Nesting, Incubation and Hatchling Growth in Captive Kreffts Tortoise, Emydura-Krefftii

Abstract

Krefft's tortoise has been maintained at the Royal Melbourne Zoo since 1972. From 1978 to 1983 inclusive, 24 clutches of eggs were laid. For 20 clutches, mean clutch size was 17 eggs, mean egg weight was 7.9 g, mean egg dimensions were 35 x 20 mm, and pipping commenced after 46 days at a constant incubation temperature of 30°C. Internesting periods were 30-51 days, with one female laying four clutches in one season. Hatchling growth was monitored, and young attained a mean weight of 53 g and mean carapace length of 73 mm after 12 months. Development of the embryonic attachment zone was also monitored. The results gained are compared with published data from two populations of wild tortoises.