Southern Yellow Beak Toko
| Southern Yellow Beak Toko | ||||||||||
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Southern yellow-billed toko ( Tockus leucomelas ) |
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| Tockus leucomelas | ||||||||||
| ( Lichtenstein , 1842) |
The Southern Yellow-billed Hornbill ( Tockus leucomelas ) is an African bird art that the hornbills belongs (Bucerotidae). It was originally thought to be a subspecies of the yellow-billed toko ( T. flavirostris ), which is now known as the eastern yellow-billed toko . Because of its appearance, it is jokingly referred to as the "Flying Banana" in Namibia.
The population of the southern yellow-billed coconut was classified in the IUCN Red List of Threatened Species in 2016 as " Least Concern (LC) " = "not endangered".
features
The southern yellow-beaked toko is a medium-sized toko and reaches a body length of up to 40 centimeters. The beak is 8.1 to 9.9 inches long in the males. Females have a significantly shorter beak with a length between 6.7 and 8.4 centimeters. Females are also significantly lighter, weighing an average of 168 grams, while males weigh an average of 211 grams. There is no sexual dimorphism , the males and females look alike.
male
The males have a dark gray crown and neck. A wide white stripe runs from the forehead over the eye to the nape of the neck. The ear covers are dashed gray. The back is black with a wide white stripe in the middle of the back. Of the five pairs of control springs, the middle two pairs are completely black, the following control springs are one-third white, the two outer pairs are white with a black base and a narrow black cross band in the middle of the springs.
The throat and front chest are white with gray feather edges, so that these parts of the body appear dashed. The lower abdomen is white. The outer wings are black with white spots in the middle of the outer flag, the other wings are black except for three of the wings, which are white. The elytra are black with large white spots. The beak is yellow and darkens towards the edge of the beak and to a dark brown at the tip of the beak. A flat ridge runs along the upper beak, which is a slightly darker yellow than the rest of the beak. The featherless orbital ring and the bare throat skin are bright flesh-colored. The eyes are yellow, the legs and feet are black.
Females and young birds
The females resemble the male in their body plumage. However, they are slightly smaller, the narrow horn already ends in the middle of the upper beak.
Fledglings are similar to adult birds, but the beak is smaller and pale yellow with gray spots. The eyes are still gray.
voice
The call is a loud, choppy Wuk-Wuk-Wuk , which is a little deeper than that of the Red-billed Tokos ( Tockus erythrorhynchus ).
Possible confusion
From the closely related Eastern Yellow-Beaked Toko , the Southern Yellow- Beaked Toko differs in the facial skin. This is black in the eastern yellow-billed coconut ( T. Flavirostris ), while it is flesh-colored in the southern yellow-billed coconut .
The Southern Yellow -Beaked Toko also shows similarities with the Red-billed Toko and the Monteiro-Toko . The southern yellow-beaked toko is larger than the red-beaked toko and differs from it by the color of its beak. The Monteiro toko is larger, has more white parts on the tail, and the head and neck are darker. The Monteiro Toko also has a strikingly red beak.
distribution
The southern yellow-billed coconut occurs in southern Africa, north to southern Angola , southern Zambia and central Mozambique . In the south, the species extends to central Namibia and northern and eastern South Africa . He settles here in the North Cape , the western Orange Free State , the Zululand and the Transvaal .
It inhabits forest areas, various types of savannahs and dry bushland. In semi-arid savannas, it is usually found near watercourses. It is a common bird in parts of its range. It is particularly numerous in open thorn savannahs. It moves occasionally in individual regions of its distribution area: In the Transvaal, for example, there are seasonal high-altitude hikes, during which it hikes from the hardwood forests of the lowlands to high altitudes with evergreen forests.
food
The diet consists of insects , scorpions , rodents , fruits and seeds. With fast runs and flat jumps, they chase after small reptiles and grasshoppers or prey on termites swarming in flight .
The southern yellow-billed toko finds most of its food on the ground. However, it does not dig as much in loose soil or collections of leaves as the red-billed coconut does, for example . However, it uses its beak as a lever to turn objects. While foraging for food, it prefers places that are not too dense with high vegetation. Most often he looks for places that are covered with low grass or herbs, because there is a greater chance of finding invertebrates here. The fruits that he eats include the fruits of the oil palm.
Way of life
The southern yellow-billed toko occurs singly and in pairs. It is a monogamous bird that defends a territory against conspecifics. At least he tolerates the proximity of the red-billed coconut and the gray- billed coconut - these occasionally have their breeding caves near the southern yellow-billed coconut without any interspecific aggression occurring.
He is mostly on the ground, but also in trees. He is not shy. The southern yellow-beaked toko can be recognized from afar by its peculiar way of flight: three wing beats followed by a gliding flight.
Reproduction
Breeding season
The breeding time varies with the respective distribution area. In Angola, southern yellow-billed cocos brood in October, in Namibia they breed from October to March, in the South African Transvaal from October to December. There you have already seen brooding yellow-billed coconut from January to March, but these are probably second clutches.
At the beginning of the breeding season, the pair is increasingly examining trees for nesting holes. Unlike many other Toko species, they use clay to seal cracks on the outside. The male carries clay in its beak, which is then built up by the female. She also uses her own droppings to wall up the crevices. Even in this phase it occasionally slips into the brood cavity. The male also begins courtship feeding at this time and increasingly supplies the female with food that he brings.
The incubation cycle lasts 70 to 76 days. 24 days are allotted to the incubation of the eggs and 42 to 47 days to the nestling time of the young birds. The female sits four to five days before the first egg is deposited in the brood cavity, which is walled up except for a narrow gap. During the time in the breeding cave, it moults.
Nesting cavity
Suitable tree hollows can be found in the marula tree and other trees of the genus Sclerocarya , the liver sausage tree , acacias , trees from the genus of long filaments , the genera Peltophorum , Lannea , Albizia , ebony trees , myrobalans and mopanes . The nest cavity has a diameter of about 20 centimeters, the floor of the cavity is about 11 centimeters below the gap opening. The nest cavity is laid out with leaves, grass and bits of bark, which the male carries.
The nestlings lay eggs and grow up
The clutches comprise two to six eggs; in the Transvaal, an average of 3.7 eggs per clutch were found in the nests examined. As is not unusual for cave breeders, the eggs are white-skinned. The laying interval between the individual eggs of the clutch is one to four days. The laying distance usually increases with the size of the clutch. Incubation begins when the first egg is deposited. The nestlings hatch asynchronously according to the laying distance.
The male carries food to the breeding cavity. During the first days of the nestlings, the female passes the food on to the nestlings. By the time they are 10 to 15 days old, however, these are already so large that they can reach the crevice and take away the food from the male. The female leaves the brood cavity when the oldest nestling is around 20 days old. The nestlings remaining in the breeding cave seal the cave again on their own except for the narrow gap. The female, who at this point has completely moulted, then begins to feed the nestlings together with the male.
The young birds are able to fly immediately after leaving the nest cavity and are able to build up in the vicinity of the nest cavity. They will be fed by the parent birds for several days. Due to the asynchronous hatching, not all nestlings leave the den at the same time. The remaining ones seal the brood cavity again except for a narrow gap. Younger nest siblings occasionally leave the cave only 10 days after the oldest nestling fledged. Fledglings that have fledged stay with their parents and defend the territory with them.
Causes of mortality
Adult Southern Gelbschnabeltokos be among others by the Secretary , the Lanner Falcon , tawny eagle , martial eagle and jugglers , the cave consecration , the Wahlberg Eagle and African hawk eagle , the Dark Chanting Goshawk , the Mohr hawk , spotted eagle owl and Verreaux's Eagle-Owl captured. ,
attitude
Southern yellow-billed tokos are occasionally shown in zoological gardens. They have already reached an age of more than 22 years there.
literature
- 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 .
- Gordon Lindsay Maclean: Robert's Birds of South Africa , 6th Edition
Web links
- Tockus leucomelas in the endangered Red List species the IUCN 2012. Posted by: BirdLife International, 2012. Retrieved on 3 October 2016th
- Videos, photos and sound recordings of Tockus leucomelas in the Internet Bird Collection
- Nice photo of a south. Yellow Beak Toko
- www.biologie.uni-hamburg.de - photos
- Calls of the southern yellow-billed coconut on Xeno-Canto
Individual evidence
- ↑ Tockus leucomelas in the endangered Red List species the IUCN 2016 Posted by: BirdLife International, 2016. Retrieved on 3 October 2017th
- ↑ Kemp: The Hornbills - Bucerotiformes . P. 137.
- ↑ Calls of the southern yellow-billed coconut on Xeno-Canto , accessed on October 3, 2016
- ↑ a b c d e Kemp: The Hornbills - Bucerotiformes . P. 138.
- ↑ a b c Kemp: The Hornbills - Bucerotiformes . P. 139.
- ↑ Kemp: The Hornbills - Bucerotiformes . P. 140.
- ↑ Grummt, H. Strehlow (Ed.): Zoo animal keeping birds . P. 548.