Shield beak
| Shield beak | ||||||||||||
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Shield beak |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Rhinoplax | ||||||||||||
| Gloger , 1841 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Rhinoplax vigil | ||||||||||||
| ( Forster , 1781) |
The hornbill ( Rhinoplax vigil ), also called hornbill , is one of the largest members of the hornbill family with a total length of 1.2 meters . The distribution area of this monotypical species is Southeast Asia. Like all hornbill species, the shield beak is also a cave breeder. The call of the shield beak can still be heard two kilometers away and is one of the loudest calls of the animal world in the tropical rainforest of Southeast Asia.
The IUCN classifies the tortoiseshell beak as an endangered bird species because of a very sharp decline in the population.
description
The shield beak reaches a body length between 1.1 and 1.2 meters without the elongated tail feathers. The weight is between 2.6 and 3 kilograms. The male's tail, including the elongated tail feathers, is between 73 and 98.2 centimeters. In the female it is 61.5 to 79 centimeters. A large part of the tail length falls on the middle pair of tail feathers, which protrudes over the other tail feathers by up to 20 centimeters. The beak is comparatively short and measures an average of 19.6 centimeters in the male and 17.1 centimeters in the female.
The neck and throat pouch, head, feet and upper part of the horn attachment are reddish in the male. The neck and head are unobstructed except for a few dark brown feathers on the crown and reddish brown feathers on the cheeks. The lower part of the horn attachment is colored yellow. The red color of the beak and the beak horn can be traced back to the rump secretion with which the shield bird cares for its plumage. Rhinoplax vigil is the only hornbill whose beak is massive, i.e. without air chambers. The horn attachment makes up 10 percent of the bird's total weight. The bird has black dorsal plumage, the tail feathers are brownish, colored black and white at the end. The extended control springs are silver gray and have both the black end band and white spring tips. Like all hornbills, this species also has short, broad and strong wings.
The eyes of the male are dark red to red-brown, the feet and legs are red-brown.
Females resemble males in their body plumage, they are only slightly smaller and the beak has small black speckles at the tip. The featherless skin of the neck and face is pale purple. The throat pouch is turquoise, the eyes are red-brown.
Fledglings resemble the adult female, but the middle pair of tail feathers is not yet the length of the adult. The beak horn is still underdeveloped and the beak is yellowish green. The bare skin of the face and neck is greenish blue, the eyes pale reddish brown.
Possible confusion
In the area of distribution of the shield beak, two other large hornbill species occur with the double hornbill and the rhinoceros bird . Both species have large horn-shaped beak attachments. In both species, the neck and head are feathered except for the bare throat patch. The neck and the back head of the double hornbill are white.
Distribution and way of life
This species occurs in lowland forests and has a large distribution area that extends from southern Tenasserim in Burma to Thailand , the Malay Peninsula , Singapore and the large Sunda islands of Borneo and Sumatra . The habitat are evergreen rainforests up to an altitude of 1100 meters. It also occurs in primary forests with selective logging, but avoids secondary forests. Basically, the habitat requirements are similar to those of the rhinoceros bird, but the shield beak is a much rarer bird than this hornbill species.
Way of life
Shield beaks are tree-dwelling species of hornbills that live mainly in the crowns of tall trees. There are no reports of them occasionally descending to the ground.
Adult shield beaks live in pairs and occupy a territory. Occasionally they are occupied by a young bird and occasionally three to four birds meet at the territorial boundaries. There are also small nomadic troops made up of not yet sexually mature and not breeding adult birds. These usually consist of no more than eight birds and roam a large area in search of food. Calls indicating the territory can be heard at any time between 8 a.m. and 5 p.m. in the afternoon. Usually the calling birds sit in the treetops 30 to 60 meters above the ground. The partner bird, which is also calling, is usually 50 to 100 meters away. Both partner birds defend the territory and respond to the calls of the neighboring couple. They use their massive beaks in territorial fights against conspecifics. Males are reported to occasionally beat their horns against each other for up to two hours. On the other hand, they tolerate the nomadic groups of subadult and non-breeding adult birds in their territory.
food
The shield beak is omnivorous and feeds on fruits, reptiles, smaller birds and their brood. Fruits make up a significant proportion of his diet. According to observations in Malaysia and Kalimantan, figs rich in sugar play a significant role in the diet, as in many other Asian hornbill species. The shield beak spends about half of its foraging for small vertebrates and large arthropods. Mated birds usually hunt alone, but keep in contact with each other by shouting. The massive beak aids the shield beak in removing tree bark to look for arthropods underneath. He may also use his beak when opening tree hollows to prey on foreign bird brood. It was observed, among other things, how first a male and later a female visited the nesting hole of a Sunda oriental hornbill, which is also one of the large hornbills. The male pounded on the back of the nest box while the female inside shouted. However, the male hornbill did not appear at the nest to defend it. A markedly antagonistic behavior was also observed in rhinoceros when a shield beak was near the nesting cavity.
Reproduction
The reproductive biology of this species has not yet been conclusively investigated. According to current knowledge, shield beaks are not tied to any specific reproductive time. Breeding pairs do not raise a young bird every year.
The birds reach sexual maturity at the age of 6 years. As is typical for hornbills, the female, who lays the nest in a tree hollow, walled up in a natural tree hollow to protect against nest robbers. Only a narrow gap remains open for the transfer of food and the expulsion of the excretions. The female only lays 1 to 2 eggs in the nest. So far, only one young bird has been observed in the wild. Presumably, the adult birds can only successfully raise one young bird in the wild. Something similar is described for the closely related rhinoceros bird. The breeding period is approx. 45 days and then the young remain in the nest for up to 80 days. In the wild, it has been observed that young birds were still being fed by the parent birds for six months after they had left the breeding cave.
Danger
The IUCN listed the tortoiseshell beak as ( Near Threatened ) or potentially endangered over a longer period of time because the population was slowly declining, but there was sufficient population size. The reason for the classification was the disturbance of the habitat of the birds. In the past, the species was heavily hunted for its beak and feathers. This species is listed in CITES Appendix I (total trade ban). In addition, several research projects are ongoing to enable better protection of this type. In 2015, the IUCN changed its classification from Near Threatened to Critically Endangered , as habitat destruction in the range of this species has increased significantly and at the same time there is still strong hunting pressure.
Shield beak and human
Similar to the other large hornbills, the tortoiseshell also plays a role in the traditions of the ethnic groups in its area of distribution. The tail feathers, the middle pair of which can reach a considerable length of up to 90 centimeters, adorn the headgear of the young warriors of the Kayan , Kenyah and Kelamtan who have already killed an enemy. The horn is used as earrings for older men.
The horn has been exported to China since the Ming period, where it was made into belt buckles. There is also a long tradition of horn processing in Japan. The horn is still on the market - between 2011 and 2014 alone, more than 1100 skulls and horns were confiscated in Borneo. According to estimates by some experts, more than 6,000 shield beaks are killed annually for the illegal trade, in which the kilogram of horn is more valuable than the ivory of elephants. In India it is sold as a love charm. The trade in the ivory of these birds is sometimes very open: Alan Kemp saw the skull and horns of the shield bird in the 1990s, which were offered for sale in Singapore.
A Malay legend justifies the peculiar calls of the shield beak with the punishment for a malicious murder: A young man hacked through the bamboo scaffolding on which his mother-in-law's hut stood (the repeated hooting of the bird) and was deeply delighted when the mother-in-law died as the hut collapsed (refers to the cackling sounds of the bird, reminiscent of a manic laugh). As punishment for the murder, the young man was turned into a shield beak, who has to go through his misdeeds constantly.
literature
- Mark Cocker, David Tipling: Birds and People. Jonathan Cape, London 2013, ISBN 978-0-2240-8174-0 .
- W. Grummt, H. Strehlow (Ed.): Zoo animal keeping birds. Verlag Harri Deutsch, Frankfurt am Main 2009, ISBN 978-3-8171-1636-2 .
- Alan Kemp: The Hornbills - Bucerotiformes. Oxford University Press, Oxford 1995, ISBN 0-19-857729-X .
- Christopher M. Perrins (Ed.): The FSVO encyclopedia birds of the world. Translated from the English by Einhard Bezzel. BLV, Munich / Vienna / Zurich 2004, ISBN 978-3-405-16682-3 , pp. 386-387 (title of the original English edition: The New Encyclopedia Of Birds. Oxford University Press, Oxford 2003).
- Philip Withfield (ed.): The great world empire of the animals. Planet Medien AG, Zug 1992, ISBN 3-8247-8614-1 , pp. 286, 287 (translation from English)
Web links
- Rhinoplax vigil in the endangered Red List species the IUCN 2015 Posted by: BirdLife International, 2015. Accessed December 4 2016th
- Spektrum .de: A bird more valuable than ivory August 5, 2019
Single receipts
- ↑ a b c d Kemp: The Hornbills - Bucerotiformes. P. 194.
- ↑ Rhinoplax vigil in the endangered Red List species the IUCN 2015 Posted by: BirdLife International, 2015. Accessed December 4 2016th
- ↑ a b Kemp: The Hornbills - Bucerotiformes. P. 193.
- ↑ Kemp: The Hornbills - Bucerotiformes. P. 192.
- ↑ a b c d e Kemp: The Hornbills - Bucerotiformes. P. 195.
- ↑ a b c Kemp: The Hornbills - Bucerotiformes. P. 196.
- ↑ BBC Magazine: The bird that's more valuable than ivory . In: BBC . October 12, 2015. Retrieved December 4, 2016.