The most difficult member of the genus to see in South America, the Adelie Penguin is decidedly Antarctic. Although it breeds on some sub-Antarctic islands, the bulk of the population breeds on various ice shelves and peninsulas on Antarctica. The species is highly pelagic and after breeding is very dispersive, with most adults moving north to rich feeding grounds and some occasionally reaching South America. This is by far the most studied species of penguin, and despite concerns of the negative impact of such intensive research, the population is stable or even growing. The Adelie is well known for its habitat of mounting icebergs to rest. Adelies also molt on ice floes, rather than in the breeding colonies, a strategy that is unique among penguins.