Trumpeter hornbill
| Trumpeter hornbill | ||||||||||||
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Trumpeter hornbill, male |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Bycanistes bucinator | ||||||||||||
| ( Temminck , 1824) |
The trumpeter hornbill ( Bycanistes bucinator ) is a monotypic bird art from the family of hornbills . Its distribution area is southern Africa. Like all hornbills, the hornbill is also a cave breeder. The female spends up to three months walled in a tree cavity and only leaves the nest cavity together with the fledglings that have fledged. During this time, the male first supplies them and later also the young birds with food.
The IUCN specifies that the trumpeter hornbird is not at risk ( least concern ).
features
The trumpeter hornbill reaches a body length of 50 to 55 centimeters. The tail feathers account for an average of 22.6 centimeters in males and 26 centimeters in females. The males have a beak between 12.1 and 15.4 centimeters. The beak of the females remains slightly smaller and is 9.4 to 12.5 centimeters in length. The gender dimorphism is only slightly pronounced.
Appearance of the males
In the male, the head, neck, front chest and back are glossy black. The upper tail and under tail coverts are white, the tail is black. The individual control springs have white tips except for the middle control spring pair. The underside of the body is white. The wings are black with white tips on the arm wings and the inner hand wings. The beak and the beak horn are blackish. The beak horn is large and often so long that it protrudes over the tip of the beak. In breeding males, the beak horn is red at the rear end. The featherless skin around the eye is dark purple, red or pink depending on the breeding condition of the male. The eyes are red-brown, the legs and feet are black.
Appearance of females and fledglings
The females resemble the males in their plumage, but they remain smaller. The beak is black with a pale yellow tip and a yellow-brown beak base. The beak horn is smaller and ends on the middle half of the beak. The eyes are brown.
Fledglings have plumage that is similar to that of adult birds. However, the beak attachment has not yet been developed for them. The beak is still the same color as the beaks of the females. Feathers still have brown edges on the face and at the tip of the beak. The featherless skin around the eyes is dark gray.
Possible confusion
The range of the trumpeter hornbird overlaps in parts with that of the silver cheek hornbird . The silver cheek hornbill is significantly larger and has a cream-colored beak attachment. It also lacks white plumage on its wings and its underside is less white than the hornbill.
The screech hornbill, belonging to the same genus as the trumpeter hornbill, is smaller than the trumpeter hornbill and has a two-colored beak and beak horn attachment .
Distribution area and habitat
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The distribution area of the trumpeter hornbird extends over large parts of southern Africa. It extends from the south of Kenya, Tanzania, the southeast of Zaire, the north of Angola, Zambia, Malawi, Mozambique and Zimbabwe to South Africa.
The habitat of the trumpeter hornbird are mountain forests, forests along rivers and evergreen forests on the coast. It is also found in hardwood forests and mangrove forests. Trumpeter hornbills, in particular, which inhabit forests along rivers, also frequently seek out savannah areas. The altitude distribution ranges from the lowlands to altitudes of 2200 meters. Trumpeter hornbills occasionally occur in comparatively large numbers where the habitat conditions are ideal for this species. For example, in a mountain forest in Malawi, three breeding pairs were breeding in an area of 110 hectares. In a forest lining a river in South Africa's Eastern Cape , four pairs brooded in an area of 240 hectares.
Way of life
Trumpeter hornbills usually live in pairs or small family groups made up of three to five individuals. Again and again, however, larger groups of up to 48 individuals are observed, and there are resting places where up to 200 individuals occasionally gather. To get to such communal resting places, individual birds cover a distance of up to 15 kilometers. Such resting places are usually a grove of larger trees that stand by a body of water. Such resting places are less common in the dry savannah. Some of the resting places are frequented for years and the number of individuals gathering at night only decreases during the breeding season. The resting places are left again at sunrise. From there, the birds fly in different directions to look for food.
Couples stay together all year round and keep in contact with each other both when foraging for food and when resting at night.
food
Trumpeter hornbills, like almost all hornbill species, are omnivores. However, they cover most of their nutritional needs with small fruits. As with many hornbills, figs play a special role. They eat, among other things, the fruits and seeds of Diospyros mespiliformis , Afzelia , Pterocarpus , sycamore fig , peanuts , various types of figs , feather aralas and serpentine . Trumpeter hornbills also eat the fruits of introduced plants such as the cedar tree , mangoes, lidschis and papaya. They also occasionally eat nectar-filled flowers. In the regions where their distribution area overlaps with the larger silver-cheeked bird, they look forward to smaller fruits.
Like all hornbills, trumpeter hornbills also eat animal food. These include arthropods such as caterpillars, beetles and spiders, wasp nets, centipedes and lobsters . They also eat nestlings of other bird species and eggs. A number of bird species hate trumpeter hornbills, which can be taken as an indication that they are very often nest robbers.
Reproduction
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Trumpeter hornbills are monogamous birds, but according to current knowledge they only defend the immediate vicinity of their nesting cave as a breeding area and do not occupy any larger territory. Nesting caves filled with trumpeter hornbills are occasionally only 200 meters apart. Support of the breeding pair by helpers has been observed several times in this species.
As with many rhino species, courtship feeding is a pre-mating act. Mutual plumage care is also observed in this species. Males and females visit the brood cavity up to two months before the actual start of breeding. The female often slips into the breeding cave and both sexes show actions that can normally be observed when sealing the breeding cave, without, however, obstructing breeding material.
Trumpeter hornbills have a breeding cycle that lasts at least 94 days. From this time 10 to 15 days are allotted to a time when the female is already sitting in the cave but has not yet laid any eggs. The eggs are incubated for 28 days and the nestling period is at least 50 days. Trumpeter hornbills appear to breed in the entire range between September and January, with a peak in the months of October to December.
The trumpeter hornbill uses natural tree hollows as nesting opportunities. Occasionally, as at the Victoria Falls, the trumpeter hornbills also use rock caves on steep slopes. The nests are often only two to three meters above the ground. The trees whose tree hollows are used include the African baobab , sycamore fig, ana tree and the bald cypress ( Harpephyllum caffrum ). The nesting trees are often a greater distance from the areas that offer the trumpeter hornbills suitable feeding grounds. Males often cover several kilometers on the way from the feeding grounds to the nest cavity.
The breeding cavity is sealed by the female except for a narrow gap. The female mainly builds in saliva pellets, which the male brings in his throat and hands over to her at the breeding cave. The male only occasionally brings the clay to the brood cavity in its beak. The female who walled up the brood cavity while she was sitting in the brood cavity also built up her excrement and food pulp. In a more closely examined breeding cave, the material with which the installation was walled up weighed 1.47 kilograms. The male also brings bits of bark, small pieces of wood, twigs and fronds of ferns, which the female uses to line the den. Females and later the young birds, when they have reached a sufficient size for this, also keep the breeding cave clean by excreting through the narrow, open gap. Active breeding caves can therefore also be identified by the excrement that is on the ground in front of the nesting tree.
The clutch of the trumpeter hornbill consists of two to four eggs. The eggs are laid two to three days apart. The female, who at this point has already spent a few days in the brood cavity, starts incubating with the first egg. The young birds hatch accordingly asynchronously. The male provides the female and later the young birds with food. A total of 148 visits by the male to one nest were counted over a period of 78 hours.
The young birds are already able to fly by the time they leave the nesting hole, but have not yet developed this ability enough to cover longer distances. They stay near the brood cavity for another two to three days. Five to seven days after they have flown out, they begin to accompany the parent birds in their foraging for food.
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 .
Web links
- Bycanistes bucinator inthe IUCN Red List of Threatened Species 2016.10. Posted by: BirdLife International, 2016. Retrieved December 10, 2016.
Single receipts
- ↑ a b c Kemp: The Hornbills - Bucerotiformes . P. 248.
- ↑ Bycanistes bucinator in the Red List of Threatened Species of the IUCN 2016.10. Posted by: BirdLife International, 2016. Retrieved December 6, 2016.
- ↑ a b Kemp: The Hornbills - Bucerotiformes . P. 245.
- ↑ a b c Kemp: The Hornbills - Bucerotiformes . P. 246.
- ↑ a b c d e Kemp: The Hornbills - Bucerotiformes . P. 247.