Honours projects 2014
1. Role of hydration state in thermoregulation: does a higher body temperature contribute to water savings in heat stressed birds?
Evaporative cooling is the most effective physiological pathway of heat loss in birds. However, evaporative cooling is expensive in terms of water requirements and is feasible only if a bird is adequately hydrated. Previous studies have proposed that birds will elevate their body temperature to promote heat dissipation through non-evaporative pathways. By reducing the demands for evaporative cooling this mechanism may contribute greatly to water savings in environments where water is scarce. This project will test the relationship between hydration state, evaporative water loss and body temperature regulation in heat-acclimated, arid-zone birds, e.g. Namaqua Doves (Oena capensis).
Despite many studies reporting heterothermy in endotherms (birds and mammals) very few of these explicitly test predictions on the adaptive value of heterothermy. By reducing body temperature when faced with low and/or unpredictable food availability, animals could reduce their energy demand and increase survival and fitness in unpredictable desert environments. This study will test the effect of different food supply regimes on the torpor patterns and body condition of the Karoo Round-Eared Elephant-Shrew (Macroscelides proboscideus).