Black-headed monitor

Black-headed monitor
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Family:	Varanidae
Genus:	Varanus
Subgenus:	Odatria
Species:	V. tristis
Binomial name
Varanus tristis Schlegel, 1839

The black-headed monitor (Varanus tristis) is a relatively small species of monitor lizards native to Australia. It is placed in the subgenus Odatria. Their average length is between 50 and 80 cm depending on location. V. t. tristis is the larger of two distinct subspecies, found mainly to the west of Australia. The freckled monitor (V. t. orientalis) is a smaller subspecies with a lighter, more distinct colouration confined mainly to eastern Australia. Clutch sizes range between four and 10 eggs. Males can be identified after sexual maturity (usually around two years of age) by a large cluster of spiny scales either size of the animal's vent. Female specimens lack these obvious protrusions and rarely possess more than a small number of spines only slightly larger than the surrounding scales.

Habitat and diet

This arboreal monitor lizard is usually found in grassy woodlands, where it inhabits dead hollow limbs in trees and shelters under the bark of standing trees. The black-headed monitor prefers narrow spaces in which to shelter. V. tristis preys mainly on insects, but also consumes small lizards, eggs, and rodents.