Reptile of the sunny season

Sabi Sand | March 2020

Summer sure is the season of abundance. It is quite remarkable what rain and an extra hour or two of sunlight can do. Trees boast their best green leaves while flowers show their true colours in competition for the pollinator’s attention.

One of these sun-loving creatures is the rock monitor (Varanus albigularis). The warmth of the sun’s rays super-charge this reptilian into a formidable predator of the grasslands. Using its excellent sense of smell, the rock monitor gathers scent particles using its forked tongue which is then analysed by the Jacobson’s organ in the roof of the mouth. Their diet is varied from insects, eggs, birds and even small mammals.

On one hot February morning while watching birds in a marula tree above us, we heard a distinctive crunching sound. Golden, our tracker, then noticed a rock monitor lizard at the base of a termite mound feeding on a giant land snail. The snail, just like the lizard, is usually seen during the wetter summer months in southern Africa. On this occasion it would be this snail’s last summer. The lizard measuring roughly four foot in length made light work of the gastropod.

What fascinated us even more is that the lizard ate every part of the snail, including its hard shell. This is known as durophagy. For this rock monitor the shell has valuable minerals such as calcium, if this was a female rock monitor this would aid in egg production ensuring the eggs develop properly and are thick enough to protect the developing embryo. We watched in awe as the lizard ensured it did not leave anything to waste and eventually settled up to soak up the sun and digest its meal.