Panting thresholds of lizards. IV. The effect of dehydration on the panting threshold of Amphibolurus barbatus and Amphibolurus muricatus.

Amphibolurus barbatus which occupies arid and mesic habitats elevates its panting threshold with increasing loss of body water, thereby minimizing water loss at the expense of thermoregulatory effectiveness. Change in panting threshold is greatest up to losses of body water of 6-8% of hydrated weight, after which adjustment of the threshold is of lesser magnitude. Amphibolurus muricatus, a species restricted to the more mesic regions of Australia, does not show any change of panting threshold with progressive dehydration.