Nest site choice compensates for climate effects on sex ratios in a lizard with environmental sex determination

By J. Doody, Enzo Guarino, Arthur Georges, B. Corey, G. Murray, M. Ewert. Evolutionary Ecology, 2006

229 citations recorded by the source corpus.

Theoretical models suggest that in changing environments natural selection on two traits, maternal nesting behaviour and pivotal temperatures (those that divide the sexes) is important for maintaining viable offspring sex ratios in species with environmental sex determination (ESD). Empirical evidence, however, is lacking. In this paper, we provide such evidence from a study of clinal variation in four sex-determining traits (maternal nesting behaviour, pivotal temperatures, nesting phenology, and nest depth) in Physignathus lesueurii, a wide-ranging ESD lizard inhabiting eastern Australia. Despite marked differences in air and soil temperatures across our five study sites spanning 19° latitude and 1200 m in elevation, nest temperatures did not differ significantly among sites. Lizards compensated for climatic differences chiefly by selecting more open nest sites with higher incident radiation at cooler sites. Clinal variation in the onset of nesting also compensated for climatic differences, but to a lesser extent. There was no evidence of compensation through pivotal temperatures or nest depth. More broadly, our results extend to the egg stage the life history prediction that behaviour is the chief compensatory mechanism for climatic differences experienced by species spanning environmental extremes. Furthermore, our study was unique in revealing that nest site choice influenced mainly the daily range in nest temperatures, rather than mean temperatures, in a shallow-nesting reptile. Finally, indirect evidence suggests that the cue used by nesting lizards was radiation or temperature (through basking or assessing substrate temperatures), not visual detection of canopy openness. We conclude that maternal nesting behaviour and nesting phenology are traits subject to sex ratio selection in P. lesueurii, and thus, must be considered among the repertoire of ESD species for responding to climate change.

Subfields: Ecology, Evolution, Behavior and Systematics, Global and Planetary Change, Nature and Landscape Conservation

View Paper: https://www.semanticscholar.org/paper/17e7c6d2ec28af32f8f5abcc6c2edb726dd99e53

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Citations in the corpus

Predicting organismal vulnerability to climate warming: roles of behaviour, physiology and adaptation (2012, background): “For example, a female can control the thermal conditions her eggs will experience simply by altering the depth of her nest or its shading [127,161,168,169], by changing season of laying [170,171] or by using buffered microhabitats such as termite mounds [172] or transpiring leaves [166].”
Impacts of climate change on the amphibians and reptiles of Southeast Asia (2010, background): “With less precipitation or with extended droughts, eggs and tadpoles will be vulnerable to mortality from drying ( Donnelly and Crump 1998 ).”
A potential tool to mitigate the impacts of climate change to the caribbean leatherback sea turtle (2012, background): “…global warming is to keep the temperature of translocated nests around the pivotal temperature (29.5 °C) for the species (Binckley et al., 1998; van de Merwe et al., 2005), but not much lower to ensure that selection for alteration of the pivotal temperature is not prevented (Doody et al., 2006).”
Evolution and behavioural responses to human-induced rapid environmental change (2011, background): “Another point to consider with this type of learning is that while it allows for the recognition of novel stimuli, it does not necessarily provide any education on how to respond to them (Sih et al. 2010).”