UNLIKE the rat and the rabbit, it seems from nutritional studies made by several groups of workers that the chicken needs little vitamin E, providing its diet contains an adequate supply of selenium and only limited amounts of unsaturated fat1–3. Since tissue-levels of ubiquinone in the rat4 and rabbit5 are high compared with those given for some other animal species6 and since these levels have been found to be dependent on vitamin E4,5, it was of some interest to investigate tocopherol- and ubiquinone-levels in the chicken and some other avian species, with particular reference to those which show considerable differences in their basal metabolic rates. Chickens were reared to 7 weeks on an ordinary commercial ration, and a group of 4 pigeons and 12 canaries were purchased as adult birds from a commercial supplier. Selected tissues from each species were examined for ubiquinone, ubichromenol and α-tocopherol by analytical methods described previously7.