Influence of feeding on the metabolic rate of the lizard, Eulamprus tympanum

We measured the increase in metabolic rate following feeding, or the specific dynamic action (SDA) of feeding, in the lizard Eulamprus tympanum that feeds opportunistically and frequently. The SDA of most reptiles studied to date is pronounced in relation to other vertebrates, but most species for which data are available consume large meals infrequently. We chose to measure SDA in E, tympanum because it is typical of most lizards in that it feeds frequently. The SDA pattern of E. tympanum is typical of other animals, where metabolic rate increases to a peak following feeding then gradually decreases to prefeeding values. Metabolic rate in E, tympanum increases by up to 2.4 times the prefeeding values and remains elevated far up to 48 h. The SDA effect is much less in a lizard that feeds opportunistically and frequently than in sit-and-wait foraging reptiles. The duration of the SDA is greater in E. tympanum than in many other vertebrates and may be related to an ectothermic lifestyle, meal size, or diet composition. On the basis of diet and feeding strategy E. tympanum is probably typical of lizards that feed frequently, but there are too few data to make detailed comparisons.