The theory of evolution includes the possibility of mutations. Hornbill it confirms. In nature, there are few animals with such an illogical appearance. Moreover, this is not one species, but the whole family. Its scientific name, Bucerotidae, dates back to the Greek word buceri (cow or bovine horn).
Description and Features
Birds of this family live in the African tropics and subtropics, in southeast Asia, on the islands of Melanesia, that is, their range is a third of the world's land. All birds in this family have two common and unique features:
- Disproportionately large curved beak. Often on the head and beak is placed an impressive horn outgrowth remotely resembling a helmet.
There are different versions of the appearance of such a beak and a helmet. But no one is certain.
- The first and second cervical vertebrae are fused.
The integration of the two vertebrae is probably due to the need to compensate for the feathering of the beak. The remaining characteristics of birds in the family correspond to their size and are not exclusive. Weight ranges from 100 grams to 6 kilograms. Length - from 30 centimeters to 1.2 meters.
Wingspan from 40 centimeters to 1.6 meters. The body is stocky, the legs are strong. Toes have grown together in all species except the African horned raven. A strong physique is caused by an overgrown upper and lower jaw, that is, a beak.
Males are more females. The beak of males may be one third superior to the beak of partners. The remaining sizes differ not so strikingly: only 17-20 percent. Coloring also varies.
In most species, the color of plumage varies depending on gender. But there is completely black rhino bird. Males and females of this species differ only in the color of the beak.
All species of these birds live in dense tropical forests. They fly well, but are not adapted to long and high-speed flights. During the flight, loose fly feathers make a considerable noise.
The family of these birds is diverse and numerous. It includes 14 genera, which include 57 species. The classification of rhinoceros birds has often changed due to the complexity of their study, and more recently, in connection with new data obtained from genetic studies. Southeast Asia, including India, southern China, Indonesia, the Malay Archipelago and Melanesia are inhabited by:
- Aceros - Asian Kalao.
Calao is a Spanish rhino. Another name: indian rhino bird. This genus includes 5 species of impressive birds. They live in the Indian subcontinent and in Southeast Asia. Beak, head, part of the neck brightly colored. The rest is dominated by dark colors. The plumage is white.
- Anorrhinus is a short-toed kalao.
3 species are included in this genus. These are medium sized birds. The maximum weight is close to a kilogram. They wear a dark helmet above their heads and beaks. Their range is located on the northern border of the common, for all rhinoceros birds, habitat. It stretched from northeast India to western Thailand and northwest Vietnam.
- Anthracoceros is a rhinoceros bird or black rhino.
This genus includes 7 species. Their feature is that the helmet, in size, is slightly inferior to the beak and is similar to it in shape. The range of this genus stretched from India to the Philippines. The species living in the Malay Islands (Suluan bird) is endemic.
- Berenicornis - white-crested feces or crowned feces, or white-tailed feces, or crested feces.
Monotypic genus. It lives in the Asia-Pacific region. In the subtropical forests of Brunei, Myanmar, Thailand. Not a small bird, its weight reaches 1.5 kilograms.
- Buceros - homrai, or two-horned kalao.
This genus includes three species. They nest mainly in India and Nepal. The most impressive of them bird: big rhino or large Indian kalao.
- Ocyceros - Asian Currents.
The genus combines three species that live on the Indian subcontinent.
- Penelopides is a Filipino hornbill.
6 species of this genus nest in the Philippines and on the island of Sulawesi in Indonesia. Feathered small. They feed on the fruits of tropical trees. A distinctive feature is the ribbed surface of the beak.
- Rhinoplax - hat-billed kalao.
Monotypic genus. It lives on the southern tip of Indochina, on Sumatra and Borneo. Heavy bird. Its weight reaches three kilograms. The weight of the beak helmet is 12% of the total mass. The beak and helmet are used as weapons in fights between males. The local population believes that the world of the living and the dead is separated by a river, which is protected by this particular bird.
- Rhyticeros are folded rhinos.
This genus includes 5 species of medium and large birds. The main feature is the presence of folds on the beak helmet. It nests in the tropical forests of the Indochina Peninsula and on the Solomon and other Pacific islands.
The number of rhino birds is rapidly declining. The Asian branch of this genus is particularly affected. Deforestation and hunting reduce their chances of survival. Asian kalaos, for example, are already rare in India and have completely disappeared in Nepal. Their total number is estimated at only 10 thousand adults.
Asian currents have adapted to coexistence next to man: they can be found in the cities of India, where they settle in the hollows of old trees. In sub-Saharan Africa, five genera of feathered rhinos nest:
- Bucorvus is a horned raven.
It has nothing to do with the raven. Rhinoceros Rhino Bird - So thought before. Now scientists attribute it to a detachment of rhinoceros birds.
This is a difficult creation up to 6 kilograms weighing up to 110 centimeters long, with a wingspan of up to 1, 2 meters. The main feature of these birds: they prefer to walk on the ground. This genus includes two species.
- Bycanistes - African Calao.
The genus has 5 species. Sometimes the whole genus is named after one of the species - silver-winged kalao. These are medium birds with a length of up to 80 centimeters, weighing up to 1.5 kilograms. As many feces eat, for the most part, the fruits of tropical plants.
- Ceratogymna - Helmet-bearing kalao.
In this genus, there are three species of birds that feed on insects and fruits. Inhabit the rainforests of black Africa. There is a species of black-clawed kalao that feeds exclusively on the fruits of the oil palm.
- Tockus - currents (or toko).
The genus includes 14 species. A typical representative of this genus is tropical rhino bird small size. Body length 30-50 centimeters, weight 100-500 grams.
- Tropicranus is a white-crested rhinoceros.
The genus includes three subspecies, characterized by the number of white feathers on the head and neck. Hornbills that have settled in Africa prefer subtropical and tropical forest wilds, and are difficult to count. It is believed that they are not threatened with extinction.
Lifestyle & Habitat
A variety of shapes, colors and sizes ends when it comes to lifestyle. In this, the relatives are very similar. Social organization is simple: they live in small flocks or in pairs. Birds create stable pairs. In most species, these unions persist throughout their lives.
Most species live and nest in dense impenetrable tropical and subtropical forests. But currents and horned crows feed and make nests in woodlands, shrubs, and savannahs. Moreover, rhinoceros crows generally do not like to fly and spend more time on the ground looking for food in walking order.
These birds are omnivores. Small animals and insects are used as animal food. The fruits of tropical trees are the main component of plant foods. Flowers of trees and berries are also involved. Eating a lot of fruits, birds involuntarily spread seeds in the forest. That is, they contribute to the cultivation of trees and shrubs.
Birds that prefer animal food are tied to a specific territory and protect it from brethren. Those species that have chosen a vegetarian diet constantly roam in search of ripe fruits, sometimes over long distances.
Reproduction and longevity
The breeding season for birds begins in the spring, with the end of the rainy season. Males are looking for a place suitable for arranging a nest. These are natural cavities inside old trees, abandoned by the shelters of other birds. Sometimes these are earthen and rocky niches. Suitable space able to accommodate a bird.
The male chooses this or that individual as an object of courtship. And begins to present gifts. These are berries, fruits or small animals. Females refuse offerings. But the male is patient and persistent. He continues to present the chosen one. And in the end, gaining the favor of the female.
At this point, the place for the future nest should be ready. The male shows his partner. Inspection of the nest is accompanied by the delivery of goodies. If you like the treats and the place for the nest, the birds finish building the nest together and mating occurs. The female settles in the nest and itself closes the entrance. The male delivers suitable material for this: moist earth, clay, twigs, dry grass.
It turns out to be an enclosed space with a small inlet, into which only the beak can be inserted. All hornbills except horned crows do this. They do not close the entrance to the dwelling. As a result, females can leave a nest for a while during the nestlings.
Five days after the start of confinement, the female lays eggs. Large feathered rhinos lay one or two eggs. Small species, like currents, can lay up to 8 eggs.
The incubation period lasts from 23 to 45 days, during which the female sheds completely. After the appearance of the chicks, the entrance to the nest is hacked. A pair of birds begins to actively feed offspring, in which the first feathers grow in a few days.
After three to five months, the chicks are ready for the first flight and leave the nest. They take an adult look at one year old. Small rhinos are ready to continue the genus in 2 years, and heavyweights in 4 years. Rhino birds are unique feathered. They require special attention, detailed study and widespread protection.