Experimental evaluation of reproductive response to climate warming in an oviparous skink

Abstract

The impact of climate warming on organisms is increasingly being recognized. The experimental evaluation of phenotypically plastic responses to warming is a critical step in understanding the biological effects and adaptive capacity of organisms to future climate warming. Oviparous Scincella modesta live in deeply-shaded habitats and they require low optimal temperatures during embryonic development, which makes them suitable subjects for testing the effects of warming on reproduction. We raised adult females and incubated their eggs under different thermal conditions that mimicked potential climate warming. Female reproduction, embryonic development and hatchling traits were monitored to evaluate the reproductive response to warming. Experimental warming induced females to lay eggs earlier, but it did not affect the developmental stage of embryos at oviposition or the reproductive output. The high temperatures experienced by gravid females during warming treatments reduced the incubation period and increased embryonic mortality. The locomotor performance of hatchlings was not affected by the maternal thermal environment, but it was affected by the warming treatment during embryonic development. Our results suggest that climate warming might have a profound effect on fitness-relevant traits both at embryonic and post-embryonic stages in oviparous lizards.

Anticipatory parental effects in a subtropical lizard in response to experimental warming

“…The advanced timing of reproduction is largely due to rapid accumulation of energy for reproduction and endocrine control of reproductive cycling induced by temperature increase [ 53 , 63 ]. However, as found in some other lizard species [ 41 , 64 , 65 ], a climate warming scenario did not affect clutch size or egg mass in the northern grass lizard, T. septentrionalis . Several reasons may account for the insensitivity of female reproductive output to climate warming in the northern grass lizard.…”

Antioxidative Defense and Fertility Rate in the Assessment of Reprotoxicity Risk Posed by Global Warming

“…Regarding oviparous animals, many studies focused on embryonic development at oviposition. In fact, studies on gravid females during warming treatments showed a faster rate of energy accumulation and a reduced incubation period, leading to earlier oviposition and increased embryonic mortality [99,100].…”

The vulnerability of developing embryos to simulated climate warming differs between sympatric desert lizards

“…In our study, increased mean temperature reduced hatchling SVL in E. argus , but not in P. przewalskii . Similarly, hatchlings from warm incubation temperatures are smaller or lighter than those from cold incubation temperatures in some lizards including the study species (Dayananda, Gray, Pike, & Webb, ; Hao et al., ; Ma et al., ; Tang et al., ), but not in other lizards (Lu, Wang, Tang, & Du, ). High temperatures speed up the developmental rate of embryos (e.g.…”

“…In our study, increased mean temperature reduced hatchling SVL in E. argus, but not in P. przewalskii. Similarly, hatchlings from warm incubation temperatures are smaller or lighter than those from cold incubation temperatures in some lizards including the study species (Dayananda, Gray, Pike, & Webb, 2016;Hao et al, 2006;Ma et al, 2014;Tang et al, 2012), but not in other lizards (Lu, Wang, Tang, & Du, 2013 Figure 6), because low metabolic rates may reduce food intake and depress energy assimilation (Du, Yan, & Ji, 2000;Xu & Ji, 2006). As a result, the reduced growth rates could result in smaller body size of lizards before hibernation, which could be closely related to overwinter survival and fitness (e.g., Dayananda et al, 2016, Zani, 2008but see Clark & Zani, 2012;Warner & Shine, 2007).…”