Tiliqua rugosa are viviparous, typically producing 1 to 2 young, although triplets do occasionaly occur. A type of placenta very much like that of primitive mammals is formed between the mother and young. This permits the exchange of food and waste between the mother and the developing embryos (Cogger, 1967). Young are produced in late March or early April of each year after approximately 5 months of gestation. Young lizards weigh about 60 to 140 grams at birth and have a relative clutch mass (as a percentage of female gravid mass) of about 28%. The small litter size of young but the large size of individuals is believed to reduce risk of predation and aid in the potential survival through the oncoming winter months (Vitt and Pianka, 1994). Copulation is usually observed around late October or early November and is typically over with very quickly. There is a great deal of evidence that shingle backs are monogamous (see behavior section).