Sexual Dimorphism, Diet, and Reproduction in the Swamp Skink, Egernia coventryi

Abstract

The Swamp Skink, Egernia coventryi, is an uncommon species that inhabits wetlands and swampy heaths in predominantly coastal regions of southeastern Australia. We examined museum specimens to quantify the diet, reproduction, and sexual dimorphism of E. coventryi. The mean SVL of both adult males and females was 85-86 mm, and individuals attain sexual maturity at about 72-74 mm SVL. Although the sexes did not differ in body size (SVL), males have longer and broader heads than females, both in terms of absolute head size and head size relative to body size. Females ovulate in September and October with parturition occurring in late January or early February. However, not all adult females collected during the breeding season were pregnant, suggesting that female E. coventryi may not always breed annually. Litter size in E. coventryi ranged from 1-4, with a mean litter size of 2.6. Egernia coventryi is omnivorous and a largely opportunistic forager, with spiders (found in 16 of 47 individuals, 34%), beetles (26%), lepidopterans (17%), ants (11%), hemipterans (9%) and aquatic amphipods (9%) the most common animal prey items found in the alimentary canals of individuals. However, plant materials (e.g., fruits/berries, seeds, other vegetation) also were found in the stomachs of the majority of the specimens (66%). Sloughed skin (26%) and the tail fragment of another E. coventryi were found in the alimentary tracts of preserved specimens. The majority of specimens (76%) were infested with endoparasites, with one specimen containing 130 nematodes, although the mean number of nematodes per specimen was 8.87. Show more