia, Senegal, Côte d'Ivoire and Chad in west Africa. It is considered endangered in South Africa.
The African fish eagle or the African sea eagle is a large species of eagle found throughout sub-Saharan Africa wherever large bodies of open water with an abundant food supply occur. It is the national bird of Malawi, Namibia, Zambia, and Zimbabwe. As a result of its large range, it is known in many languages. Examples of names include: Vis Arend in Afrikaans, nkwazi in Chewa, aigle pêcheur in French, hungwe in Shona, inkwazi in isiZulu, and ntšhu in Northern Sotho. This species may resemble the bald eagle in appearance; though related, the two species occur on different continents, with the bald eagle being resident in North America.
The yellow-billed stork is a large African stork species in the family Ciconiidae. It is widespread south of the Sahara and also occurs in Madagascar.
The Goliath heron, 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.
The Bangweulu Wetlands is a wetland ecosystem adjacent to Lake Bangweulu in north-eastern Zambia. The area has been designated as one of the world's most important wetlands by the Ramsar Convention and an "Important Bird Area" by BirdLife International. African Parks began managing Bangweulu in partnership with Zambia's Department of National Parks and Wildlife with the establishment of the Bangweulu Wetland Management Board in 2008.
The nankeen night heron is a heron that belongs to the genus Nycticorax and the family Ardeidae. Due to its distinctive reddish-brown colour, it is also commonly referred to as the rufous night heron. It is primarily nocturnal and is observed in a broad range of habitats, including forests, meadows, shores, reefs, marshes, grasslands, and swamps. The species is 55 to 65 cm in length, with rich cinnamon upperparts and white underparts. The nankeen night heron has a stable population size, and is classified as a species of least concern by the International Union for Conservation of Nature (IUCN).
The African openbill is a species of stork from the family Ciconiidae. It is widely distributed in Sub-Saharan Africa and western regions of Madagascar. This species is considered common to locally abundant across its range, although it has a patchy distribution. Some experts consider there to be two sub-species, A. l. lamelligerus distributed on the continent and A. l. madagascariensis living on the island of Madagascar. Scientists distinguish between the two sub-species due to the more pronounced longitudinal ridges on the bills of adult A. l. madagascariensis. The Asian openbill found in Asia is the African openbill’s closest relative. The two species share the same notably large bill of a peculiar shape that gives them their name.
The maguari stork is a large species of stork that inhabits seasonal wetlands over much of South America, and is very similar in appearance to the white stork; albeit slightly larger. It is the only species of its genus to occur in the New World and is one of the only three New World stork species, together with the wood stork and the jabiru.
The eastern cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Formerly, most taxonomic authorities lumped this species and the western cattle egret together, but the two cattle egrets are now treated as separate species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. It is native to southern and eastern Asia, and Australasia.
The western cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Formerly, most taxonomic authorities lumped this species and the eastern cattle egret together, but the two cattle egrets are now treated as separate species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.
Pero por mucho que la forma del pico del ave esté inspirada en el picozapato (Shoebill en inglés, balaeniceps rex en latín), un ave de color gris del África tropical y oriental, lo que más destaca en la imagen de Loftwing no es su pico sino sus alas.[formatting original]
Loftwings are modeled after birds called shoebills [...] — Hiraoka, designer