The influence of environmental temperature on learning and memory in juvenile tuatara (Sphenodon punctatus): Will a warming climate produce smarter reptiles? (#153)
Phenotypic plasticity in response to environmental change can be highly adaptive and increase fitness in variable environments. The plasticity of a wide variety of morphological and physiological traits have been studied across all types of organisms. However, learning ability has received comparatively little attention, whilst ecologically relevant and vital to numerous behaviours. Incubation temperature has been found to influence learning ability in lizards with warmer temperatures producing hatchlings with enhanced learning ability, but the plasticity of learning in response to ambient temperature during learning has not been established. With global air temperatures predicted to rise up to 4.8oC by the 2100s, exposure to warmer environments could be beneficial to some reptile species through enhanced learning ability.
The tuatara is a New Zealand endemic reptile and the last remaining representative of the order Rhynchocephalia. Their cold-adapted lifestyle puts them at risk of rising temperatures, so understanding their response to a warmer climate is necessary for conservation management. If the learning ability and hence behavioural flexibility of this unique species is enhanced by warmer climates, this could improve their ability to cope with novel situations and increase their chance of survival. Experiments are underway to assess the effect of ambient temperature on performance in a spatial learning task requiring tuatara to learn the location of an accessible positive reinforcer in a y-maze. If warmer temperatures enhance learning ability, this study will mark the first instance in which temperature has been shown to affect tuatara cognitive ability, suggesting there is potential for cognitive adaptation in this species as global temperatures rise. Conversely, if cooler temperatures are more conducive to learning then tuatara may not have the behavioural flexibility required to respond successfully to novel environments generated by climate change. The outcomes of this experiment will contribute to guidelines informing tuatara conservation and test for shifts in reptilian cognitive ability in a wamer environment.
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