A LIFE OF THE
THE GREAT HORNBILL Written by Jashalini Muralitharan
Presented by Hornbill Conservation Awareness Campaign
BIRD FAMILIES OF THE WORLD
What is Hornbill Hornbills show considerable variation in size. The smallest species is the black dwarf hornbill (Tockus hartlaubi), at 99.1 g (3.50 oz) and 32 cm (1 ft 1 in) in length. The largest and most massive species appears to be the southern ground hornbill which has an average weight of 3.77 kg (8.3 lb), and can weigh up to 6.3 kg (14 lb) and span about 180 cm (5 ft 11 in) across the wings. Other species rival the southern ground species in length, at up to about 130 cm (4 ft 3 in), including the Abyssinian ground hornbill (Bucorvus abyssinicus), the great hornbill (Buceros bicornis) and, probably the The brightest colours on most longest of all (perhaps exceeding 150 cm (4 hornbills, like this pair of ft 11 in)) thanks in part to its extended tail knobbed hornbills, are found feathers, the helmeted hornbill (Rhinoplax on the beaks and bare skin of vigil). Males are always bigger than the the face and throat. females, though the extent to which this is true varies according to species. The extent of sexual dimorphism also varies with body parts. For example, the difference in body mass between males and females is 1–17%, but the variation is 8–30% for bill length and 1–21% in wing length. The most distinctive feature of the hornbills is the heavy bill, supported by powerful neck muscles as well as by the fused vertebrae. The large bill assists in fighting, preening, constructing the nest, and catching prey. A feature unique to the hornbills is the casque, a hollow structure that runs along the upper mandible. In some species it is barely perceptible and appears to serve no function beyond reinforcing the bill. In other species it is quite large, is reinforced with bone, and has openings between the hollow centre, allowing it to serve as a resonator for calls. In the helmeted hornbill the casque is not hollow but is filled with hornbill ivory and is used as a battering ram in dramatic aerial jousts. Aerial casque-butting has also been reported in the great hornbill. The plumage of hornbills is typically black, grey, white, or brown, and is frequently offset by bright colours on the bill, or by patches of bare coloured skin on the face or wattles. Some species exhibit sexual dichromatism, where the coloration of soft parts varies by gender. Hornbills possess binocular vision, although unlike most birds with this type of vision, the bill intrudes on their visual field. This allows them to see their own bill tip and aids in precision handling of food objects with their bill. The eyes are also protected by large eyelashes which act as a sunshade.
Distribution and Habitat
Close-up of head of a Malabar grey hornbill showing eyelashes
As its name suggests, the Sri Lanka grey hornbill is grey and endemic to Sri Lanka.
The Bucerotidae include about 55 living species, though a number of cryptic species may yet be split, as has been suggested for the red-billed hornbill. Their distribution includes Sub-Saharan Africa and the Indian Subcontinent to the Philippines and the Solomon Islands, but no genus is found in both Africa and Asia. Most are arboreal birds, but the large ground hornbills (Bucorvus), as their name implies, are terrestrial birds of open savanna. Of the 24 species found in Africa, 13 are birds of the more open woodlands and savanna, and some occur even in highly arid environments; the remaining species are found in dense forests. This contrasts with Asia, where a single species occurs in open savanna and the remainder are forest species. The Indian subcontinent has 10 species of hornbills, of which 9 are found in India and adjoining countries, while the Sri Lanka grey hornbill is restricted to the island. The most common widespread species in the Indian subcontinent is the Indian grey hornbill. According to the International Union for Conservation of Nature (IUCN), Indonesia has 13 hornbill species: 9 of them exist in Sumatra, and the rest exist in Sumba, Sulawesi, Papua and Kalimantan. Kalimantan has the same hornbill species as Sumatra, except that the great hornbill is not found there. In the Neogene (at least in the late Miocene), hornbills inhabited North Africa and South Europe. Their remains have been found in Morocco] and Bulgaria.
Behaviour and Ecology Hornbills are diurnal, generally travelling in pairs or small family groups. Larger flocks sometimes form outside the breeding season. The largest assemblies of hornbills form at some roosting sites, where as many as 2400 individual birds may be found.
Hornbills are omnivorous birds, eating fruit, insects and small animals. They cannot swallow food caught at the tip of the beak as their tongues are too short to manipulate it, so they toss it back to the throat with a jerk of the head. While both open country and forest species are omnivorous, species that specialise in feeding on fruit are generally found in forests, while the more carnivorous species are found in open country. Forest-dwelling species of hornbills are considered to be important seed dispersers.
Female great hornbill feeding on figs. Fruit forms a large part of the diet of forest hornbills.
Some hornbills defend a fixed territory. Territoriality is related to diet; fruit sources are often patchily distributed and require long-distance travel to find. Thus, species that specialise in fruit are less territorial.
Hornbills generally form monogamous pairs, although some species engage in cooperative breeding. The female lays up to six white eggs in existing holes or crevices, either in trees or rocks. The cavities are usually natural, but some species may nest in the abandoned nests of woodpeckers and barbets. Nesting sites may be used in consecutive breeding seasons by the same pair. Before incubation, the females of all Bucerotinae—sometimes assisted by the male—begin to close the entrance to the nest cavity with a wall made of mud, droppings and fruit pulp. When the female is ready to lay her eggs, the entrance is just large enough for her to enter the nest, and after she has done so, the remaining opening is also all but sealed shut. There is only one narrow aperture, big enough for the male to transfer food to the mother and eventually the chicks. The function of this behaviour is apparently related to protecting the nesting site from rival hornbills. The sealing can be done in just a few hours; at most it takes a few days. Having sealed the nest it takes a further five days for the first egg to be laid. Clutch size varies from one or two eggs in the larger species to up to eight eggs for the smaller species.
During the incubation period the female undergoes a complete and simultaneous moult. It has been suggested that the darkness of the cavity triggers a hormone involved in moulting. Non-breeding females and males go through a sequential moult. When the chicks and the female are too big to fit in the nest, the mother breaks out the nest and both parents feed the chicks. In some species the mother rebuilds the wall, whereas in others the chicks rebuild the wall unaided. The ground hornbills do not adopt this behaviour, but are conventional cavity-nesters.
Male hornbill transfers a fig to the female
A number of hornbills have associations with other animal species. For example, some species of hornbills in Africa have a mutualistic relationship with dwarf mongooses, foraging together and warning each other of nearby birds of prey and other predators. Other relationships are commensal, for example following monkeys or other animals and eating the insects flushed up by them.
Male black-casqued hornbill (Ceratogymna atrata) on display at the Museum of Osteology.
Taxonomy The family Bucerotidae was introduced (as Buceronia) by the French polymath Constantine Samuel Rafinesque in 1815. There are two subfamilies: the Bucorvinae contain the two ground hornbills in a single genus, and the Bucerotinae contain all other taxa. Traditionally they are included in the order Coraciiformes (which includes also kingfishers, rollers, hoopoes and bee-eaters). In the Sibley-Ahlquist taxonomy, however, hornbills are separated from the Coraciiformes into an order of their own, Bucerotiformes, with the subfamilies elevated to family level. Given that they are almost as distant from the rollers, kingfishers and allies as are the trogons, the arrangement chosen is more a matter of personal taste than any well-established taxonomic practice. All that can be said with reasonable certainty is that placing the hornbills outside the Coraciiformes and the trogons inside would be incorrect. Recent genetic data suggests that ground hornbills and Bycanistes form a clade outside the rest of the hornbill lineage. They are thought to represent an early African lineage, while the rest of Bucerotiformes evolved in Asia. However, another study claims that the ground hornbills diverged first, followed by Tockus. Within Tockus, two clades have been identified based on genetics and vocal types - 'whistlers' and 'cluckers'. The 'cluckers' have been suggested to form a distinct genus, Lophoceros. Bycanistes belongs to a clade of mostly African species that also includes Ceratogymna and Tropicranus. Another member of this clade is the Black dwarf hornbill. The Black dwarf hornbill is typically classified in the genus Tockus but in this study, is a sister species to the White-crested hornbill. If these two species are classified in congeneric, Tropicranus becomes a junior synonym of Horizocerus, as that was one of the old names used for the Black dwarf hornbill. This clade also includes one Southeast Asian species, the White-crowned hornbill.
The red-billed hornbill now
As for the other Asian hornbill species, usually includes several Buceros and Rhinoplax are each other's species-level taxa closest relatives, Anorrhinus is part of a clade that has Ocyceros and Anthracoceros as sister taxa, and Aceros, Rhyticeros, and Penelopides form another clade. However, according to this study, Aceros is polyphyletic; the Rufous-headed hornbill, Writhed hornbill, and Wrinkled hornbill form a clade with the Sulawesi hornbill, and are in turn more closely related to Penelopides. These four species have been classified in a separate genus, Rhabdotorrhinus. Similarly, the Knobbed hornbill is more closely related to Rhyticeros, leaving the Rufous-necked hornbill the only member of the genus Aceros.
Species list in Taxonomic Order This is a list of extant hornbill species, presented in taxonomic order. Image
Genus
Living Species •
Tockus Lesson, 1830 • • • • • • • • Lophoceros Hemprich & Ehrenberg, 1833
• • • •
Red-billed hornbill group o Western red-billed hornbill (Tockus kempi) o Northern red-billed hornbill (Tockus erythrorhynchus) o Tanzanian red-billed hornbill (Tockus ruahae) o Southern red-billed hornbill (Tockus rufirostris) o Damara red-billed hornbill (Tockus damarensis) Monteiro's hornbill (Tockus monteiri) Von der Decken's hornbill (Tockus deckeni) Jackson's hornbill (Tockus jacksoni) Southern yellow-billed hornbill (Tockus leucomelas) Eastern yellow-billed hornbill (Tockus flavirostris) Bradfield's hornbill (Lophoceros bradfieldi) Crowned hornbill (Lophoceros alboterminatus) Red-billed dwarf hornbill (Lophoceros camurus) Hemprich's hornbill (Lophoceros hemprichii) African pied hornbill (Lophoceros fasciatus) African grey hornbill (Lophoceros nasutus) Pale-billed hornbill (Lophoceros pallidirostris)
Image
Genus
Living Species
• Horizocerus Oberholser, 1899
Berenicornis Bonaparte, 1850
•
•
White-crowned hornbill (Berenicornis comatus)
• •
Piping hornbill (Bycanistes fistulator) Trumpeter hornbill (Bycanistes bucinator) White-thighed hornbill (Bycanistes albo�bialis) Brown-cheeked hornbill (Bycanistes cylindricus) Black-and-white-casqued hornbill (Bycanistes subcylindricus) Silvery-cheeked hornbill (Bycanistes brevis)
• Bycanistes Cabanis & Heine, 1860
• • •
• Ceratogymna Bonaparte, 1854
White-crested hornbill (Horizocerus albocristatus) Black dwarf hornbill (Horizocerus hartlaubi)
•
Black-casqued wa�led hornbill (Ceratogymna atrata) Yellow-casqued wa�led hornbill (Ceratogymna elata)
Image Image
Genus Genus
Living Species Living Species
• •
Rhinoceros hornbill (Buceros rhinoceros) Great hornbill (Buceros bicornis) Rufous hornbill (Buceros hydrocorax)
•
Helmeted hornbill (Rhinoplax vigil)
•
Tickell's brown hornbill (Anorrhinus �ckelli) Austen's brown hornbill (Anorrhinus austeni) Bushy-crested hornbill (Anorrhinus galeritus)
• Buceros Linnaeus, 1758
Rhinoplax Gloger, 1841
Anorrhinus L. Reichenbach, 1849
• •
• Ocyceros Hume, 1873
• •
Sri Lanka grey hornbill (Ocyceros gingalensis) Malabar grey hornbill (Ocyceros griseus) Indian grey hornbill (Ocyceros biostris)
Image
Genus
Living Species
• • Anthracoceros L. Reichenbach, 1849
• • •
Aceros Hodgson, 1829
•
Rufous-necked hornbill (Aceros nipalensis)
•
Rufous-headed hornbill (Rhabdotorrhinus waldeni) Writhed hornbill (Rhabdotorrhinus leucocephalus) Sulawesi hornbill (Rhabdotorrhinus exarhatus) Wrinkled hornbill (Rhabdotorrhinus corrugatus)
• Rhabdotorrhinus AB Meyer & Wiglesworth, 1895
• •
• • Penelopides L. Reichenbach, 1849
Palawan hornbill (Antracoceros marchei) Oriental pied hornbill (Anthracoceros albirostris) Malabar pied hornbill (Anthracoceros coronatus) Sulu hornbill (Anthracoceros montani) Black hornbill (Anthracoceros malayanus)
• • •
Luzon hornbill (Penelopides manillae) Mindoro hornbill (Penelopides mindorensis) Mindanao hornbill (Penelopides affinis) Samar hornbill (Penelopides samarensis) Visayan hornbill (Penelopides panini)
Image
Genus
Living Species • •
Rhy�ceros L. Reichenbach, 1849
• • • •
The Indian grey hornbill is an overall grey bird and native to the Indian subcontinent. So are other members of genus Ocyceros.
Papuan hornbill (Rhy�ceros plicatus) Narcondam hornbill (Rhy�ceros narcondami) Plain-pouched hornbill (Rhy�ceros subruficollis) Wreathed hornbill (Rhy�ceros undulatus) Sumba hornbill (Rhy�ceros evere�) Knobbed hornbill (Rhy�ceros cassidix)
All members of Anthracoceros, like these Palawan hornbills, have a pied plumage
Fossil record Bucorvus brailloni – Late Miocene (Morocco) Euroceros bulgaricus – Late Miocene (Bulgaria) Some scientist believe the hornbill evolutionary tree spread from the Indian microcontinent after Gondwana, before India merged with Asia.
The uniquely long-tailed helmeted hornbill is commonly placed in its own genus, though some place it in Buceros
Like all Bycanistes, the black-and-white-casqued hornbill has pied plumage and a dull beak. It is found in wooded habitats in Africa.
Knobbed hornbill, Aceros cassidix, early 19th century, Indonesia
Southern ground hornbill (bluish throat indicates female) about to swallow a grasshopper
Cultural Significance Most species' casques are very light, containing much airspace. However, the helmeted hornbill has a solid casque made of a material called hornbill ivory, which is greatly valued as a carving material in China and [Japan]. It was used as a medium for the art of netsuke. Also used for hunting purposes in places like India.
Status and Conservation None of the African species of hornbills are seriously threatened, but many Asian hornbills are threatened by hunting and habitat loss, as they tend to require primary forest. Among these threatened species, only the plain-pouched hornbill and rufous-necked hornbill are found on the Asian mainland; all others are insular in their distribution. In the Philippines alone, one species (the Palawan hornbill) is vulnerable, and two species (the Mindoro and Visayan hornbills) are endangered. Two of the three critically endangered hornbills, the rufous-headed hornbill and the Sulu hornbill, are also restricted to the Philippines. The latter species is one of the world's rarest birds, with only 20 breeding pairs or 40 mature individuals, and faces imminent extinction. The Ticao hornbill, a subspecies of the Visayan hornbill, is probably already extinct. The other critically endangered species, the helmeted hornbill, is threatened by uncontrolled hunting and the trade in hornbill ivory.
The rufous-headed hornbill is among the most threatened hornbills.
In Popular Culture A hornbill named Zazu is the king's adviser and one of the characters in The Lion King franchise, voiced by Rowan Atkinson in the animated version and John Oliver in the live action version. Hornbill was used as the official mascot of one of Malaysia's political parties, the Democratic Action Party. The Rhinoceros hornbill is the official state animal of Sarawak, a Malaysian state located in Borneo. The great hornbill, a member of the hornbill family, is the official state bird of Kerala, an Indian state. The hornbill is very endangered.
Early nineteenth century drawing of the Rhinoceros hornbill (Buceros rhinoceros), Indonesia.
What is the issue? The critically endangered Helmeted Hornbill Rhinoplax vigil is one of the most unusual hornbills, the only one with a solid casque. However, this is precisely the cause of its downfall. The Helmeted Hornbills have been hunted for their casques in Borneo and traded with China for over a thousand years but in the last nine years, the species has come under new and unprecedented pressure from an exploding demand for casques which are in great demand as a material for carved jewelry and ornaments. The bird is found in virgin lowland forest habitats in Brunei, Indonesia (Sumatra and Kalimantan), Malaysia, south Myanmar and south Thailand; it used to occur in Singapore but is now extinct there. It is a low-density species, even in prime habitat, where it plays an important ecological role in seed dispersal and tends to be absent in disturbed forests, peat swamps, and coastal forests. It has the most specialised diet of any hornbill and particular nest requirements.
Why the urgency? A Helmeted Hornbill casque can fetch around US$1,000 in the black market in China. Extensive poaching is reported in Indonesia (Kalimantan and Sumatra) by organized crime networks which tend to be resourced directly by Chinese nationals or by middlemen. A minimum of 2,878 casques were seized globally in at least 59 seizure incidents between 2010 and 2017; the surge in poaching first discovered by Mr Yok-yok Hadiprakarsa of the Indonesian Hornbill Conservation Society (Rangkong Indonesia). The majority of casques enter China from Shenzhen (Guangdong) and Hong Kong from where they are sent to traditional carving centres in China. The poaching is causing a rapid decline in populations and is feared to spread to Malaysia, Myanmar and Thailand as populations are decimated in Indonesia. In response, BirdLife International elevated the conservation status of Helmeted Hornbill from Near Threatened to Critically Endangered in the IUCN Red List of Threatened Species™ in 2015. This decline also prompted the formalization of the Helmeted Hornbill Working Group, a subgroup of IUCN SSC Hornbill Specialist Group, in May 2017 and a regional species conservation strategy and action plan produced in August 2018. Habitat loss and degradation are also of concern because logging operations particularly target large and live dipterocarp trees which decimate suitable nesting and feeding trees for the species.
The Helmeted Hornbill casques seized in Indonesia
The Opportunity to make a Difference Work by BirdLife Partnership The threats are daunting, being driven by such high profits, that it has been essential to move the species conservation up the political agenda, nationally and globally, and identify the needs for action. BirdLife has played a key role in this work. Red Listing In November 2015, BirdLife uplisted the Helmeted Hornbill’s conservation status in the IUCN Red List of Threatened Species™ from Near Threatened to Critically Endangered. Conservation Alert Dr Nigel Collar of BirdLife International produced a series of articles in 2015 & 2016 highlighting the crisis in BirdingASIA (see Collar 2015a), World Birdwatch (Collar 2015b) and article on BirdLife’s website.
Global Policy & advocacy In September 2016, BirdLife along with partners, sponsored the motion on the Conservation of the Helmeted Hornbill which was adopted at the IUCN World Conservation Congress in Hawaii. The resolution called for strengthening international action and support, encouraging relevant governments to support in situ conservation, strengthen enforcement action and engagement with communities, and raise awareness to reduce demand. Multi-country conservation action planning In May 2017, BirdLife along with Sarawak Forestry Corporation, Wildlife Reserves Singapore and IUCN ASAP, co-organised the Helmeted Hornbill conservation planning workshop at Kubah National Park in Sarawak, Malaysia. The recommendations from the workshop formed the basis for developing the range-wide Helmeted Hornbill conservation strategy and action plan (2018 – 2027) which was recently adopted by a wide range of organisations. The BirdLife International Secretariat provides coordination, strategic guidance and fundraising, while also working on international policy, while BirdLife Partners are active in the field and at national policy levels.
Participants at the Helmeted Hornbill conservation planning workshop in May 2017 in Kubah National Park, Sarawak, Malaysia.
Coordinating the Helmeted Hornbill Working Group: Since July 2017, BirdLife Asia secretariat (through Dr Anuj Jain) and along with Wildlife Reserves Singapore has been coordinating the Helmeted Hornbill Working Group, a subgroup of the IUCN SSC Hornbill Specialist Group, to ensure all conservation efforts are coordinated to maximize efficiency and synergy with various stakeholders across the species range states. Mr Yeap Chin Aik from Malaysian Nature Society (BirdLife partner in Malaysia) is also the Lead for the Habitat theme of the Working Group. 10-year Conservation Strategy and Action Plan: The 10-year, Range-wide Helmeted Hornbill Conservation Strategy and Action Plan (2018 – 2027), outlines a bold, long-term vision: “to ensure that the Helmeted Hornbill thrives in ecologically functional populations across its natural range, valued by local and global stakeholder communities and effectively protected from threats related to poaching, trafficking and habitat loss. “
Helmeted Hornbill: conservation strategy and action plan (2018 – 2027) The plan was officially launched on 29 August in Bangkok, Thailand.
10-Year Action Plan: What needs to be Done? Eliminate Demand argeted behaviour change campaigns are needed to eliminate demand for Helmeted Hornbill products across all consumer communities/countries. Effective Enforcement Effective enforcement of national and international policies and legislation are required ensuring that the CITES Appendix I listing for the species is effectively implemented, banning all commercial trade (including domestic trade). Protected, Restored and Sustainably Managed Key population strongholds need to be identified and appropriately protected, restored and sustainably managed through effective anti-poaching efforts and on-ground protection. Monitored Populations are actively monitored to detect thresholds of concern that should trigger remedial action. Local Communities are Encouraged and Empowered Local communities are encouraged and empowered to protect and conserve their resident Helmeted Hornbill populations. BirdLife is perfectly positioned to play a key role in action plan implementation and save this species, working with Governments and other organisations.
On-The-Ground Efforts Since 2017, several new BirdLife projects on Helmeted Hornbills have been initiated, and existing ones enhanced, involving national Partners and the BirdLife Secretariat. Identifying key population strongholds of Helmeted Hornbill: BirdLife is leading a large collaborative project across the Helmeted Hornbill’s five range countries to map out and secure the species’ key population strongholds. multi-country mapping workshop Burung Indonesia (BirdLife Partner) carrying out Helmeted Horbbill field assessments
To initiate an exchange of data and ideas across the species’ range countries, BirdLife organized a multi-country mapping workshop on 30 May – 1 June 2018 in Kuala Lumpur (Malaysia) where researchers identified known priority areas as well as potentially important strongholds where rapid field assessments need to be conducted. This work was enabled by species distribution modelling conducted by BirdLife. A series of national workshops have been conducted to expand this work with local stakeholders in local languages.
multi-country lessons sharing working group A multi-country lessons sharing working group was organized in March 2020 in Kuala Lumpur (Malaysia) to review progress on field assessments, exchange protocols and share lessons learned. Securing key hornbill sites and engaging local communities Securing key hornbill sites and engaging local communities: BirdLife is working directly through its national Partners at key hornbill sites in Peninsular Malaysia, Sarawak, Sumatra (Indonesia), Thailand and Myanmar to ensure systematic monitoring and protection of hornbill populations.
Indonesia Burung Indonesia (BirdLife Partner) actively manages a key site for Helmeted Hornbills in Sumatra. Several occupancy and population surveys have been conducted at the site in collaboration with international researchers, which has enabled BirdLife and Burung Indonesia to develop a systematic species monitoring plan at the site. Malaysia At the Belum-Temengor site, local communities are engaged in monitoring hornbill nests via a sustained program run for the past 14 years by the Malaysian Nature Society (BirdLife Partner), under the guidance of Mr. Yeap Chin Aik. This work is also supported by BirdLife’s Asia-Pacific Forest Governance project. Myanmar Biodiversity And Nature Conservation Association (BirdLife in Myanmar) has been working in southern Myanmar for more than a decade conducting surveys and population monitoring of globally threatened species such as the Helmeted Hornbill and Gurney’s Pitta. Funding newly secured by BirdLife is helping strengthen the current program. Thailand In July 2018, the Bird Conservation Society of Thailand (BirdLife Partner) and BirdLife organised a workshop with park rangers from Khao Sok and Khlong Saeng forest complex to identify Helmeted Hornbill strongholds and discuss inclusion of Helmeted Hornbills in monitoring patrols by forest rangers in south Thailand. A plan for conducting systematic surveys with the forest department is now being developed.
Key Features • Very long bills are topped with a rectangular casque that extends over the head like a hat • Prefers figs to all other foods, using its huge bill to husk a variety of fruits • During the breeding season, the female may seal herself behind a wall she has built at the entrance of the nest Where in the World? Found in India, southwestern China, Bangladesh, western Thailand, mainland Southeast Asia, including Laos and > Cambodia, the Malaysia Peninsula and Sumatra Lifecycle Despite its strong preference for figs, the omnivorous great Indian hornbill is an accomplished hunter, using its enormous bill to batter prey. Habitat Found mostly in India, as its name implies, the great Indian hornbill lives primarily in evergreen and moist deciduous forests, mainly on the lowland plains; it also can be found along the Himalayan foothills and in northern Thailand, extending up to elevations of 6,500′. The hornbill is rare in the Yunnan province in China, but fairly common throughout South Vietnam. An isolated population of great Indian hornbills inhabits West Ghats along the peninsula, from Kolaba to Tenmalai, and the area along the base of the Himalayas from Utta Pradesh to Assam. The great Indian hornbill regularly uses communal roosts in the forests, perching in the topmost branches, with 3-4 birds per tree. Conservation The great Indian hornbill, also known as the great pied hornbill, is on Appendix II of CITES and listed as vulnerable because of decreasing populations. The decline can be attributed to clearing of forests, which eliminates the birds’ nesting sites and foraging grounds. In addition, hornbills have been hunted for many years in India and Indonesia for both food and as an ingredient in local medicines and rituals. Unfortunately, nesting coincides with the honey-gathering season, and the hornbill’s nesting cavities are discovered along with the bees’ honey in the large trees. Kadar tribesmen believe the hornbill chick’s blood comforts the soul of the deceased. The largest known Indian hornbill casque measured 7.5″ long, 4.1″ wide and 2.1″ high.
The Great Hornbill After bathing, the great Indian hornbill perches and extends its wings for hours, until it dries off and regains its body heat. Features of the Hornbill
Breeding During the breeding season, monogamous hornbills form pairs and return to breeding territories, braying loudly near fruiting trees. Males fight in the air; casque to casque, in order to protect their territories. Courtship rituals, which occur in special breeding areas called leks, include branch-banging and hanging upside down. In addition, the male feeds the female fruit for up to five months before mating, and also will regurgitate fruit into the empty nest, which is usually built in the hollow of a tree. The pair seals off the entrance with droppings, chewed pieces of wood and debris; the female works from inside, the male from outside. The female incubates the 1-3 white eggs for 38-40 days, after which time the female and chicks break down the sealed nest by pecking repeatedly in order to receive food from the male. The parents feed the hatchlings for up to five months by regurgitation; the parent’s gullet may be distended with up to 50 grape-sized fruits. Juveniles join parents in flight upon emerging from the nest. King and Queen
The male’s “crown” (left) differs from the female’s.
Food & Feeding Though the hornbill has a strong preference for figs, the bird also hunts insects, lizards, snakes and nestlings. When it comes to eating, the hornbill is adaptable, employing various feeding methods including picking food up, digging into rotting wood, swooping down from a perch or plucking an item from foliage while in flight. Groups of up to 20 hornbills often make treks after fruit.The bird covers large areas daily by air, targeting fruit trees often within bamboo forests. The great Indian hornbill batters larger prey against tree branches to kill the victim, and softens it up using its bill to crush the dead animal if it is too large to swallow.
Behavior The great Indian hornbill is a social bird. It travels in pairs, small family groups or flocks of up to 40 during monsoon season. This noisy bird’s calls range from low guttural sounds to a loud, reverberating kok that may be repeated at regular intervals. Nestlings make feeble croaking sounds, alternating with whistling noises, while older chicks utter harsh churrs, gradually working up to guttural squeals when handled.The bird also growls loudly when defending the nest from intruders in the trees. The great Indian hornbill flies with 3-4 quick deep flaps, followed by a long glide through the airThis tree-dwelling bird travels between branches by hopping sideways; the hornbill rests in what appears to be a “kneeling� position.
Drying off A hornbill sunbathes after bathing in wet foliage.
Creature Comparisons The great Philippine hornbill (Buceros hydrocorax) weighs 3.5 lbs. and measures 25.5″ in length, considerably smaller than the great Indian hornbill.The adult Philippine hornbill has a casque and similar coloring to its larger relative, and it ranges in the Philippines on the islands of Luzon and Arinduque. Like its Indian cousin, this hornbill feeds on fruit and prefers figs, but it also forages for seeds. Both birds rarely descend from their treetop habitats, and both seal their nesting entrances.
Types of Hornbill
Philippine hornbill
Great Indian hornbill
A Mixed Bag Food Show An abundant supply of figs sates the hearty appetites of a flock of hornbills. A douc langur takes in the show from above.
Stay Away A hornbill, through its posture and threatening approach, warns the monkey to stay away from its figs. The langur quickly complies.
Quick Ambush The hornbill eyes a large oriental long-tailed lizard walking along the ground and prepares to pounce on its unlucky prey.
Meal Preparation The bird grabs the lizard and pounds it against a tree, which softens the flesh, making it easier to swallow.
References https://www.birdlife.org/asia/projects/helmeted-hornbill http://what-when-how.com/birds/great-indian-hornbill-birds/ https://en.wikipedia.org/wiki/Hornbill https://www.google.com/search?q=hornbill&rlz=1C1GCEA_enMY922MY922&oq=hornbi ll&aqs=chrome..69i59l3j69i57j69i59j69i60l3.6959j0j7&sourceid=chrome&ie=UTF-8 Collar, N. J. 2015a. Helmeted Hornbills Rhinoplax vigil and the ivory trade: the crisis that came out of nowhere. BirdingASIA 24: 12 – 17 Collar, N. J. 2015b. Catch this falling star. World Birdwatch 37 (4): 11 – 13 Jain A., Lee J. G. H., Chao N., Lees C., Orenstein R., Strange B. C., Chng S. C. L., Marthy W., Yeap C. A., Hadiprakarsa Y. Y. and Rao M. (Eds) 2018. Helmeted Hornbill (Rhinoplax vigil): Status Review, Range-wide Conservation Strategy and Action Plan (2018-2027). IUCN Species Survival Commission Hornbill Specialist Group.
Notes
Notes
Notes