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

Blood samples were taken throughout the year from captive gentoo Pygoscelis papua (n = 5) and rockhopper Eudyptes crestatus (n = 10) penguins to measure seasonal variations in retinol and alpha-tocopherol levels. Retinol levels ranged from .58 mug/ml to 1.09 mug/ml and alpha-tocopherol 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. Changes 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 the vitamin A and E intake was calculated. Blood vitamin levels of penguins on a supplemented diet were similar to those in the wild. (C) 1993 Wiley-Liss. Inc.