Effect of variations in rate of growth on physiological parameters in the lizard Amphibolurus ornatus

Abstract

1. 1. At Bakers Hills, faster growing Amphibolurus ornatus lost weight when hypernatraemia following droughts caused increased urinary and evaporative water loss, and hence loss in body weight. 2. 2. No differences were found between faster and slower growing animals in preferred temperature, metabolic rate or electrolytes in the erythrocytes. 3. 3. At Canning Dam, even mild droughts caused severe hypernatraemia but, being slow growers, all animals maintained body weight. 4. 4. At Tuttanning, even severe droughts did not cause hypernatraemia, and so faster growers in the population did not lose body weight. 5. 5. None of the correlates of growth rate discovered could be used as a reliable marker for growth rate.