An 40Ar/39Ar chronology of in-situ to near insitu volcanic ashfall deposits indicates that the surficial stratigraphy of Arena Valley extends back at least to middleMiocene time. Wet-based glacial ice occupied part of Arena Valley more than 11.3 Ma ago. Thick, northeast-flowing ice subsequently engulfed Arena Valley, again more than 11.3 Ma ago. Only minor glacier expansion occurred during Plio...

For seabird species, the presence of conspecifics in a crowded breeding colony can obstruct locally available orientation cues. Thus, navigation to specific locations can present a challenging problem. We investigated short-range orientation in King Penguin (Aptenodytes patagonicus) chicks that live in a large and densely populated colony. The two main objectives were to determine whether chick...