Tag Archives: Water monitor

The Water Monitor

Last week I wrote about the Rock Monitor and today I will chat about the Water monitor (Varanus niloticus) that is found in southern Africa.  They’re apparently called monitors because they are good at monitoring the movements of crocodiles, thus warning humans of their presence.

Water monitor

We had rather an amusing encounter with a Water monitor on a trip to Namushasha in Namibia when a helpful local guide took us to see Carmine Bee-eaters breeding in a nearby river bank.  He told us that Water monitors love to raid these deep breeding holes for eggs and we would be likely to see one.  Sure enough, as our boat glided slowly past we saw the head of a Water monitor sticking out of a hole in the river bank, but on seeing us he retreated into his dark burrow.

Peeping out of the nest

We pulled up gently to the bank and with two cameras poised, we waited while the guide prodded into the hole with a long stick.  The Water monitor shot out at such a speed that when the guide asked us if we had caught him on camera we had to laugh.  Both cameras showed a blurred tail tip in each frame – neither of us had been as fast as the monitor!

Water monitor

Water monitors are powerful swimmers and use their strong legs and tail to propel themselves through the water.  They are capable of remaining underwater for long periods of time and their favourite food is fish and crocodile eggs, although as I said earlier, they will also eat birds eggs if available.  Like the Rock Monitors they also eat snakes, rodents and other small animals.  They have powerful claws on their legs which assist them in climbing trees and digging for food or making burrows for their own eggs.  They also burrow into live termite nests to lay their eggs.  The termiites then reseal the damaged mound, which makes an ideal place for the Water monitor’s eggs to incubate and also provides some snakcs in the form of termites for the baby monitors when they hatch.  Water monitors lay up to sixty eggs.

Snoozing on a tree

These reptiles are often sold as pets, but they are quite ferocious and are something of a nuisance in our environment.  If cornered they can be dangerous as they defend themselves and their young most vigorously.  They are known to kill and eat household pets like cats and small dogs and make a huge mess when they raid refuse bins.  Many myths abound about them and they feature in African folklore and stories, especially about their tail slaps and danger to humans.

The Rock Monitor

2012 – The ‘year of the dragon’ according to Chinese astrology.  The closest thing that southern Africa has to the dragon is the Rock monitor – a distant relative of the ferocious-looking Komodo Dragon ( Varanus komodoensis) of Indonesia.  Rock monitors are ugly creatures with bulky bodies and stubby heads and look rather like lizards on steroids.  In our part of the world both Rock and Water monitors are also known as leguaans or likkewane, which is the Afrikaans name for them.

  Rock monitor

Rock monitors (Varanus albigularis) are found in central and southern Africa in savannah and semi-desert areas.  In the wild they weigh about 6-8 kgs, but if kept in captivity, with little or no exercise and food readily available, they tend to pile on the kilos and can easily reach up to 20 kgs.  They average 1.0 – 1.5 meters in length and have a life expectancy of 10 – 15 years.

Rock monitors are fierce predators and hunt both on the ground and in trees.  This one that we saw at Etosha in Namibia came off second best and had its length somewhat shortened in an unfortunate skirmish with something – possibly a competitor for food – and is missing part of its tail.

  Ouch! Where's my tail?

An interesting feature of the Rock monitor is its forked tongue, which it uses to collect odour particles from the air.  These particles are then sent to the Jacobson’s organ in the roof of its mouth for analysis on the scent of its prey.  Once it hones in on the scent, the monitor can then follow the trail to its next meal.  Prey being anything from small invertebrates to mammals, tortoises, carrion and even snakes.

  Forked tongue of the Rock monitor

Like other lizards and reptiles, monitors also shed their skin, although the Rock monitor does it in patches instead of stepping out of its old skin in one piece.  So it looks rather scruffy while this whole process is taking place.

  Shedding skin in patches

Females lay clutches of between 8 – 55 eggs in burrows.

The Water monitor (Varanus salvator), which I will blog about next week, is smaller and has a much more gentle looking face than the Rock monitor.  It is therefore easily distinguishable from its somewhat heftier relative described above.

  Water monitor