Research in this programme is currently focused on two areas:
1) Hot bats - Climate Change and Small Mammals in Hot Habitats
Predictions of the impacts of climate change on terrestrial vertebrates have largely relied on pattern-based, climate-envelope modeling approaches. Such models provide insights into how organisms exposure to environmental conditions will change in future, but do not usually incorporate information on the physiological processes that determine their sensitivity to warmer thermal environments. We are currently developing mechanistic models to predict climate change impacts on the basis of physiological processes. Bats living in hot environments provide an ideal opportunity to develop mechanistic models of climate change impacts, because a) we know that elevated maximum temperatures have already caused episodes of direct mortality, and b) the energy and water requirements of small endotherms exposed to high environmental temperatures are relatively straightforward to model. Work in this area in the last few years has focused on interspecific variation in heat tolerance among bat communities inhabiting hot environments, and quantifying the relative importance of cutaneous versus respiratory evaporative heat dissipation for thermoregulation during hot weather.
2) Ecology and Evolution of Mammalian Heterothermy
Heterothermic responses such as torpor and hibernation are widespread in small mammals, and recent decades have seen a dramatic increase in the number of species from tropical and subtropical latitudes known to use heterothermy. The broad aim of this project is to test hypotheses regarding the optimal expression of heterothermy, and thereby to identify ecological and evolutionary correlates of heterothermy in mammals. Recent work has included an investigation of the influence of solar radiation on rewarming from torpor in eastern rock elephant shrews. Data from this study reveal that, during rewarming from torpor, solar radiation is used to supplement rather than replace endogenous metabolic heat production.