Feeding trips range from 5 to 72 hours in duration. Adelie penguins are capable of diving to depths of up to 175 m but usually feed within the upper 70 m of the water column. Adelie penguins breed between October and March on areas of rock in colonies of varying size. They start breeding at 3-5 years of age and live up to 20 years. They make nests out of small stones, lay two eggs, and raise up to two chicks per nest, depending on food availability.
Chicks are about two months old when they fledge.
The minimum breeding population has been estimated at approximately 7.5 million pairs in 1993. Although the chinstrap penguins forage at sea throughout the day and night, diving effort is concentrated near midnight and noon. They feed mainly on krill and fish and are considered near-shore feeders, feeding close to their breeding colonies. They catch prey by pursuit-diving using they flippers to fly through the water. Chinstrap penguins on land often toboggan by propelling themselves by their feet without the use of their flippers.