A giraffe stands stock still. Tall and statuesque, its long neck and limbs are completely motionless. And yet somehow its skin appears to be on the move.
ook closer. Use your binoculars, in fact. The towering mammal is not merely twitching its hide. A posse of brown birds are clambering like feathered abseilers over its leggy contours. Look closer – zoom in on the birds’ colourful bills – and you will see that each is in constant frenetic action, sifting and probing through the giraffe’s coarse hair as its hops and flutters from ear to elbow and mouth to mane.
These birds are oxpeckers, of course. There are two species, the red-billed (Buphagus erythrorhynchus) and the yellow-billed (Buphagus africanus), which are best told apart – as their names suggest – by bill colour. Related to starlings, both occur only in sub-Saharan Africa where they prefer bush and savannah habitats. In truth, however, their habitat is not so much the landscape as the large mammals that inhabit it. Any medium to large herbivore will suffice, from giants such as giraffe, rhino and buffalo to antelope such as impala. It is on these hosts that they live out most of lives, feeding, roosting, mating and even gathering nest material in the form of hair.
You’d think it would drive the animals nuts. Having half a dozen flapping, pecking, probing birds crawling over you all day long can’t be comfortable. But most hosts tolerate the intrusion – and with good reason. Large mammals living in African grasslands are infested with ticks and other skin parasites. These offer a rich food source to anything with the ingenuity to get at them. This arrangement seems a perfect example of what scientists call ‘mutualism’: the birds get a free meal and, in return, the host gets a personal grooming service. It’s a win-win.
Perhaps. But studies have suggested that this arrangement may be more one-sided than it appears. Watch for a while and you’ll see that oxpeckers devote much of their attention to any wounds they can find on their host’s hide. Indeed, their constant probing serves to keep open wounds that would otherwise heal. You see, as well as eating parasites, oxpeckers also have a taste for blood. Many of the engorged ticks they find have already filled up on the stuff – and once they have removed these, they may go straight to the source.
The scientific jury is thus still out on how much the host animals benefit from their avian hangers-on. Do the birds get rid of harmful parasites or are they harmful parasites themselves? One study has shown that impala receiving attention from oxpeckers tend to groom themselves less that those that aren’t. And zebra do appear actively to assist the oxpeckers by lifting their tails. Only elephants are truly intolerant, swatting the birds away with an irritated trunk.
Either way, people walking in big game country often have cause to be grateful to oxpeckers. The birds’ rattling alarm calls can be a helpful warning of something big and potentially belligerent lurking nearby. And if you find yourself covered in ticks – well, just try standing still for a while in the bush. Who knows – you might just get a little help from our feathered friends.
To get the best out of your wildlife or safari experience, Travel Africa encourages the use of a good quality binocular. To further enhance the experience and capture great memories, take an iPhone adapter to connect your iPhone to your binocular.
This column is sponsored by Swarovski Optik, the premier range of optics for wildlife in glorious close-up. To see their full range visit www.swarovskioptik.com
Mike Unwin is an award-winning travel writer and author who has an insatiable fascination with wildlife and animal behaviour.