Habitat preferences of Adélie Pygoscelis adeliae and Chinstrap Penguins Pygoscelis antarctica during pre-moult in the Weddell Sea (Southern Ocean)

In order to understand and mitigate for the potential impacts of anthropogenic disturbance on marine predators, it is fundamental to gain insight into the drivers behind the temporal variation in their current distribution. With this in mind, we used platform terminal transmitter devices to track Adélie Pygoscelis adeliae and Chinstrap Penguins Pygoscelis antarctica breeding on the South Orkney Islands during the pre-moult phase of their annual cycles. We show that Adélie Penguins have an affinity to forage near and moult on sea-ice, and that Chinstraps remain over the shallower shelf waters during pre-moult, and return to the colony to moult. However, habitat models developed to predict the preferred foraging habitats of penguins during pre-moult had low predictive power. This indicates that predictive models may be insufficient to understand the distribution and foraging behaviour of penguins during certain stages of the life-cycle, and that collecting empirical data from individual colonies or archipelagos is vital if we are to understand the potential implications of future climate warming, or indeed the overlap with potentially competing fisheries.