Successful captive breeding of Mitchell's water monitor, Varanus mitchelli (Mertens 1958), at Perth Zoo.

Mitchell's water monitors (Varanus mitchelli) have been maintained on display at Perth Zoo since 1997. They are generally a timid species but have been maintained and bred in a mixed species water feature exhibit. In this article we describe their captive management and behavior with an insight into their reproductive biology. Between 2002 and 2005, 11 clutches were laid ranging from 13 to 27 (X = 20) eggs from one female. Egg size ranged between 3.00 and 6.08 g (X = 4.77 g) in weight, 22.8 and 31.9 mm (X = 28.3 mm) in length, and 11.1 and 19.3 mm (X = 17.1 mm) in width. Oviposition included double and triple clutches ranging between 41 and 60 days apart (X = 48 days), events n = 6. Four clutches were incubated at three different temperatures and hatchlings emerged after 157-289 days. The weight of the hatchlings ranged between 2.60 and 4.52 g (X = 4.34 g). Total length ranged between 140.1 and 178.0 mm (X = 165.9 mm) and snout-vent length ranged from 53.8 to 70.0 (X = 64.4 mm). Juvenile growth and development information is presented from hatching through to approximately 3 years of age.