Hornbills Bird Teach Us About Sharing

                                                    

 The hornbills are extremely interesting because they have monogamous relationships that last for life. The main reason for this is that their reproduction process requires the female hornbill to trust the male hornbill to feed her for 4 ½ months during the incubation period of her eggs. Before mating, he offers her a food gift (an insect or a fruit). The nest is usually made in a tree hole. She, in fact, muds herself into it! She closes her nest completely with mud and dung and leaves open only enough space for her partner to give her food through this opening during the time she is inside the nest. Can you imagine that Mr Hornbill can bring up to 24,000 fruits for Mrs Hornbill during the whole period of nesting? Wow!

                                             

Great Hornbill

 After 4 months, Mrs. Hornbill tears down the mud around her abode and reappears with her young to present to Mr. Hornbill. Now that’s sharing! There are many other animals that share with each other and depend on that sharing to keep the species alive, but the hornbills may be the ultimate sharers as they are believed to be the birds with the highest occurrence of cooperative breeding. 

What are hornbills?

Hornbills are a group of bird species (about 60 species) from the unique Bucerotidae family. First, all species in the aforementioned family have a specific horn-like growth on their beak (casque). In some species, their casque is made from a hollow, spongy-like material, while in other species their casque is made of a solid ivory-like material. 

      In addition, females have a less pronounced casque compared to their male counterparts. Second, due to the extra weight of the casque, in all hornbills, the first and the second neck vertebrae are fused together. This characteristic is only present in the Bucerotidae (hornbills) family of bird species. Consequently, their neck muscles are much more pronounced and more durable comparing to other bird species.

The great hornbill (Buceros bicornis), also known as the concave-casqued hornbill, great Indian hornbill or great pied hornbill, is one of the larger members of the hornbill family. It is found in the Indian subcontinent and Southeast Asia. Its impressive size and colour have made it important in many tribal cultures and rituals. The great hornbill is long-lived, living for nearly 50 years in captivity. It is predominantly frugivorous, but is an opportunist and will prey on small mammals, reptiles and birds.

Why do hornbills have a casque?

Since nature is very cruel and does not tolerate any harmful attributes (even unnecessary ones, who do not have a harmful or beneficial effect at all), the very appearance of the mentioned changes in the neck indicates a great importance of the casque for the survival of these bird species. On the one hand, it serves as an echo chamber and therefore makes their voice stronger. 

          As an example, in very dense vegetation (rainforests) visually finding a partner becomes extremely difficult (almost impossible). In such areas, the acoustic localization of a potential partner is of primary importance. In other words, during the mating season, the casque allows them to find potential partners that can be extremely remote and visually undetectable. On the other hand, it also serves as a fitting tool between males and its weight is handicapping males in the struggle for daily survival. 

                                            

Southern Ground Hornbill with Long Eyelashes 

      Due to their flying properties, most birds can easily escape from predators and other difficulties in nature, which opens the possibility of survival of males with poor genetic quality, i.e. reproducing offspring with a low survival potential. For this reason, natural selection in some species of birds imposes certain traits on males (most often) in order to make their survival more difficult and thus only allow the healthiest and most adaptive to survive, but also to reproduce. 

                                             

      

Additionally, by fighting between males and hitting their beaks, the casque additionally burdens the neck musculature and skeleton. In other words, during a fight, a healthier and stronger male will win or lose due to a bad diet, disease or a poor genetic predisposition by not withstanding the additional burden on his neck.

Why are male and female hornbills so different?

In most species of hornbill, males are much larger, have much more pronounced colored feathers, and a much larger horn-like growth on their beak. This difference in morphology between males and females of the same species is called sexual dimorphism. 

All these differences make the lives of the males more difficult for survival. Through a larger amount of resources that they need (food, water, nesting space), or through greater susceptibility to predators in their surroundings (through coloration and vocalization in search for females during the mating season), or through greater probability of injury during a fight between males, their lives are relatively harsher then of females. 

Bearing in mind that a male can reproduce a large number of offspring, while one female can reproduce a relatively small number of offspring (due to a limited number of egg cells), it is quite expected that males will to a greater extent take over the burden of survival than females. In this way, nature improves the conditions for selection of the healthiest, strongest and most adapted males, and thus the birth of offspring with the greatest possible potential for survival in nature, but at the same time not reducing the population size of the next generation.

                                                   

The great hornbill is a large bird with a very large bill, which bears a sizable, brightly colored, horny growth known as the casque. The body is mostly black with a white neck, wing coverts, and flight feathers.

Size : 100 to 120 cm (40 to 48 in.); 150 cm (5 ft.) wingspan; males grow larger than females

Weight: Averages 3 g (6.6 lbs.)

Diet:  Figs comprise a major part of the diet but the species also takes eggs, amphibians, reptiles, insects, mammals, and small birds.

Incubation : 25 to 40 days

Clutch Size : 1 to 2 eggs

Life Span : 35 or more years

Range : The great hornbill has a wide distribution and can be found in China, India, Nepal, Bhutan, Bangladesh Myanmar, Thailand, Laos, Vietnam, Cambodia, Malaysia, and Indonesia. The large majority of the population is found in India.

Habitat : The Great Hornbill frequents wet evergreen and mixed deciduous forests, ranging out into open deciduous areas to visit fruit trees and ascending slopes to at least 1,560 m (5118 ft) in southern India and up to 2,000 m (6562 ft) in Thailand.

Population Global: Due to consistent population densities within protected areas in west and northeast India and Thailand, their population is currently estimated at 23,000 to 71,000 individuals. This roughly equates to 13,000 to 27,000 mature individuals.

Status IUCN: Near Threaten

                                                 

The magnificent hornbills of Sarawak

Females are smaller than males and have bluish-white instead of red eyes, although the orbital skin is pinkish. Like other hornbills, they have prominent "eyelashes".

The most prominent feature of the hornbill is the bright yellow and black casque on top of its massive bill. The casque appears U-shaped when viewed from the front, and the top is concave, with two ridges along the sides that form points in the front, whence the Latin species epithet bicornis (two-horned). The back of the casque is reddish in females, while the underside of the front and back of the casque is black in males.

                                                       

The casque is hollow and serves no known purpose, although it is thought to be the result of sexual selection. Male hornbills indulge in aerial casque butting, with birds striking each other in flight. The male spreads the preen gland secretion, which is yellow, onto the primary feathers and bill to give them the bright yellow colour. The commissure of the beak is black and has a serrated edge which becomes worn with age.

                                                 

The wing beats are heavy, and the sound produced by birds in flight can be heard from a distance. This sound has been likened to the puffing of a steam locomotive starting up. The flight involves stiff flaps followed by glides with the fingers splayed and upcurled.