For the last two years, from September to mid-February,Vleck and several graduate students have studied the parenting behavior of Adelie penguins at Palmer Station, a National Science Foundation base on Antarctica. Vleck, assistant professor of zoology and genetics, is studying the role testosterone, often associated with aggression, plays in parenting. Her research has shown that male penguins have high levels of testosterone before their mates lay eggs. After the eggs are laid, the testosterone level drops. Males probably can't afford to maintain a high level of testosterone and aggression when taking care of the chicks, she said.
Penguins form monogamous pairs and breed in dense colonies.
After the eggs are laid, the parents are tied to the nest for 55 to 60 days while they incubate the eggs and raise the chicks. The pair take turns guarding the nest. One parent may be nest-bound for weeks at a time while the other is feeding at sea. Penguins can't leave the nest unattended because of predators and freezing temperatures. She hopes to finish her research in another year.