ANNUAL VARIATIONS IN PLASMA RETINOL AND ALPHA-TOCOPHEROL LEVELS IN GENTOO AND ROCKHOPPER PENGUINS

Blood samples were taken throughout the year from captive gentoo Pygos celis papua (n = 5) and rockhopper Eudyptes crestatus (n = 10) penguin s to measure seasonal variations in retinol and alpha-tocopherol level s. Retinol levels ranged from .58 mug/ml to 1.09 mug/ml and alpha-toco pherol levels from 30.8 mug/ml to 50.7 mug/ml for the gentoo penguins. The rockhopper penguins' retinol levels ranged from .63 mug/ml to 1. 14 mug/ml and alpha-tocopherol from 22.3 mug/ml to 40.8 mug/ml. Change s in body mass were used as an indicator of the start and duration of feather moult. Food consumption was recorded daily for the year, and t he vitamin A and E intake was calculated. Blood vitamin levels of peng uins on a supplemented diet were similar to those in the wild. (C) 199 3 Wiley-Liss. Inc.