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 (PTT) devices to track Adélie and chinstrap penguins breeding on the South Orkney Islands during the pre-moult phase of the annual cycle. We show that Adélie penguins have an affinity to forage 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 aimed 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 with the overlap with potentially competing fisheries.