Bird communities inhabiting hot desert environments may be expected to be among the most vulnerable to rising temperatures, on account of the thermal stresses and unpredictable water and food resources encountered in these habitats. We can confidently predict that increasing temperatures in southern Africa’s hot deserts will cause range changes, but at present we have no capacity to predict which species will respond first or when the response will occur. Making such predictions requires a mechanistic understanding of the links between the physical/environmental characteristics of habitats and organismal performance. The physiological research that is needed to elucidate these links requires time-consuming and intensive study of individual species, making this approach generally unsuitable for anything more than a small subset of the species that make up arid-zone bird communities.

This aspect of the Hot Birds research project seeks to validate a behavioural index of vulnerability to heat stress in birds inhabiting hot desert environments. We are busy testing predictions that relate heat dissipation behaviours to underlying changes in body temperature and hydration status in model species that vary in terms of the relationship between environmental temperature and heat dissipation behaviours. The over-arching aim of this research is essentially to develop a rapid assessment tool, whereby the relative vulnerabilities of birds making up arid-zone communities to more frequent and severe heat waves can be assessed largely on the basis of behavioural observations. The development of such a rapid assessment tool will mean that the species most vulnerable to the impacts of climate change can be identified - in any desert environment, anywhere in the world – on the basis of readily collectable behavioural data.