Rufous hornbill

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Rufous hornbill
Roufus Hornbill (cropped).jpg
A female Northern Rufous Hornbill ssp. hydrocorax
Southern Rufous Hornbill.jpg
A male Southern Rufous Hornbill ssp. mindanensis
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Bucerotiformes
Family: Bucerotidae
Genus: Buceros
Species:
B. hydrocorax
Binomial name
Buceros hydrocorax
Linnaeus, 1766
Synonyms
  • Buceros mindanensisTweeddale, 1877

The rufous hornbill (Buceros hydrocorax), also known as the Philippine hornbill and locally as kalaw (pronounced KAH-lau), is a large species of hornbill endemic to the Philippines (the largest hornbill in the country). They are referred by locals as the "clock-of-the-mountains" due to its large booming call which typically occur of every hour. It occurs in moist tropical lowland forest. They are now considered to be a threatened species and its reasons for decline being habitat destruction, hunting and poaching for the illegal pet trade.

Contents

It is illegal to hunt, capture or possess rufous hornbills under Philippine Law RA 9147. [3]

Description and taxonomy

A captive ssp. semigaleatus Ee rufous hornbill cebu zoo a.jpg
A captive ssp. semigaleatus

It is endemic to the Philippines, where it occurs in primary, mature secondary and disturbed forests and found across majority of the country except the regions of Mimaropa, Sulu and Western Visayas.

Its described as a large bird with a dark body, rufous legs, chest and neck, an off-white tail and a black fack faced and a yellow thorat. The bill of the nominate subspecies is entirely red, while the bill of the subspecies semigaleatus and mindanensis are pale yellow on the distal half. Birds are sexually dimorphic in which females have striking electric blue eyes and a smaller casque and no eye ring while males have yellow eyes and a larger casque. [4]

Its striking red bill is caused by the oxidation of oils produced by the uropygial gland.

Subspecies

Three subspecies are recognized

The HBW and BirdLife International Illustrated Checklist of the Birds of the World has split this into two species with the Northern Rufous Hornbill consisting of the nominate and the Southern Rufous Hornbill consisting of the semigaelatus and mindanensis subspecies.

Behaviour and ecology

It is sometimes called "the clock of the mountains" because of its periodic noontime call which can be heard up to 1.5 kilometers away. [6] Due to its large size, its wings make a distinct whirring sound in flight. It has been recorded to have been preyed upon by the Philippine eagle. [7]

Seen in flocks of up to 12 birds, the Southern rufous hornbill is occasionally seen with Writhed hornbills forming flocks of up to 20.

Feeding

Rufous Hornbills play a crucial role in maintaining the balance of their ecosystem. They are considered a keystone species due to their omnivorous feeding habits, which allow them to disperse seeds along the forest floor from the fruits they consume and control pest populations of insects they predate on. [8]

Breeding

Recorded to lay eggs from March to May but juveniles have been seen as late as November in Luzon. It nests in cavities of large dipterocarp trees 15 to 30 meters above the ground.

As with other hornbills, females seal themselves within the nest cavity, where they lay the clutch, and remain with the growing young for most or all of the nesting period. In some species, the male helps with the sealing process from outside the nest cavity. The females lays 2 large white eggs, which has weighed 465 to 480 grams. The nestlings and the female are fed by the male through a narrow vertical slit in the sealed nest opening, at times joined by non-breeding helper males. [9] Nesting time will last in average of 4–6 months. In this duration the male will provide food to his confine female and nestling. They are monogamous and maintain the year- pair bonds and will be paired together for many years’ time and engage a courtship feeding.

Habitat and conservation status

A captive female ssp. hydrocorax Buceros hydrocorax - Weltvogelpark Walsrode 2011-07.jpg
A captive female ssp. hydrocorax

This species occurs largely in primary evergreen dipterocarp forests, but also uses secondary forest. The Northern rufous hornbill has recorded up to 760 meters in Luzon while its southern counterpart has been recorded up to 2,100 meters above sea level on Mt. Apo.

Subspecies B. h. mindanensis; illustration by Joseph Smit, 1881 Buceros hydrocorax mindanensis.jpg
Subspecies B. h. mindanensis; illustration by Joseph Smit, 1881

This species has been classified as vulnerable. It is believed that the North Rufous Hornbill is more threatened as the National List of Threatened Terrestrial Fauna of the Philippines has classified it and Endangered while classifying the southern species or sub-species as Vulnerable.

This species suffers from substantial hunting pressure and widespread loss of habitat as a result of logging and conversion to agriculture. Continued subsistence hunting and felling of remnant dipterocarp forests for agriculture are thought to be further depressing population numbers, and the range is now highly fragmented and likely suffering from an acute lack of suitable nesting trees, at least in parts of the range. Hunters climb up nesting trees to capture the mother and its chicks for the illegal wildlife trade. Hunting for sport and food has been recorded throughout its range.

The Northern rufous hornbill occurs in a few protected areas such as Quezon Protected Landscape, Bataan National Park, Northern Sierra Madre Natural Park, Aurora Memorial National Park and Kalbario–Patapat Natural Park. The Southern rufous hornbill occurs in Samar Island Natural Park, Mount Apo, Pasonanca Natural Park. However, despite occurring in numerous protected areas, actual protection from illegal logging, hunting and capture for the wildlife trade is lax. [10]

In 2014 Adams, Ilocos Norte in which the Vice-Mayor's son was photographed carrying a deceased juvenile that he just shot. [11] This species has gone locally extinct in Cavite in Mt. Palay-palay due to hunting and the construction of roads and the Kaybiang Tunnel.

Related Research Articles

<span class="mw-page-title-main">Hornbill</span> Family of birds

Hornbills are birds found in tropical and subtropical Africa, Asia and Melanesia of the family Bucerotidae. They are characterized by a long, down-curved bill which is frequently brightly coloured and sometimes has a horny casque on the upper mandible. Hornbills have a two-lobed kidney. They are the only birds in which the first and second neck vertebrae are fused together; this probably provides a more stable platform for carrying the bill. The family is omnivorous, feeding on fruit and small animals. They are monogamous breeders nesting in natural cavities in trees and sometimes cliffs. A number of mainly insular species of hornbill with small ranges are threatened with extinction, mainly in Southeast Asia.

<span class="mw-page-title-main">Visayan hornbill</span> Species of bird

The Visayan hornbill is a hornbill found in tropical moist lowland forests of the Philippines in the Western Visayas region which includes the islands of Panay, Negros and formerly as well as the island of Masbate, and formerly Ticao, in the Philippines. As is the case with all five Philippine tarictic hornbills, formerly considered to be just one species.It is declining due to habitat destruction, hunting and the illegal wildlife trade.

<span class="mw-page-title-main">Walden's hornbill</span> Species of bird

Walden's hornbill locally called dulungan, also known as the Visayan wrinkled hornbill, rufous-headed hornbill or writhe-billed hornbill, is a critically endangered species of hornbill living in the rainforests on the islands of Negros and Panay in the Philippines. It is closely related to the writhed hornbill, but can be recognized by the yellow throat and ocular skin in the male, and the blue throat and ocular skin in the female. Its binomial name commemorates the Scottish ornithologist Viscount Walden.

<span class="mw-page-title-main">Mindanao hornbill</span> Species of bird

The Mindanao hornbill, also known as the Mindanao tarictic hornbill, is a medium-small species of hornbill found in the canopy of rainforests on Mindanao, Dinagat, Siargao and Basilan in the southern Philippines. All five Philippine tarictics we're once considered a single species. It is declining due to habitat destruction, hunting and the illegal wildlife trade.

<span class="mw-page-title-main">Great hornbill</span> Bird species

The great hornbill, also known as the concave-casqued hornbill, great Indian hornbill or great pied hornbill, is one of the larger members of the hornbill family. It occurs in the Indian subcontinent and Southeast Asia. It is predominantly frugivorous, but also preys on small mammals, reptiles and birds. It has been listed as Vulnerable on the IUCN Red List since 2018. It is known to have lived for nearly 50 years in captivity. Due to its large size and colour, and importance in many tribal cultures and rituals, the Government of Kerala declared it as the official Kerala state bird.

<span class="mw-page-title-main">Philippine eagle-owl</span> Species of owl

The Philippine eagle-owl is a vulnerable species of owl belonging to the family Strigidae. It is endemic to the Philippines, where it is found in lowland forests on the islands of Catanduanes, Samar, Bohol, Mindanao, Luzon, Leyte and possibly Sibuyan. While it is the largest owl in the Philippines, it is relatively small compared to other members of its genus. It is a vulnerable species with its population on the decline. Its main threats are habitat destruction, hunting and poaching for the pet trade.

<span class="mw-page-title-main">Wreathed hornbill</span> Species of bird

The wreathed hornbill is an Old World tropical bird of the hornbill family Bucerotidae, also called bar-pouched wreathed hornbill due to its distinctive blue-black band on its lower throat sac. It is named after its characteristic long, curved bill that develops ridges, or wreaths, on the casque of the upper mandible in adults. Males are black with a rufous crown, a white upper breast and face, and a yellow featherless throat. Females are uniformly black with a blue throat and are slightly smaller than males.

<span class="mw-page-title-main">Bucerotiformes</span> Order of birds

Bucerotiformes is an order of birds that contains the hornbills, ground hornbills, hoopoes and wood hoopoes. These birds were previously classified as members of Coraciiformes. The clade is distributed in Africa, Asia, Europe and Melanesia.

<span class="mw-page-title-main">Palawan hornbill</span> Species of bird

The Palawan hornbill is a large forest bird endemic to the Philippines. It is one of the 11 endemic hornbills in the country. It is only found in Palawan and nearby islands of Balabac, Busuanga, Calauit, Culion and Coron. It is locally known as "talusi" in the language Cuyunon. It is threatened by habitat loss, hunting and trapping for the cage-bird trade.

<span class="mw-page-title-main">Blue-backed parrot</span> Species of bird

The blue-backed parrot, also known as Müller's parrot and Burbridge's parrot is a large, endangered species of parrot endemic to the Philippines. It is found in tropical moist lowland forest but is now feared locally extinct in a large part of its range including Negros, Panay, Leyte, Luzon and Polilio. The only recent records are in Samar, Mindanao and Tawi-tawi. Flocks are small and often active at night. Its main threats are habitat loss and trapping for the pet trade.

<span class="mw-page-title-main">Writhed hornbill</span> Species of bird

The writhed hornbill, also known as the Mindanao wrinkled hornbill, is a species of hornbill in the family Bucerotidae. It is endemic to primarily lowland forests on the Philippine islands of Mindanao, Dinagat and Camiguin Sur. It formerly included the Walden's hornbill as a subspecies, but unlike that species, both sexes of the writhed hornbill have orange-red throat and peri-ocular skin. The writhed hornbill is threatened by habitat loss and hunting.

<span class="mw-page-title-main">Oriental pied hornbill</span> Species of bird

The oriental pied hornbill is an Indo-Malayan pied hornbill, a large canopy-dwelling bird belonging to the family Bucerotidae. Two other common names for this species are Sunda pied hornbill (convexus) and Malaysian pied hornbill.

<span class="mw-page-title-main">Sulu hornbill</span> Species of bird

The Sulu hornbill, or Montano's hornbill, is a species of hornbill in the family Bucerotidae. It is endemic to the Sulu archipelago in the Philippines, with the remaining populations in Tawi-Tawi with it believed to be hunted to extinction on Jolo. Its natural habitat is tropical moist forests. It is threatened by habitat loss as well as potential harvesting for food. Its diet includes fruit, insects, and small lizards.

<span class="mw-page-title-main">Luzon hornbill</span> Species of bird

The Luzon hornbill, sometimes called Luzon tarictic hornbill, is a species of hornbill in the family Bucerotidae. It is endemic to forests on Luzon and nearby islands in the northern Philippines. All five Philippine tarictics were once considered a single species.It is declining due to habitat destruction, hunting and the illegal wildlife trade.

<span class="mw-page-title-main">Mindoro hornbill</span> Species of bird

The Mindoro hornbill is a species of hornbill in the family Bucerotidae. It is endemic to forests on Mindoro in the Philippines found in tropical moist lowland forests. As is the case with all five Philippine tarictic hornbills, formerly considered to be just one species. It is the only tarictic hornbill where both sexes are creamy-white and black. The sexes are very similar, differing primarily in the colour of the ocular ring. It is threatened by habitat loss, and is consequently considered endangered by the IUCN.

<span class="mw-page-title-main">Samar hornbill</span> Species of bird

The Samar hornbill is a species of hornbill in the family Bucerotidae. It is found in forests on the islands of Samar, Calicoan, Leyte and Bohol in the east-central Philippines. As is the case with all Philippine tarictic hornbills, it has been considered a subspecies of Visayan hornbill Alternatively, it is considered a subspecies of Mindanao hornbill.

<span class="mw-page-title-main">Montane racket-tail</span> Species of bird

The montane racket-tail, also known as the Luzon racket-tail, is a species of parrot in the family Psittaculidae. It was previously considered conspecific with the Mindanao racket-tail. This bird is endemic to the mountainous regions of northern Luzon, Philippines. It faces threats from habitat loss and the cage bird trade. Under Philippine Law RA 9147, it is illegal to hunt, capture, or possess rufous hornbills.

<span class="mw-page-title-main">Rufous-lored kingfisher</span> Species of bird

The rufous-lored kingfisher, also known as Winchell's kingfisher, is a species of bird in the kingfisher family Alcedinidae. It is endemic to the Philippines, its natural habitat being lowland forests. It is threatened by deforestation, and the International Union for Conservation of Nature (IUCN) has assessed it as a vulnerable species.

<span class="mw-page-title-main">Southern rufous hornbill</span> Species of hornbill

The Southern rufous hornbill, is a large species of hornbill endemic to the Philippines. It inhabits Mindanao, Dinagat, Siargao, Balut, Bucas, Talikud and Basilan islands of the Philippines. It prefers rainforest habitats and eats fruits, small animals, insects, and seeds. It is threatened by hunting, illegal pet trade, and use of biological resources in their habitat which all leads to their population declining.

References

  1. Buceros hydrocorax, IUCN Red List, 2014
  2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. 11th Congress. "Republic Act No. 9147". Official Gazette of the Philippines.{{cite web}}: CS1 maint: numeric names: authors list (link)
  4. "Rufous Hornbill – eBird". ebird.org. Retrieved 2024-09-03.
  5. Allen, Desmond (2020). Birds of the Philippines. Barcelona: Lynx and Birdlife Guides International. pp. 200–201.
  6. Ortiz, Margaux C. (2 February 2013). "Hornbills in the city: Clock ticking on nature's timekeeper". Philippine Daily Inquirer. Retrieved 9 May 2013.
  7. "Searching for the Philippine Eagle in the Angat Watershed Forest Reserve".
  8. Matutes, Heremerose; Densing, Libertine Agatha (2022-05-21). "Avifauna composition and communities in Leyte Sab-a Basin Peatland and its vicinity in Northeastern Leyte, Philippines". Journal of Wildlife and Biodiversity. 6 (2): 35–60. doi:10.5281/zenodo.6569636.
  9. Witmer, Mark (1993). "Cooperative Breeding by Rufous Hornbills on Mindanao Island, Philippines" (PDF). The Auk. 110 (4): 933–936. doi:10.2307/4088652. JSTOR   4088652.
  10. Kirwan, Guy M.; Kemp, Alan C.; del Hoyo, Josep; Collar, Nigel; Boesman, Peter F. D. (2021). "Rufous Hornbill (Buceros hydrocorax), version 2.0". Birds of the World. doi:10.2173/bow.rufhor1.02species_shared.bow.project_name. ISSN   2771-3105.
  11. "Photo of hunter with dead hornbill sparks online outrage". GMA News. April 7, 2014.
 4. Clarido, Aiza P. (2017). Dark-winged Clock: Hornbill