Abstract:
Mammals in drylands are facing not only increasing heat loads but also
reduced water and food availability as a result of climate change.
Insufficient water results in suppression of evaporative cooling and
therefore increases in body core temperature on hot days, while lack of
food reduces the capacity to maintain body core temperature on cold
nights. Both food and water shortage will narrow the prescriptive zone,
the ambient temperature range over which body core temperature
is held relatively constant, which will lead to increased risk of
physiological malfunction and death. Behavioural modifications, such
as shifting activity between night and day or seeking thermally buffered
microclimates, may allow individuals to remain within the prescriptive
zone, but can incur costs, such as reduced foraging or increased
competition or predation, with consequences for fitness. Body size will
play a major role in predicting response patterns, but identifying all the
factors that will contribute to how well dryland mammals facing water
and food shortagewill copewith increasing heat loads requires a better
understanding of the sensitivities and responses ofmammals exposed
to the direct and indirect effects of climate change.
