BROMVOȆL
Don’t you just love the onomatopoeic Afrikaans names for some of our birds? Think of the “hoephoep” or “bromvoël” (“brom” meaning “growl” or “grumble” in English). The former is easy to guess, and the latter is, of course, also known as the Southern Ground Hornbill (Bucorvus leadbetteri).
The bromvoël has several vocalisations. Apart from the “brom”, their repertoire also includes grunting, whooping, grumbling and even roaring – depending on circumstances.
Southern ground hornbill. Photo: Africa Freak
They are striking-looking birds with all black plumage, except for the white primary flight feathers. Not that they fly a lot. As the name implies, they are primarily ground- dwelling birds. They stand more than a meter tall and weigh in at over six kg. The wingspan measures up to 1.8 m, so they are able to lift off and fly despite their size. The birds usually roost in trees and make their nests in hollows – either in trees or river banks.
There’s a bright red patch of skin over its face and throat, which makes it vaguely resemble a turkey. Male patches are all red. Females look very similar to the males, but their red throat also shows a large purple/blue patch directly beneath the beak. However, the birds only develop these colours as adults. For the first three years, the facial skin is grey or pale yellow, and the feathers are not quite black but rather dark brown.
Of course, the most striking feature of the bird is the so-called hornbill. It’s an impressively thick, slightly curved bill designed for effective foraging and capturing prey. The “horn” on top of the bill looks like an extra piece of beak attached but it’s actually a chamber that amplifies the sounds the hornbill makes — to great effect! Up close, the most noticeable feature are its beautiful pale blue eyes, complete with a set of eyelashes that would make a fashion model jealous. The eyelashes are actually modified feathers that help protect their eyes from dust and sunlight.
We call them “southern” ground hornbills as they typically roam in the southern African savannas and grasslands of Angola, Namibia, and South Africa. Their habitat is a combination of short grass in which they can forage for food and tall trees for nesting and roosting. In the wild, southern ground hornbills are skilled foragers, much like baboons. They are carnivorous and will seek out all kinds of insects, arthropods, snails, birds, frogs, and even snakes. Small rodents like leverets and mice may also be on the menu.
Southern ground hornbill female (note the blue/purple patch) with prey. Photo: SA Venues.
Ultimately their diet largely depends on where they are, what is in abundance, and whether they can catch and overpower their prey.
Southern ground hornbills live in ‘families’ or groups of ten or twelve. Like a herd of grazers, hornbill families have a dominant pair. They are monogamous, pairing for the 30 – 40 years of their lives unless their mate dies.
The dominant pair is usually the oldest – or biggest and strongest – birds. These two are the only birds that have breeding rights and they only start breeding at about ten years of age. The other birds act as a sort of support structure. They will hunt for
Despite (or perhaps because of) their complicated breeding habits they are extremely slow breeders, which makes them more vulnerable to extinction. The southern ground hornbill is what is technically referred to as an “obligate cooperative breeder.” This means that to breed successfully, a mating pair needs the assistance of at least two other birds, often juveniles. Studies have shown that when these assistants are not present, adult hornbills often fail to breed successfully. Moreover, hornbills who did not assist others with young in their early years are less likely to rear their own young and help to take care of the young.
Hornbills lay two (or sometimes three) eggs at a time in a nest in a hollow tree. The eggs are laid up to two weeks apart so that the first chick to hatch is already big and strong when the second one hatches. It is thus able to commandeer any food that the adults bring to the nest, with the result that the second chick starves to death. Sadly, not all the first-born chicks survive into adulthood either. Overall infant mortality is around 70%.
The truth is that a group of southern ground hornbills successfully raise only one chick roughly every nine years. The chick must be taught how to eat, how to kill a poisonous snake, how to avoid being stung by a scorpion, where to sleep safely at night, and how to get away from predators such as caracals. The group is so busy teaching all this to one chick that it cannot breed for several years. All the energy goes into getting the precious chick past the age of five (Homo sapiens could learn some useful lessons from them.)
This extremely low reproduction rate is one of the reasons why the number of southern ground hornbills is decreasing rapidly, with the result that they are now classified in South Africa as endangered outside of protected areas. Like so many of Africa’s beautiful creatures, the main threat to hornbills comes from us through human expansion, habitat destruction, environmental poisoning, logging, and hunting. Hornbills are often hunted by humans for traditional rituals and medicine, or killed for entering or damaging property. They are known to get so angry at their own reflections in windows that they kill the windows.
Photo: Mabula ground hornbill project
What is the future of the southern ground hornbill?
Fortunately, conservation efforts are underway, with organisations like the Mabula Ground Hornbill Project playing a leading role in protecting these beautiful birds.
Some of the most successful conservation strategies thus far have been to provide artificial nests, as their traditional breeding grounds are often damaged or have been rendered inadequate. An additional strategy is to harvest and rear the second-born chicks that would otherwise die of starvation. Once the chicks are artificially reared, the rewilding process must begin, and environmentalists can introduce them into an existing hornbill family to teach them life skills in nature.
Along with these conservation plans, there are educational and awareness programs to teach people the importance of protecting these precious birds. Environmental education is critical if South Africa’s biodiversity is to survive the human onslaught. We must understand and acknowledge – and then correct – what we did wrong in nature.
Adults teaching a hornbill chick. Photo: Times LIVE