Description: With a distinctive thin black stripe under their chin, the chinstrap penguin resembles the numerous Adelie penguins but is easily distinguished by their "chinstrap." These penguins also feed on krill. They are scientifically named Pygoscelis antarctica. Their chicks take about nine weeks before they are ready to go to sea. Chinstraps are more aggressive than the Adelies in their breeding behavior. The males occupy the rookeries first, the dominant males selecting the best breeding sites and driving away other, less aggressive birds. If the previous year's mate does not arrive within five days, the male will mate with another female. Should the previous year's female arrive late then there may be a fight between the females with the strongest female winning. Chinstrap nests resemble Adelie nests with the pebbles piled up by the couple. The female, in preparation for egg laying, makes a depression in the middle of the nest. This pebble nest serves to keep the eggs off the ground and allow melt water to run through. There is such a small window of time for breeding that the arriving penguins must build their nests immediately when they arrive, they can only use bare ground. If the snow melt is late then the areas for nest building are restricted.
