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African Hornbills

Overview

Hornbills are a family of birds in the order Bucerotiformes. Species range from South Africa through to India and east to the Solomon Islands. The name Hornbill, as well as Buceros (Greek for Cow Horn), refers to the hornlike Bill of these birds.

All species are omnivorous and monogamous. Nearly all species nest in tree hollows, although some exceptions exist. Monteiro's Hornbill (Tockus monteiri) is one such example which is a near obligate invertebrate feeder, and due to the arid climate can exist not only without access to direct sources of water for extended periods of time but will also nest in rock crevices.

Hornbills are well known for sealing their nest chamber entrance with "mud". Which is often a mixture of soil, feces, pieces of food (fruit, insects, fungus, etc...) The pair will work together to make the entrance hole small enough for the hen to squeeze in. Once inside the hen will finish sealing the entrance by herself leaving enough room for food transfer from the male only. This is dirty work, and in most hornbill species the hen will molt her flight feathers while in the nest chamber. The cock will then feed the hen through the slit during incubation and until the nestlings are beginning to feather. At which point the entrance hole will be broken and then the hen will join the cock in foraging and feeding the young.

Southern Yellow Billed Hornbill nesting chamber, with a well-constructed mud door in South Africa (Photo by Alex Jor
dan)




Currently, all species of Hornbill from Africa are not listed on C.I.T.E.S. meaning that their importation is not prohibited by the WBCA (Wild Bird Conservation Act). Currently, all Hornbill species that exist outside of Africa ARE listed under C.I.T.E.S. Over the past 15 years many African countries have closed their doors for exports, and in that short period of time species which were imported into the U.S. have been lost or nearly lost to aviculture. These days once available species like Jackson's, Eastern Yellow-Billed, Tanzanian Red Billed are effectively gone.

This historical context demands a sense of urgency in establishing the species which are present before they are lost to aviculture in the United States. 

African Hornbill Diversity

African Hornbills are amazingly varied in form and size. From the ~100 gram Black Dwarf Hornbill (Horizocerus hartlaubi) to the Southern Ground Hornbill (Bucorvus leadbeateri) which can weight upwards of 6,000 grams! The space between these two extremes is where the bulk of diversity exists. Many species in the genus Tockus & Lophoceros occupy woodlands and grasslands, but the rainforests have a species for nearly every microhabitat. Bycanistes species often reign supreme in foraging sites with only primates competing at foraging sites. With the 2 species of Ceratogymna pushing out Bycanistes within their range for primary roosting and feeding sites. 

Below are some examples of the evolutionary variety of African Hornbills 

Two approaches to occupying the dense growth of the Central and West African Rainforest Habitats for Hornbills.

Black Dwarf Hornbill (Horizocerus hartlaubi)


Long Tailed Hornbill (Horizocerus albocristatus)

 A comparison of two species occupying the forest canopy foraging sites, where only primates and some parrots are competition for food.

Yellow-casqued hornbill (Ceratogymna elata)

Black and White Casqued Hornbill (Bycanistes subcylindricus)

There are two massive ground hornbill species, with the Southern Ground being produced in captivity in the United States in extremely limited numbers. I am unaware of any privately bred Abyssinian Ground Hornbills being produced at this time.

Southern Ground Hornbill (Bucorvus leadbeateri)

My Collection

I maintain a small collection of 4 species of smaller African hornbill. Each is highlighted below.

The care for all 4 species is more or less the same. With minor differences being a preference towards one food option over another. The smaller billed Red Bills, for instance, will ignore larger prey items, whereas the Von der Decken's and Yellow Bills will happily take larger prey items such as fish or defrosted rodents.
Diet

I provide 3 primary food groupings daily.
1.) Dry food: Mazuri softbills pellets are available at all times. This is a low iron food item. Hornbills, as with many softbills are prone to iron storage disease.
2.) Wet Food: This is a mix of high-quality dog food (soaked in hot water to soften), fruits (non-acidic fruits such as papaya, mango, guava, lychee, blueberries, figs), frozen mixed vegetables, spring mix.
3.) Whole food items: super worms, mealworms, crickets, dubia roaches, small rodents, snails, small fish (not goldfish).

I do occasionally offer spring mix and mushrooms, which are always well received. Both food sources have iron and should be fed sparingly and dusted with calcium.

Supplementation with additional food items as well as vitamin supplements should be checked for iron content. 100ppm is an ideal maximum for any food frequently offered. The FDA offers a great resource for checking foods nutritional content. Hemochromatosis is a common issue with many "softbills".

There are 3 main ways to avoid this issue:
Limiting and avoiding iron in food.
Offering calcium-rich foods and supplementing foods with additional calcium, to impede iron absorption into the blood.
Offering tannin-rich water on occasion (generally done by offering a weak tea for their water source once per month).

In regards to tannins, it is logical that the species occupying rainforest habitats many tropical fish species also occupy would be drinking the same tannin-rich water these species thrive in. Perhaps in time, the pieces will be put together and we will have a more definitive approach to the topic. To learn more about tannins click here: https://tanninaquatics.com/blogs/the-tint-1/blabbering-on-about-bark

I generally replace the dry food daily, the wet food is fed in the morning and pulled a few hours later before it spoils. Whole food items are fed once per day during the offseason, but kept well stocked at all times during the breeding season.

Water is changed a minimum of once per day, but checked with every food change and replaced if soiled.
All dishes are sterilized daily.
Housing
These birds lack the ability to climb wire or cage bars like a Parrot. As such they require flight to move from point A to point B. Typical indoor parrot cages are completely unsuitable for housing a hornbill. A relatively small wire cage (appx 4'x2'x4') may be adequate so long as the pet bird is allowed freedom to fly daily. Whether that is contained indoors, or through free flight training is up to the individual. If the bird is not allowed free flight or indoor exercise, a cage measuring 8' long x 4' wide x 6' tall would be the minimum cage size for a single pet or a pair of the species I work with.

Climate
Climate and weather is something to keep in mind. These birds are not very cold tolerant. If you live below agricultural zone 10, you will need to provide an indoor and or heated shelter during the colder months. Unlike many Pisttacines Hornbills have a difficult time acclimating to cold weather and require basking for thermoregulation. 


Von der Decken's Hornbill (Tockus deckeni)
Cock left, Hen right.
This is an east African species from Ethiopia to Tanzania. Sexual dimorphism is apparent while young and intensifies with age. Hens have a solid black bill, whereas cocks have a bright orange pill fading to the tip



                                 
                                 


Southern Yellow Billed Hornbill (Tockus leucomelas)
Cock left, hen right. Notice the slightly larger bill of the male.
Native to southern Africa and nearly endemic to the dry savannas of southern Africa, where they can be found across all longitudes, from Angola and Namibia in the west to Mozambique and KwaZulu-Natal in the east, including Botswana, Zimbabwe and northern South Africa.

Commonly seen alongside roads, this is the Hornbill species frequently shown on social media riding on cars. This species has an interesting relationship with the dwarf mongoose. The mongoose permits the yellow bills to forage on the scraps of their foraging (insects) in exchange the hornbills provide a warning system to the mongoose of predators in the area. This is known as mutualism and very interesting behavior. 


Western Red Billed Hornbill (Tockus kempi)
Juvenile above/Adult Male Below. Note the dark base to lower mandible.


Western Red Bills are one of the few species of Hornbill currently being imported and available for a respectively low price. The wild caught birds I acquired in the fall of 2018 have acclimated well, albeit still nervous. When they arrived their condition was rough, but they have now molted and their condition is improving significantly. These birds are coming out of Senegal, and are distinct from the imports which came out of Tanzania previously and were subsequently not established. I would like to acquire another pair or two over the next couple of years before imports dry up. They are quite comical, make a very soft call which sounds pleasant. Mine have proven to be slightly more selective on the food they will take, but I suspect that has more to do with them being wild caught birds than due to any specific characteristic of the species.


                                    

North African Grey Hornbill (
Lophoceros nasutus)
The African Grey Hornbill has a massive range, occupying most of central, southern and eastern Africa. Savannahs, forests and grasslands all support this species. The Northern form is currently imported, and my pair is an established proven pair imported many years ago. The southern form has a slightly more colorful bill, but I am unaware of their current captive situation. These are a medium sized hornbill with a calm disposition and make a wonderful pet.