I have never encountered this diminutive monitor lizard active above ground; the vast majority of specimens were collected in pit traps. During August 1967, two were dug up in shallow burrows (one of these must have been active immediately prior to being exhumed as there were crisp fresh tail lash marks at the burrow's entrance and the lizard had a body temperature of 35.4o C, ten degrees above ambient air temperature). Several specimens were trapped at Red Sands during 1989-91 and a few more were captured in 1995. Another 30 specimens were trapped during Novembers and Decembers of 1992 and 1995 on the B-area, which is a flat sandplain covered with large, long unburned, clumps of spinifex, possibly the preferred habitat of brevicauda. One female weighing 9.1 gm contained an adult 1.5 ml Ctenotus calurus; this prey item constituted 16.5% of the brevicauda's body weight.
The smallest male with enlarged testes was 82 mm SVL
and the smallest gravid female was 94 mm SVL.
World's smallest monitor lizard, actual size,--->
a neonate Varanus brevicauda (SVL = 52 mm,
wt 1.4 gms).
I pit trapped hatchlings during January and February 1996 (SVLs ranged from 52-53 mm; weights from 1.3 to 1.4 grams). The typical monitor lizard threat posture and behaviour has been conserved in the evolution of these tiny monitors, which hiss and lunge with throat inflated as if they are a serious threat.
Pianka, E. R. 1970. Notes on Varanus brevicauda. Western Australian Naturalist 11: 113-116. Download pdf
Pianka, E. R. 1982. Observations on the ecology of Varanus in the Great Victoria desert. Western Australian Naturalist 15: 37-44. Download pdf
Pianka, E. R. 1986. Ecology and Natural History of Desert Lizards. Analyses of the Ecological Niche and Community Structure. Princeton University Press, Princeton, New Jersey.
Pianka, E. R. 1994. Comparative ecology of Varanus in the Great Victoria desert. Australian Journal of Ecology 19: 395-408. Download pdf.
King, D. R. and E. R. Pianka. 2007. Ecology of the Pygmy Monitor Varanus brevicauda in Western Australia. Third multidisciplinary world conference on monitor lizards, Alexander Koenig Museum, Bonn, Germany. Mertensiella 16: 304-311. Download pdf
To read about other Varanus in the Great Victoria desert of Western Australia, click Desert Varanus.