Southern Yellow-Billed Hornbill. Photo by Caroline Foster.
By Caroline Foster, Carleton College
For fans of the Lion King, you will already be very familiar with one famous little hornbill named Zazu. The real bird itself may not be as eloquent or blue but is just as amusing. While in the field, we have become familiar with four species of hornbill seen: the southern red-billed hornbill (Tockus erythrorhynchus), the southern yellow-billed hornbill (Tockus leucomelas), the African gray billed hornbill (Tockus nasutus), and the ground hornbill (Bucorvus leadbeateri). None of these species are what you would call pretty but spectacular might be a more suitable adjective for the bird with their oversized beaks and amusing flight pattern.
The red billed horn bill, as you might guess, has a red bill and is actually the smallest of the horn bill species (40 cm from end of tail feathers to tip of beak). They feed mainly on insects, some small mammals, and rarely fruit and nuts. Very similar to the red bills are the southern yellow billed hornbill which – no surprise, has a yellow bill. They are slightly bigger than the red billed hornbill but eat almost the same diet. Both the red-billed and yellow-billed hornbills make a ‘wukwukuk, wukwukuk, wurk, wurk’ song. These two species are also known for following mongooses in order to catch small prey that the mongoose may miss. They have even been known to wait outside the mongoose’s burrows in anticipation of a hunting trip.
Red-billed Hornbill. Photo by Addison Spitzer.
The African gray billed hornbill has more pronounced differences with a much less colorful appearance and also what is called a casque on their bill. The grey hornbill’s song sounds like a melancholic ‘phee, phephee, phee, pheeoo, pheeo’.
The ground hornbill is the most unique of all four and is also the most threatened. It oddly reminds me of a dodo bird although instead of being gray, they are black with a bright red beak. They are fairly large birds (90 cm from beak to tail) and in general walk slowly looking for food. The ground hornbill will occasionally be frightened into flight but are a primarily terrestrial bird. Their call is a deep booming ‘oomph, oomph-oomph’. They are one of the 15 ‘Birds of Concern’ here in Botswana.
All hornbills mate monogamously and can usually be found in pairs or small flocks. What is truly special about the hornbills is how they lay their eggs. The couple finds a hollow, in a tree or a log. They then start to build a nest in the hole. Eventually the female sets herself in the hole and the male shuts off the exit with mud and sticks leaving only a small hole for him to feed his mate and for the female to use as a bathroom (they like to keep things clean). The female will stay in the hole to lay, incubate, and initially raise the chicks. The male brings the female and chicks food throughout this process. The ground hornbill specifically hatches 2 eggs. The first hatchling is the one to survive but the second hatchling dies of starvation in about a week.
African gray billed hornbill. Photo by Addison Spitzer
Like many other bird species, hornbills are known for ‘shadow-boxing’. This is when a bird sees a reflection of itself in for example the window of car and begins to attack it’s reflection. The reason it attacks is because the bird sees its ‘shadow’ as a threat to its territory. Unfortunately, ground hornbills have actually been persecuted for this behavior because they have been known to break the windows of cars.
The hornbill has what is called a ‘bounding flight’ pattern. While in flight they will close their wings completely in order to save energy rather than keeping them open and continuously flapping. This creates what appears to us as a flap-flap glide look.
Although these birds do not have the same colorful beauty as the lilac breasted roller (Coracias caudatus) or the southern carmine bee-eater (Merops nubicoides), they have become one of my favorite birds here. They are constant visitors of our campsite and are always a perk of my day, whether they are pecking on some leftover crumbs of ours or attacking their reflection in one of our cars. It’s hard not to become fond of the goofy little birds.