Biparental Care of Chinstrap Penguin: Molecular Sexing and Life History in the South Shetland Islands, Antarctica

Chinstrap penguin, Pygoscelis antarctica, breeding biology involves several distinct stages of chick rearing, in which each parent varies in their relative contribution to reproductive success. We investigated tertiary adult sex ratios using molecular sexing in breeding colonies during guard and crèche stages of chick rearing at Admiralty Bay (King George Island) and on Stinker Point (Elephant Island) in the 2010/2011 breeding season. We analyzed 52 blood samples and found this represented 31 males and 21 females. We observed that the adult sex ratio in guard and crèche stages did not vary signi cantly. However, we feel evidence did infer di erences in relative biparental care behavior between the two stages studied. us, it was possible to develop a potential hypothesis of relationship between sex ratio of adults present during di erent stages of the breeding season by molecular biology technique with Chinstrap penguin life history and gain understanding of the importance of contributions of both sexes in raising their o spring and for attaining reproductive success.