Resolution of navigational conflict in king penguin chicks

Conflicts may arise within a moving animal group if its members have different preferred destinations. Many theoretical models suggest that in maintaining group cohesion conflicting preferences can have an overwhelming influence on decision making. However, empirical studies, especially on wild animals, remain limited. Here, we introduce a new study system for investigating collective decision making: king penguins, Aptenodytes patagonicus. Their gregarious lifestyle, the colony's organization into subgroups and group travel make king penguins especially interesting for studying collective movements. Chicks spend their first year of life in groups with other chicks (crèches), and if displaced will return to their crèche. We examined how different levels of navigational conflict affect such homing, by comparing the performance of pairs of chicks from the same crèche with pairs from different crèches. The majority of chicks in both treatments travelled at least part of the journey together; when doing so they were more efficient and faster than individuals travelling alone. Chicks took turns in leading and following. Chicks with a common destination (same-crèche pairs) were more precise at homing and less likely to split up than those with a conflict over preferred destinations (different-crèche pairs). Our results support some, but not all, predictions derived from theoretical models.