Present address: T. Langkilde, School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA
Do operational sex ratios influence sex allocation in viviparous lizards with temperature-dependent sex determination?
Article first published online: 8 MAR 2006
Journal of Evolutionary Biology
Volume 19, Issue 4, pages 1175–1182, July 2006
How to Cite
ALLSOP, D. J., WARNER, D. A., LANGKILDE, T., DU, W. and SHINE, R. (2006), Do operational sex ratios influence sex allocation in viviparous lizards with temperature-dependent sex determination?. Journal of Evolutionary Biology, 19: 1175–1182. doi: 10.1111/j.1420-9101.2006.01086.x
- Issue published online: 8 MAR 2006
- Article first published online: 8 MAR 2006
- Received 4 December 2005; revised 13 December 2005; accepted 21 December 2005
- litter sex ratio;
- maternal effects;
- sex allocation;
- sex-biased investment;
- temperature-dependent sex determination
Under certain environmental situations, selection may favour the ability of females to adjust the sex ratio of their offspring. Two recent studies have suggested that viviparous scincid lizards can modify the sex ratio of the offspring they produce in response to the operational sex ratio (OSR). Both of the species in question belong to genera that have also recently been shown to exhibit temperature-dependent sex determination (TSD). Here we test whether pregnant montane water skinks (Eulamprus tympanum) utilise TSD to select offspring sex in response to population wide imbalances in the OSR, by means of active thermoregulation. We use a combination of laboratory and field-based experiments, and conduct the first field-based test of this hypothesis by maintaining females in outdoor enclosures of varying OSR treatments throughout pregnancy. Although maternal body temperature during pregnancy was influenced by OSR, the variation in temperature was not great enough to affect litter sex ratios or any other phenotypic traits of the offspring.