Black Headed Monitor

One of two subspecies, this one Varanus tristis tristis being in the drier parts of Western Australia shelters in Eucalyptus trees where they can move directly from tree to tree exploring hollows and burrows in search of food. They are most active during the spring and often cover over a kilometer per day accumulating large fat reserves to sustain them through six or seven months of inactivity during the winter. Although I saw this one at the bottom of the page in August.

The other subspecies is called the Freckled Monitor Varanus tristis orientalis

This photograph was taken at the Armadale Reptile Centre. Here you can see it moulting or sloughing.

This monitor is sometimes called a Racehorse goanna but this name is given to a few Western Australian monitors.

Mating occurs in November, when pairs of lizards have been found sharing the same tree. Large numbers (6-11 but sometimes as many as 17).

Small eggs are laid in December which hatch in February or March, when the adults are relatively inactive.

These are the tracks of the Black-headed monitor photographed at Halls Creek.

Photographed at Halls Creek Motel in the Kimberley in August as it walked quickly past me.

This one here at Halls Creek was foraging along the ground sometimes with its tail bent up in the air and flicking its long tongue.

The Black-headed monitors body temperature can be as high as 47.3C recorded in the wild (Pianka 1994)! The ability to tolerate such high temperatures is very rare in the animal kingdom. In general however, these goannas maintain lower active body temperatures than other desert goannas. The amount of black colouration probably has a major effect on the speed that this species can heat up.

Go Here to see our video of this monitor as it came towards me, I was hoping it wasn't going to mistake me for a tree.

What do they eat?

Their main prey is other goannas, skinks and gecko's. They often swallow large dragons over a quarter of their own body weight and are able to swallow the heavily protected thorny devil. They also raid birds nests for eggs and fledglings and collect a variety of invertebrates including beetles and ants.

This Gilberts Water Dragon was found where this Black Headed monitor was found in Halls Creek. Go Here to see our page on this dragon.

Text;
http://mampam.50megs.com/monitors/tristis.html