Effects of night-time warming on temperate ectotherm reproduction: potential fitness benefits of climate change for side-blotched lizards

Abstract

SUMMARYTemperate ectotherms, especially those at higher latitudes, are expected to benefit from climate warming, but few data yet exist to verify this prediction. Furthermore, most previous studies on the effects of climate change utilized a model of uniform annual change, which assumes that temperature increases are symmetric on diurnal or seasonal time scales. In this study, we simulated observed trends in the asymmetric alteration of diurnal temperature range by increasing night-time temperatures experienced by female lizards during their ovarian cycle as well as by the resulting eggs during their incubation. We found that higher night-time temperatures during the ovarian cycle increased the probability of reproductive success and decreased the duration of the reproductive cycle, but did not affect embryo stage or size at oviposition, clutch size, egg mass or relative clutch mass. Furthermore, higher incubation temperatures increased hatchling size and decreased incubation period but had no effect on incubation success. Subsequent hatchlings were more likely to survive winter if they hatched earlier, though our sample size of hatchlings was relatively small. These findings indicate that higher night-time temperatures mainly affect rate processes and that certain aspects of life history are less directly temperature dependent. As our findings confirm that climate warming is likely to increase the rate of development as well as advance reproductive phenology, we predict that warmer nights during the breeding season will increase reproductive output as well as subsequent survival in many temperate ectotherms, both of which should have positive fitness effects. Supplementary material available online at

Long‐term changes in abundances of Sonoran Desert lizards reveal complex responses to climatic variation

“…Rising T min and T e can increase energetic costs of maintenance metabolism if inactive, nonforaging individuals experience physiologically costly body temperatures (Brischoux, Dupou e, Lourdais, & Angelier, 2016;Clarke & Zani, 2012;Patterson & Davies, 1978;Zani, 2008;Zani et al, 2012). Despite the relative novelty of these patterns, core aspects of lizard behavior and thermal biology suggest a mechanism we proposed is plausible.…”

Brown adipose tissue: physiological function and evolutionary significance

“…In fact, some enzymatic isoforms in rat testes display optimal kinetics of 32 °C (Ewing and Schanbacher 1970). The temperature dependence for hatching speed and reproductive success is similar in reptile females (Clarke and Zani 2012;Amiel and Shine 2012;Bell et al 2013). Taken together, good arguments can be forwarded that the lesser hedgehog tenrec supports a concept linking evolution of eutherian endothermy to BAT.…”

Evidence of current impact of climate change on life: a walk from genes to the biosphere

“…In amphibians and birds, advanced periods of breeding and oviposition in response to warming have been observed (Beebee, ; Crick et al ., ; Schaefer et al ., ; Potti, ). An increase in reproductive success has been observed in reptiles (Zhang et al ., ; Takeda et al ., ; Clarke & Zani, ) and is frequently accompanied by an advance in the period of oviposition (Zhang et al ., ). Drought can have the opposite phenological effect to that of warming, for example, it has delayed phenological phases in butterflies of the Mediterranean basin (Stefanescu et al ., ).…”