30 Interesting Facts About Hornbills

1. Hornbills are tropical birds, named after their strange beaks. There are nearly 60 species of hornbills. They are present in the tropical areas of Africa, Asia, and Oceania.
2. Hornbills have extra long, curved bills. However, the most distinguishing feature in several species is the casque (helmet) above their beak. Some species, such as the red-billed hornbill and the yellow-billed hornbill, are without casques. 
3. Unlike other birds with three-lobed kidneys, hornbills have two-lobed kidneys. Their kidneys contain anterior and exterior lobes but no middle lobe. Researchers think this kidney enables these birds to process water efficiently. The efficient water extraction makes their feces drier than other birds. Hornbills use this dung-like material to build their nests. (Source)
4. The bill and casque in hornbills apply much pressure on the neck. Therefore, their first two neck vertebrae join together to support this weight.
5. Like many other birds, the long beaks of hornbills assist them in getting rid of extra heat in warm climates. The thermoregulation of hornbill beaks starts functioning at air temperatures above 30 C. However, their heat loss mechanism is less efficient than that of toucans due to relatively shorter and harder beaks. (Source)
6. Several hornbill species have bright orange-red beaks and casques. It happens due to secretion from a gland. The bird rubs the beak beneath its tail, stimulating a gland that releases orange-red oil.
7. Yellow-casqued hornbills can distinguish between different calls of Diana monkeys. The alarm call of these primates is separate for crowned eagles and leopards. Hornbills face danger from eagles and respond only to monkeys’ alarms about approaching crowned eagles. These are the first birds with this feature of distinguishing between alarm calls for two different predators. (Source)
8. Southern ground hornbill is the largest, while the red-billed dwarf hornbill is the smallest among these birds. The great hornbill is the largest forest-dwelling hornbill. 

   

   Red-billed hornbills are the smallest among hornbills

   
   
9. Hornbills have binocular vision like many other birds. But unlike other bird species, the bill in hornbill comes in its field of vision and reduces the width of the binocular field. However, it assists hornbills in grasping various items on the tip of the bill accurately. (Source)
10. Most hornbills are omnivores, and eat fruits, insects, and small animals. Fig is the favorite food for most forest-dwelling hornbills. These birds don't chew their food and instead swallow it entirely. They only eat the fleshy part of their fruits and pass whole seeds, which assists in growing new trees in forests. 
11. Forest-dwelling hornbills play a vital role in dispersing seeds of various fruits in tropical forests. Hornbills disperse seeds of nearly 750 plant species up to several kilometers away from the parent trees. It ensures the spreading of seeds throughout the forest. Moreover, these birds disperse high quality seeds due to the long retention time of these seeds in their digestive system. (Source)
12. Many hornbill species are monogamous. The most prominent is the Monteiro’s hornbill of Africa, where both males and females remain strictly monogamous.
13. Hornbill habitats include forests, shrubland, savannas, and rocky areas. They build nests in trees or on rocky cliffs.
14. Toucans and hornbills have similar appearances and diets. However, both are not related, and their similarities are due to their identical environments.
15. Hoopoes and wood hoopoes are the closest relatives of hornbills. Despite shared genetics, hornbills differ from these birds in size, appearance, and habitat. However, all these birds have similarities in their nesting and diet. 
16. Male hornbills are usually bigger than females. In some species, the males are up to 66% larger than female hornbills. The casque is also larger in males than in females.
17. Casques in hornbills perform several functions. They make the calls more audible by resonating with the bird’s sound. Hornbills also use them to dig soil and peel off tree bark. Heavy casques in some species make the bills work like a hammer.
18. In all forest-dwelling hornbills, females enclose themselves inside the nest before incubation with assistance from males. The pair construct walls using mud, dung, soil, and other objects to protect females and eggs. A small hole in the wall allows the male to provide food inside the nest. The female leaves the nest after hatching eggs, but the newborns remain inside after rebuilding the wall.
19. The number of eggs is different in various hornbill species. Large birds lay one or two eggs, while smaller species can have up to seven eggs.  
20. Unlike other birds, female hornbills shed their feathers simultaneously while in the nest. However, there was a misconception that the process is the result of darkness in their nests. A recent study concludes this unique molting process is a natural behavior in hornbills and has no link to the darkness of their nest cavity. (Source)
21. Female hornbills keep the nest clean during incubation by throwing the waste outside. They use a small opening for this purpose.
22. All the hornbill species are arboreal except the two ground-dwelling hornbills. Abyssinian ground hornbill and southern ground hornbill are native to Africa. They can fly but spend most of their time on the ground. Unlike other omnivore hornbills, these birds are mainly carnivorous. Their prey also includes animals like snakes and small monkeys.
23. Hornbills form mutually beneficial relationships with other animals, particularly mongooses. They inform dwarf mongooses about any danger through an alarm call. In return, these mammals assist hornbills in finding insects by digging ground. The two animals rely so much on each other that they usually start their morning hunt together. 

    

    Hornbills have mutually-beneficial relationship with mongooses

    
    
24. Hornbills can't make their nests and need holes in old trees for nesting. Elephants and bears play a major role in providing suitable nesting places for hornbills in Asia and Africa. Elephants tear down large branches, while Asiatic bears rip open tree trunks to get honey or termites. These actions by large mammals assist hornbills in constructing their nests.
25. According to estimates, hornbills initially appeared in Africa. Some ground and grassland-dwelling species later moved to Asia. There, some of these species changed from ground to forest-dwelling hornbills. Later, one of the Asian hornbills species moved to Africa, giving rise to forest hornbills in Africa. 
26. Papuan hornbill is the only hornbill species native to the Oceania or the Australasian region. Its range is from eastern Indonesia to the Solomon Islands. These hornbills inhabit rainforests from coastal areas to hills with elevation of 1,500 m or more. 
27. Some hornbill species have eyelashes, a less common feature in birds. Unlike mammalian eyelashes, these bird eyelashes are the product of modified feathers and protect the bird’s eyes from sun and debris.
28. Various species of hornbills can live for up to 50 years. Large species, like southern ground hornbills and great hornbills, can live for 70 years, one of the longest among birds.
29. Despite their large size, hornbills pose no danger to humans. They would fly away if disturbed. Some species live near human settlements, which may look for food near households. However, they are also harmless. 
30. Southern ground hornbill produces loud booming calls that resemble a lion’s roar. These birds use their wattles to produce this sound.