Reproductive ecology of the Mountain Dragon, Rankinia (Tympanocryptis) diemensis (Reptilia: Squamata: Agamidae) in Tasmania

Abstract

The mountain dragon, Rankinta (7ympanocryptis) diemensis (Gray, 1841), is the only member of the Agamidae in Tasmania. It occurs in some of the coldest regions occupied by any dragon in Australia, and is found in a variety of habitats ranging from coastal heath to alpine scrub. This paper examines the reproductive ecology of R. diemensis in the most southerly range of its distribution, providing baseline data on timing of reproductive events, reproductive cycles, nesting behaviour and ovipositioning, clutch characteristics and incubation conditions. Winter torpor lasts approximately seven months with males emerging in early September and spermatogenesis occurring from September-November. Females emerge later, with vitellogenesis occurring from September-December. Gravid females may be found between October and January, but females are non-vitellogenic from late December until the following season. The first clutch is typically laid from October--December, with a variable clutch size (2-11 eggs). Females store sperm and a second clutch may be laid five weeks after the first. Eggs incubated in artificial enclosures at low altitude hatched after 72--106 days, after experiencing an average daily temperature of 19°-22°C, and a range of 50-39°C.