Vitamin E does not elevate survival in free-ranging lizards
Free radical theory predicts that the unavoidable production of reactive molecules as a by-product of the respiratory transport chain will pathologically affect organismal function and fitness and lead to disease and a shortened life span. This suggests that free radical production may be linked to metabolic rate, which in turn relates to foraging strategies and intrinsic growth rate and could therefore be important for directing the evolution of life histories. We designed an experiment in which young lizards (Australian Painted Dragons, Ctenophorus pictus) received an implant with a- Tocophorol (Vitamin E) or control vehicle (cocoa butter). They were released into the wild and monitored for survival. Recapture rate was eight per cent for vitamin E-treated lizards and 16 per cent for controls, resulting in no significant difference in probability of being recaptured. We discuss the importance of dose-dependence and context-dependent effects of this supplementation and outline other physiological factors that may be driving mortality rates in young lizards. 2009 by the American Society of Ichthyologists and Herpetologists.