Introduction All animals must eat as subsequent assimilation of the ingested food provides the energy and building blocks required to sustain all life functions. The functional performance of the digestive system therefore has implications for all physiological processes, and the ability to procure food, subdue prey, and retrieve its energy provides the basis for locomotion, growth, and reproduction (Wang 2001). Energy status therefore dictates the expression of most behaviors and while the ectothermic nature of reptiles implies that the energy devoted to basal life functions, that is, standard metabolic rate (SMR), is smaller than within endothermic birds and mammals, an effective digestive system is nevertheless needed to survive the long-lasting periods between suitable prey encounter. Such fasting periods, which may last for months in some species, are attended with rather impressive changes in the structure and function of the gastrointestinal (GI) organs (Pennisi 2005). This phenotypic flexibility seems to reduce the maintenance costs of the GI organs during fasting but is obviously only a viable strategy as long as the animals retain the capacity to swiftly upregulate digestive functions immediately upon prey ingestion; otherwise, the prey would deteriorate or even rot within the gut of the predator.