Book Review - Fraser's Penguins - By Fen Montaigne - NYTimes.com

Bill Fraser has been closely observing and recording the habits of birds near Palmer Station for 35 years. Such depth of experience allowed him to notice some troubling changes. Adélie penguin colonies, and the brown skuas that depend on them for sustenance, were rapidly declining; chinstrap penguins were moving in; and the population of fur seals and leopard seals was on the rise. What was going on?

Laboriously pondering factors biological and meteorological, Fraser eventually linked local Adélie declines with the cascade effects of warmer winter air and sea temperatures along the peninsula. Higher temperatures bring more snow, which delays the start of mating and nesting season, which results in smaller penguin chicks and a higher mortality rate. Warmer seas reduce the extent of sea ice, which krill (penguin food) depend on and Adélies rest upon before launching foraging trips into the Southern Ocean.