Detrimental influence on performance of high temperature incubation in a tropical reptile: is cooler better in the tropics?

Bell, Kris, Blomberg, Simon, and Schwarzkopf, Lin (2013) Detrimental influence on performance of high temperature incubation in a tropical reptile: is cooler better in the tropics? Oecologia, 171 (1). pp. 83-91.

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Abstract

Global temperatures have risen over the last century, and are forecast to continue rising. Ectotherms may be particularly sensitive to changes in thermal regimes, and tropical ectotherms are more likely than temperate species to be influenced by changes in environmental temperature, because they may have evolved narrow thermal tolerances. Keelback snakes (Tropidonophis mairii) are tropical, oviparous reptiles. To quantify the effects of temperature on the morphology and physiology of hatchling keelbacks, clutches laid by wild-caught females were split and incubated at three temperatures, reflecting the average minimum, overall average and average maximum temperatures recorded at our study site. Upon hatching, the performance of neonates was examined at all three incubation temperatures in a randomized order over consecutive days. Hatchlings from the 'hot' treatment had slower burst swim speeds and swam fewer laps than hatchlings from the cooler incubation temperatures in all three test temperatures, indicating a low thermal optimum for incubation of this tropical species. There were no significant interactions between test temperature and incubation temperature across performance variables, suggesting phenotypic differences caused by incubation temperature did not acclimate this species to post-hatching conditions. Thus, keelback embryos appear evolutionarily adapted to development at cooler temperatures (relative to what is available in their habitat). The considerable reduction in hatchling viability and performance associated with a 3.5 °C increase in incubation temperature, suggests climate change may have significant population-level effects on this species. However, the offspring of three mothers exposed to the hottest incubation temperature were apparently resilient to high temperature, suggesting that this species may respond to selection imposed by thermal regime.

Item ID: 25081
Item Type: Article (Research - C1)
ISSN: 1432-1939
Keywords: climate change, developmental acclimation, ectotherm, performance, phenotype
Date Deposited: 20 Feb 2013 09:23
FoR Codes: 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060201 Behavioural Ecology @ 50%
06 BIOLOGICAL SCIENCES > 0603 Evolutionary Biology > 060303 Biological Adaptation @ 50%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960802 Coastal and Estuarine Flora, Fauna and Biodiversity @ 100%
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