Climatic determinants of the reproductive timing in the Asian house gecko, Hemidactylus frenatus Duméril and Bibron (Gekkonidae)

Small ectotherms are strongly affected by their immediate environment and so respond sensitively to climate. The climatic determinants of reproductive timing in a reptile species may, ultimately, determine the geographic range of that species, and these determinants are, thus, of particular interest when the species is invasive. Here we examine climatic correlates of reproductive timing in the invasive asian house gecko, Hemidactylus frenatus, across two sites representing its long-established and recently-introduced range. We collected data on the proportion of gravid females in Darwin, Australia (its introduced range) over two years, and compared that with previously published data from the gecko's long-established range (in Bandung, Java, Indonesia). Our analysis suggests strong site differences in the response of this species' reproductive timing to climate. In both sites, high minimum monthly temperatures were strongly associated with increased numbers of gravid females, but the effects of other variables (maximum temperature and moisture availability) were more site dependent. These site differences may be due to many factors, including plasticity, and evolution, which we are unable to elucidate here. The differences between sites in the response to climatic variables, however, suggests it may be difficult to determine the climatic limits to this species' range based on a simple analysis of climate