Crash, slither, splash! You’re pursuing an elusive bush shrike through a riverine thicket when an unholy commotion in the undergrowth stops you in your tracks. An angry hippo, perhaps? A huge croc?
Relax. It’s only a lizard. But what a lizard! The Nile monitor (Varanus niloticus) is the biggest on the continent. Full-grown adults top two metres in length and may weigh over 15kg. That’s not big enough to devour you, admittedly, but certainly big enough to scare you witless when they beat their noisy retreat.
Once the fleeing reptile hits the water and starts swimming rapidly across the surface, you might take it for a small crocodile. But grab your binoculars and you’ll see it has a shorter nose and more serpentine tail, which – flattened like an oar – provides powerful propulsion. On land, this tail is also a formidable weapon, dealing whip-like blows in self-defence.
The Nile monitor is one of six African members of the Varanidae family, which numbers 79 species worldwide and includes Indonesia’s formidable, goat-eating Komodo dragon. In southern Africa it is known as a leguaan, an Afrikaans corruption of ‘iguana’. But monitors are not related to South America’s iguanas. Indeed, they have several features that separate them from other lizards, including beaded scales and a flickering, forked tongue. The latter works like a snake’s, detecting food by capturing scent particles and passing them through a receptor organ in the roof of the mouth.
‘Nile’ is not a particularly helpful name, as this reptile occurs across much of central and southern Africa. Though well adapted to a semi-aquatic lifestyle, it is equally effective on dry land, using powerful limbs to chase down or dig out prey, and often scaling rocks or trees to bask. It is a voracious feeder and consumes pretty much anything it can cram whole into its mouth, from fish and frogs to birds, snakes, and carrion. Individuals will operate in tandem to steal crocodile eggs, one drawing the aggression of the fearsome mother while another nips in to snatch the prize.
A female monitor produces up to 60 eggs of her own – among the most of any lizard. She generally deposits them inside a working termite mound, breaking in using her strong claws then allowing the insects to repair the damage. In this way, she provides her clutch with constant heat and humidity for incubation without having to do the work herself. The hatchlings emerge several months later, once the rains have softened the soil. They are able to fend for themselves the minute they leave the egg – which is just as well, as there are no parents around to, ahem, monitor their progress.
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 image by Mike Unwin, top image Shutterstock)
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.