Varanus gilleni is a tree climbing monitor from the subgenera Odatria. The color on the back is brownish, at the sides tending to gray. A number of narrow horizontal dark reddish brown stripes are seen over the back. Pale gray scales are frequently scattered within these stribes. Head and limbs are grayish brown with deep brown spots and a reticulated pattern. The tail is gray with some deep brown scales which can form narrow bands. In the back half these spots form more lengthways stripes. The coloration of the lower side is white with numerous gray spots quite particularly on the throat. The head scales are small, irregular and smooth. 90-125 scale rows are around midbody. The nostril is situated at the side, it is approximately situated in the middle between tip of the snout and the eye. The tail is more or less round in the diameter without a keel. The length is approximately 1.4 times the SVL. The total length is up to 35 cm.

Varanus gilleni from different localities

The distribution of V. gilleni extends from the Eighty Mile Beach in Western Australia, over the Center to the border of Queensland. The distribution goes down to Quorn in South Australia. Like V. caudolineatus, on which it strongly reminds because of its behavior, but from whome it is clearly distinguished by size, this monitor species is very strongly bound to the existence of the desert oak (Casuarinae). You can find V. gilleni under loose bark (MERTENS 1942d, 1958, KEAST 1959, WORRELL 1966, BUSTARD 1968, SWANSON 1976, WILSON & KNOWLES 1988, HOSER 1989, STORR 1980, STORR et al. 1983b, COGGER 1992, EHMANN 1992). There it hunts for insects, small geckos and skinke (LOSOS & GREENE 1988).

The captive husbandry of this monitor species is fairly easy. We offer one pair an enclosure, which was constructed for a tree climber, it means, that the height is more important than the base. Some medium sized trunks with loose bark (if possible), some pieces of cork, and a dish with fresh water completes the setup. However, V. gilleni does not live as secret as its small relatives. You can keep a pair together in the enclosure yearround. An occasional separation during the Australian winter, which is in the time between May and September, is advisable here also.
The breeding up to the F2 generation in Germany of this monitors is already reported (HORN 1978, EIDENMÜLLER 1994, EIDENMÜLLER & WICKER 1996, POLLECK 2001). Matings show the typical behavioral pattern of monitors. The animals are not aggressive against each other. But sometimes it is good to separate the animals occasionally. You should remove the male from the enclosure also before the female starts its egg-laying to give her the possibility to deposit the eggs without any stress. The clutch size of V. gilleni is between 2 and 4 eggs.
The young animals hatch after an incubation period of approx. 100 days at temperatures between 27 and 29°C. The rearing does not cause any problems. As the first food we offer small house cricket, crickets, grass hoppers, and cockroaches which always are dusted with vitamin mineral powder. You can easily raise the offspring of one clutch together within the first months. As soon as you can distinguish the sexes or if difficulties appear during feeding, the animals should be separated immediately and should be raised in separate small enclosures. You will avoids losses during bitings or stress.