Reproduction in the Tropical Australian Skink, Leiolopisma rhomboidalis

Reproductive activity of the tropical Australian skink, Leiolopisma rhomboidalis, a diurnal inhabitant of the rain forest sub- strate, was investigated over a twelve-month period between 1959-1960. The climatic conditions of the area were investigated as a possible influence on reproductive activity and were found to exhibit slight variation in temperature and day length. Although rainfall occurred in every month during the study, there was a wet and dry season. The skinks fed on the common invertebrates of the area including, in order of preference, orthopterans, beetles, and lepidopterans and their larvae. Such prey items were available at all times of the year, based on stomach contents. No data are available for hatchlings or very young individuals. Cannibalism on the young was also noted. Data based on presence of sperm, weight and tubular diameter of testis, suggests that the males are capable of reproductive activity at all times of the year, and such activity underwent no seasonal variation during the year of study. The females, based on presence of oviducal eggs and condition of secondary follicles, exhibited more seasonal variation in their reproduc- tive activity than the males. During the winter months, between June and August, they demonstrated a reduction in their reproductive activity, the exact cause of which is unknown, although lack of suf- ficient moisture for optimum egg development or to provide suitable food for the hatchlings are suggested as possible external causes.