Ad�lie penguin parental activities and reproduction: effects of device size and timing of its attachment during chick rearing period

Abstract

Effects of device attachment on parental activities and body mass change in instrumented birds and their mates, and on chick growth and survival, were studied in Adelie Penguins Pygoscelis adeliae in Lutzow-Holm Bay, Antarclica. Penguins on which small devices were fitted with rubber band harnesses exhibited increased foraging trip duration, and decreased body mass, food delivery rate, chick growth and chick survival. Their mates did not increase food delivery rate. Those on which small or large devices were fitted with epoxy glue did not change foraging trip duration, body mass, or chick survival. However, large devices decreased chick growth. These effects were more obvious; among penguins fitted with devices later in the chick rearing period, and suggest that: 1) parents fitted with devices give a priority to maintenance of their own energy reserve over guarding and food delivery for chicks; and, 2) parents' decreasing energy reserves later in the breeding season might intensify the effects of devices.