Comparative Ecology of Twelve Species of Nocturnal Lizards (Gekkonidae) in the Western Australian Desert

Observations on active geckos during their natural period of nocturnal activity allow comparison of many aspects of the ecologies of 12 species, including habitat and microhabitat requirements, diets, daily and seasonal patterns of activity, body temperature relationships, reproduction, predation and broken tail frequencies. Because as many as nine species, including five congeneric Diplodactylus, occur together on a single study site, emphasis is placed upon ecological differences that might reduce competition and allow coexistence of such a diversity of nocturnal species. Only slight differences in temporal patterns of activity are evident. However, foods eaten as well as habitats and microhabitats exploited differ strikingly among these gekkonids. Larger species tend to eat larger prey than smaller species. Three species are food specialists, eating essentially nothing but termites. Three others are distinctly arboreal, with the majority of specimens first sighted off the ground. Two species are semi-arboreal, one of which is restricted almost entirely to Triodia grass tussocks. Due to clear-cut differences in habitat requirements, three large terrestrial species of Nephrurus are always allopatric; one is restricted to sandridges, another to sandplain-Triodia habitats, and still another to shrub-Acacia habitats. In general, sympatric species pairs with high dietary overlap tend to overlap relatively little in microhabitat and vice versa.