Sexual size dimorphism and microhabitat use of the orange-tailed skink (Gongylomorphus sp.) on Flat Island, Mauritius

The Gongylomorphus skinks are an endemic genus of Mauritius and comprise two described species. Following the recent discovery of a third putative species, endemic to Flat Island, 11 km off the coast of Mauritius, this study was conducted to examine morphometrics and the pattern of microhabitat use by the species in an effort to provide effective conservation recommendations. There was a clear sexual size dimorphism with males significantly larger than females in terms of; snout-vent length, head length, head width, snout-mouth length, snout-ear length, upper and lower fore- and hind-limb lengths and fourth toe length. There was no sexual dimorphism in other measures including pelvic width, width at the base of the tail, head depth or body weight. Microhabitat use was found to be non-random with lizards occurring in areas with high humidity, high numbers of natural refugia, increased leaf litter coverage and plant species diversity, and low grass cover. We found no evidence that microhabitat use varied in relation to sex or age of lizards. The implications of these results for the conservation management of Flat Island for the orange-tail skink are discussed.