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Bird Species Spotlight: Southern Yellow-billed Hornbill

by Jake Jacoby | June 21, 2020

© Jake Jacoby

In 2017 I had the opportunity to visit the Mala Mala Game Reserve in South Africa. This reserve has been in existence since 1927 and is the largest private Big Five game reserve in South Africa. Comprising some 35,000 acres, Mala Mala shares a 12 mile unfenced border with the world-renown Kruger National Park and lies strategically sandwiched between the Kruger and the Sabi Sand Game Reserve. One of my target birds on this trip was the Southern Yellow-billed Hornbill, or as it is affectionately called “The Flying Banana.” This hornbill was also made famous by the movie “The Lion King” where its name in the movie was “Zazu.”

Southern Yellow-Billed Hornbill © Jake Jacoby

This hornbill is omnivorous (eats both plants and animals), is a medium sized bird and is characterized by a long yellow and down-curved beak. The beak is huge in comparison to its body and can account for up to 1/6th of the entire body length. The male’s beak is bigger than the females and is the only reliable way to tell the difference between the sexes. Like other hornbills, it has a long tail, long eyelashes, stubby legs and stubby toes with the front three toes fused together near the base.

Courtship Feeding Ritual © Jake Jacoby

These hornbills are almost endemic (found nowhere else) to the dry savannas of southern Africa and they live mostly in the dry, open savannas and woodlands. They are active during morning, day and evening. At night, they sleep high in a tree so they won’t be preyed upon. They are generally sedentary and will defend their territory with elaborate displays. Couples are usually monogamous and eat mostly arthropods, particularly termites, beetles, larvae, grasshoppers and caterpillars by foraging on the ground. They may also catch snakes, which they kill by bashing them against a hard surface. They swallow their prey whole, letting indigestible parts pass through their digestive system. To complete the diet, they will regularly eat berries, fruits, nuts, and eggs from other species.

They use their beaks as a pair of forceps. They will grasp their food between the tips of their beaks and then toss it back in their throat where the short, stubby tongue will assist in swallowing the food. They are also known to forage co-operatively with Dwarf Mongooses, catching prey items that the mongoose scratch up from the ground. In return, the hornbills alert the mongoose to danger from overhead raptors.

Yellow-Billed Hornbill on Ground © Jake Jacoby

But, for me, I think that the most interesting and unusual aspect of this bird is their reproduction/nesting behavior. Breeding season starts when the first autumn rain falls with the peak egg-laying between October and December. However, before the actual breeding is done, there is a courtship feeding of the female, mutual preening, copulation and prospecting of nest sites that must be done.

Once the male has mated, he will stay with his mate and establish a territory that he will defend. The nest is placed in a natural cavity in a tree, or in an abandoned woodpecker or barbet nest between 3 and 36 feet above the ground. The male will then bring bark, leaves and grass which will be placed on the bottom of the nest. During this time, the female will seal herself inside the nest by blocking the entry with a wall made from her droppings and her food remains. The male will help by bringing mud for her to work with. She uses her bill like a trowel so that the only opening left with access to the nest is a vertical slit from the top to the bottom. The male passes food through the slit with his beak. The female and chick droppings are forcibly expelled through the slit as well. This vertical slit provides good air circulation through convection and when coupled with the tree walls, provides good insulation.

Yellow-Billed Hornbill Perched © Jake Jacoby

Nests normally contain 2 to 6 eggs and take about 24 days to hatch. The eggs are white, oval and have finely pitted shells. The chicks are born naked and with pink skin. Both the chicks and the female are fed by the male bringing food back and dropping it through the slit. Most nests will also have a long escape tunnel in case a predator breaks into the nest. Hornbills are fairly large birds, and any suitable treetop hole is likely to be vulnerable to attacks from snakes, monkeys, martens and other tree-borne predators. The narrowing of the entrance to a slit effectively keeps out most predators.

Now that the female is imprisoned, she will shed all of her flight and tail feathers simultaneously and regrow them during the time she stays with the chicks. Once the chicks are half-grown, she will break out of the nest and help the male with the feeding. The chicks then rebuild the wall with their parents help and continue to be fed through the slit by both parents. Once the chicks are fully grown, they will break out of the nest and start flying. These young birds become sexually mature when they are one-year old.

All hornbills have a very unique appearance, so many cultures give them an important place in their beliefs. Some indigenous tribes revere them as sacred beings that must not be harmed. Others will hunt them for food, to use them in the confection of traditional medicine, or to use them in rituals.

About the Author

To see more of Jake's work as well as his favorite photographs check out his Flickr page.

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