Buceros
| Buceros | ||||||||||
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Rhinoceros bird, male |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Buceros | ||||||||||
| Linnaeus , 1758 |
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Buceros is a genus of hornbills (Bucerotidae), whose representatives are native to Southeast Asia. A German name is not established. However, they are sometimes referred to as great hornbills or great hornbills .
Like all hornbills, the species belonging to the genus Buceros are cave-breeders. The female spends several weeks in a tree cavity, the entrance to which is walled up except for a narrow crack. The male feeds them through this narrow gap and later also the young birds.
Three species are assigned to the genus. The population situation of the rhinoceros bird and the double hornbill are indicated by the IUCN as being near threatened . The IUCN sees the population of the firehorn bird more critically and indicates that it is endangered ( vulnerable ).
features
Buceros are large to very large hornbills with a body length of 60 to 105 centimeters. The hornbill reaches a body length of more than one meter and is the gehörendem also among the hornbills helmeted hornbill of the largest forest-dwelling birds. There is no significant difference in size between the sexes. However, the featherless skin around the eye differs according to gender and the females lack black markings on the beak. The control springs have a black end band in two types. On the other hand, the tail of the fire hornbill is completely white.
Beak attachment, beak and large parts of the white plumage are colored reddish, yellowish or orange by rump secretions.
distribution
All three Buceros species occur in Southeast Asia.
The range of the double hornbill is the largest of the three species and extends from India through southern China to Sumatra. In India, the range of the double hornbill is disjoint . An isolated population lives in the Western Ghats , a mountain range along the west coast of India, and represents the westernmost distribution area of the genus. The double hornbill is also found in the foothills of the Himalayas from Uttar Pradesh to Assam. The distribution area also extends over the south of Nepal and the north of Bangladesh. They are also found in Myanmar and on some densely forested islands of the Mergui Archipelago in the northern Andaman Sea on the west coast of Myanmar in the Indian Ocean . In China, the double hornbill occurs in the west (in Yingjiang ) and south (in Xishuangbanna ) of Yunnan . They are also represented in Vietnam, Laos, Cambodia and Thailand. The Malay Peninsula is also part of their range, where they are also found on islands near the coast. An isolated population also lives on Sumatra.
The range of the rhinoceros bird partly overlaps with that of the double hornbird. The nominate form ( B. r. Rhinoceros ) is native to the Malay Peninsula and the island of Sumatra . Until 1950 the distribution area extended to Singapore. The subspecies B. r lives on Borneo . borneoensis , on Java B. r. silvestris .
The distribution area of the fire hornbird are the Philippines, which makes it the species within the bureau that is farthest to the east. The nominate form occurs on the islands of Luzon and Marinduque . The Mindanao fire hornbill occurs on Mindanao and Basilan and has also been observed on the islands of Dinagat and Siargao as well as Balut , Bucas Grande and Talicud . The Samar hornbill occurs on Samar , Leyte , Bohol , Panaon and Buad . He has also been seen on calicoan and biliran .
habitat
The habitat of all three species are evergreen rainforests.
The hornbill occurs on Luzon at altitudes of 760 meters, and on Mindanao it has been observed on the slopes of Apo at altitudes of 2100. The double hornbill is particularly common in forests between 600 and 1000 meters above sea level. In the foothills of the Himalayas and in northern Thailand, however, it can still be found at 2000 meters. It is also found in forests where selective logging has taken place. However, it is not as common there as the smaller hornbill species. Where its range overlaps with the rhinoceros bird belonging to the same genus, the double hornbill is more likely to be found in the higher elevations. The double hornbill is quite common in regions of its distribution area in which there are large contiguous forests. Historically, it has also been a rare bird in more fragmented forest areas such as the Western Ghats .
The rhinoceros bird occurs at altitudes of up to 1400 meters, whereby the rhinoceros bird needs primary forest , i.e. forest largely untouched by humans, due to its nesting habits . He also uses forests with selective logging and also looks for fruit-bearing trees that are near the forest edge. In general, however, he avoids open terrain and avoids flying longer distances over open terrain.
The rhinoceros bird is quite common where there are still suitable habitats for it. On the Malay Peninsula there is a pair in primary forests on 0.5 to 2.5 square kilometers. It is primarily increasing deforestation that is causing the population to decline.
General way of life
Most adult double hornbills and rhinoceros hornbills live in pairs and defend a territory. The flocks observed again and again are subadults and non-breeding sexually mature birds. Depending on the food supply, these nomadic people spread over large areas and occasionally split up into sub-groups looking for food a few hundred meters apart. Both species are true to their location and defend a territory, but they tolerate non-breeding troops when they cross their territory. On the other hand, they show a territorial defensive behavior towards neighboring breeding pairs. The behavior shown then primarily includes a reaction to their calls.
Fire hornbills, on the other hand, live in small groups of three to seven individuals. They respond to calls from neighboring squads of firehornbirds, suggesting that the squads are defending a territory. Otherwise, their calls can be heard very regularly in the morning and evening hours. The calls can still be heard from a distance of 1.5 kilometers. During the rest of the day they are comparatively unkind. Occasionally they are socialized with flocks of Mindana hornbills , which belong to the Asiatic throat pouch hornbills ( acres ). Together with them you look for fruit-bearing trees and resting places.
food
Buceros species, like most hornbill species, are omnivorous. They cover most of their nutritional needs with fruits and seeds, with figs playing a special role as with many hornbills. They also come to the ground to look for animal food and fallen fruit. The animal protein they eat consists mostly of insects and arthropods. At least for hornbills and rhinoceros, it has been proven that they spend a comparatively large amount of time hunting for animal protein. The double hornbill has been particularly well studied here: its hunting behavior includes tearing off tree bark and looking for insects there. Double hornbills mainly eat insects such as beetles, wasps, grasshoppers, crickets, cockroaches and caterpillars. Crabs, snails and earthworms are also part of their food spectrum. Smaller vertebrates are also eaten, including lizards, frogs, geckos, snakes, bats, and various squirrels . Smaller bird species and their eggs and nestlings are also eaten by the double hornbill. The birds captured included green-bearded birds , goat milkers , flag drongo , Hindu collar owls and jungle pygmy owls , eggs and nestlings of bulbuls and pigeons .
species
The following three species are included in the genus:
- Hornbill ( Buceros bicornis )
- Rhinoceros bird , Kalao ( Buceros rhinoceros )
- Fire hornbill, red-brown hornbill ( Buceros hydrocorax )
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 .
- Theo Pagel , Bernd Marcordes: Exotic soft-eaters . Eugen Ulmer Verlag, Stuttgart 2011, ISBN 978-3-8001-5192-9 .
Web links
Single receipts
- ↑ a b Buceros rhinoceros in the Red List of Threatened Species of the IUCN 2016.10. Posted by: BirdLife International, 2016. Retrieved December 23, 2016.
- ↑ Buceros bicornis in the endangered Red List species the IUCN 2015 Posted by: BirdLife International, 2013. Accessed October 31, 2016th
- ↑ Buceros hydrocorax in the Red List of Threatened Species of the IUCN 2014. Posted by: BirdLife International, 2014. Accessed December 4 2016th
- ↑ Cocker, Tipling: Birds and People . P. 326.
- ↑ a b c Kemp: The Hornbills - Bucerotiformes . P. 180.
- ↑ a b Kemp: The Hornbills - Bucerotiformes . P. 186.
- ↑ Kemp: The Hornbills - Bucerotiformes . P. 187.
- ↑ a b Kemp: The Hornbills - Bucerotiformes . P. 191.
- ↑ Kemp: The Hornbills - Bucerotiformes . P. 181.