Growing Up in a Changing Climate: How Temperature Affects the Development of Morphological, Behavioral and Physiological Traits of a Marsupial Mammal.

Clare Stawski,Fritz Geiser

doi:10.3389/fphys.2020.00049

Clare Stawski, Fritz Geiser

Open Access

https://doi.org/10.3389/fphys.2020.00049

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Abstract

Climate change is likely to affect many mammalian phenotypes, yet little is known whether and how phenotypic plasticity is involved in responding to thermal challenges during mammalian development. We investigated the effect of continuous cold or warm exposure during development on morphological, behavioral, and functional variables of yellow-footed antechinus (Antechinus flavipes), a semelparous Australian marsupial mammal. Captive-bred young were exposed to two ambient temperatures (Ta), cold (17°C) or warm (25°C), once weaned. Treatments were reversed and metabolic rate (MR) measurements repeated after 2 months. We measured body mass weekly, activity continuously, and MRs over a range of Ta once they were adults. Growth rate was similar in both groups, but was faster in males. Antechinus in the warm group were initially more active than the cold group and decreased activity when exposed to cold, whereas the cold group increased activity when exposed to warm. Interestingly, females changed their night-time activity when Ta was changed, whereas males changed their daytime activity. MRs were originally lower in the warm group in comparison to the cold group for both sexes and increased slightly for females, but not for males, after being exposed to cold. After exposure to warm Ta, the MRs of the cold group decreased significantly over the entire Ta-range for both sexes. Our results reveal that temperatures experienced during development can influence behavioral and physiological traits in antechinus. Such phenotypic plasticity is vital for a species that within 1 year is dependent on a single breeding event and experiences a complete population turnover.

Highlights

Ambient temperature (Ta) is known to influence critical developmental stages of many organisms
How different Ta affect growth rates during development in endotherms is poorly understood, for many organisms cold environments can often select for larger body sizes, known as Bergmann’s rule (Bergmann, 1847; Meiri and Dayan, 2003; Angilletta, 2004)
It may be that the activity level of an individual during development as a result of the Ta can impact on their adult activity levels, and on their resulting growth rates and metabolic rates (MRs)

Summary

Introduction

Ambient temperature (Ta) is known to influence critical developmental stages of many organisms. Traits affected by Ta during development range from body size to sex to energetics and, importantly, adult phenotypes are a result of the environment in which the individual developed (Scharloo, 1989; Pigliucci et al, 1996). Little is known about how species respond morphologically, Effect of Temperature on Development behaviorally and physiologically during development to new thermal challenges and such data are lacking for endotherms (Williams et al, 2008; Huey et al, 2012). Temperature effects on growth rates in ectotherms are relatively well understood. How different Ta affect growth rates during development in endotherms is poorly understood, for many organisms cold environments can often select for larger body sizes, known as Bergmann’s rule (Bergmann, 1847; Meiri and Dayan, 2003; Angilletta, 2004). It may be that the activity level of an individual during development as a result of the Ta can impact on their adult activity levels, and on their resulting growth rates and metabolic rates (MRs)

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