Hornbill
| Hornbill | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Hornbill |
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Rhyticeros cassidix | ||||||||||
| ( Temminck , 1823) |
The hornbill ( Rhyticeros cassidix ) is a species of the hornbill family that occurs exclusively on Indonesian islands. As is typical for hornbills, the hornbill is a cave breeder. The female walls herself up in the breeding cave except for a narrow gap and occasionally spends more than three months in this breeding cave. They and later the young bird are provided with food by the male.
In 2016, the Red List of Threatened Species of the IUCN classified the population of the hornbill as " Near Threatened (NT) " = "potentially endangered".
Appearance
The hornbill reaches a body length between 70 and 80 centimeters. The male's tail accounts for an average of 26.4 centimeters, while the female's tail is significantly smaller at 19.7 centimeters. The sexual dimorphism is hardly pronounced in this species.
Characteristics of the male
The crown of the head and the back of the head are red-brown, the face and neck are pale red-brown to cream-colored. The body plumage and wings are black, the plumage on top has a metallic green sheen. The tail is white.
The beak is yellow with orange-brown cross grooves and a red-brown, helmet-like beak attachment. The featherless eye ring is pale blue. The bare large throat patch is dark blue with a black band at the bottom. Below the black band, the throat patch is turquoise. The eyes are orange to red, the legs and feet are black.
Features of the female and young birds
The adult females have a body plumage that is largely similar to that of the males. However, they are smaller and have a smaller horn attachment on their beak. The throat and the nape are entirely black. The black band on the featherless throat pouch is less pronounced. The eyes are brown to orange.
In the young birds, both sexes initially show a body plumage that resembles the female. The beak horn is not yet developed. The eyes are dark brown with a yellow ring around the iris.
Distribution area and habitat
The hornbill occurs on the Indonesian island of Sulawesi and on the islands of Lembeh , Togian , Buton and Muna bordering on Sulawesi . The Sulawesi hornbill is only one other species of hornbill in its range. The two species can hardly be confused with one another: the Sulawesi hornbill is significantly smaller. Fledglings and males have red-brown heads and a cream-colored neck, while in the adult females these body parts have black plumage.
The hornbill colonizes tall, evergreen forests in its habitat. While looking for food, it occasionally stays outside of forest areas, for example when it visits individual fig trees or plantations.
The hornbill is common in the lowlands and the mountain forests of the foothills. Its height distribution extends up to 1800 meters, but it is rare at these altitudes. The highest population densities are found where there is an abundant food supply.
Way of life and food
During the breeding season the hornbill lives in pairs. Outside the breeding season, however, there is occasional formation of flocks of up to 50 individuals. These are made up of adult hornbills of both sexes as well as young birds.
The hornbill is predominantly a fruit eater. Figs, like many other hornbills, play a major role in its diet. They make up an average of 69 percent of the food components that are carried to the brood cavity. In individual cases, figs make up 94 percent of the diet. For this reason, it is one of the species of hornbills in which fruits play a particularly important role in the diet. In addition, the hornbill also eats animal daughters; Remnants of various insects were found in his excrement and he probably also steals the nests of the narrow- billed star .
Reproduction
According to current knowledge, hornbills are not territorial. This indicates that in suitable habitats an average of 9.5 active breeding caves are found per square kilometer.
The breeding season begins with the female increasingly starting to inspect tree hollows. Courtship feeding and mutual plumage care of the two partner birds are also among the activities that can be observed regularly at the beginning of the breeding season.
The breeding cave is usually between 13 and 42 meters above the ground. Natural tree hollows in trees with an average diameter of 115 centimeters are used as breeding caves. In the nests examined, the breeding caves were on average 81 centimeters high. The breeding caves are usually used for several years.
The entrance to the brood cavity is narrowed by females except for a narrow gap. She uses her own excrement. The female usually leaves the breeding cave 24 to 32 days before the young bird and then takes care of the young bird together with the male.
Hornbill and human
In some regions of Sulawesi, the skull and horn are worn as an ornament to traditional costumes. Hornbills are also hunted for food and are often kept as pets. Where it is not hunted, it can become trusting and also looks for human settlements in order to eat in the fruit-bearing trees.
The hornbill is also the official bird of the Indonesian province of Sulawesi Selatan .
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 .
Web links
- Rhyticeros cassidix in the Red List of Threatened Species of the IUCN 2012. Posted by: BirdLife International, 2012. Accessed November 1, 2016th
- Calls of the hornbill on Xeno-Canto