Sunday, July 20, 2014

King Penguin Chicks Use Collective Decision Making to Find Home Spot

king penguin chicks

King penguin chicks form groups to navigate to their home spot and they need to make collective decisions as they move along their way. As with humans or any animal, when behaving in a group, decisions have to be made. Some will be leaders, some followers. Sometimes there will be cooperation and sometimes conflict. A recent study, published in the journal Animal Behavior, provided some empirical data on how well king penguin chicks work in pairs to navigate. The study was carried out by scientists from the University of Oxford in the United Kingdom, the University of Amsterdam in The Netherlands and CFE-CNRS Montpellier in France.

King penguins live in Antarctica and an entire colony of adult king penguins may consist of a half a million breeding pairs. The colony moves in groups of different sizes on land and in the water. After eggs are hatched and chicks are born, the parents at first split up and one parent makes a very long trip (up to 400 km, which is about 250 miles) traveling to the sea in winter for food. An interesting thing to note is that when the parents return from their long trip, they can identify their own chick’s voice among the crowd, even though the crowd may consist of about 500,000 penguins. When the chicks are a bit older, then both parents leave to get food and the younger chicks are left in the care of other juveniles.

The chicks form crèches, which are chick groups, to keep warm and avoid predators, and each crèche has a specific location. Being able to navigate to the location of the crèche is crucial for a chick’s survival. When parents eventually return with food, they need to return to the locality of the home crèche to feed their young. If the chicks are not in the right place, they will not get food.

The chicks must move together to get to their home spot. The researchers in the study aimed to determine how king penguin chicks make collective decisions about which direction to move in to find the crèche. They considered the trade-off between group cohesion and individual preferences. The aim of the study was to collect empirical data on conflict resolution during navigation.

In the study, they chose to look at pairs of chicks. The scientists manipulated the levels of conflict by pairing individuals from either the same crèche (no conflict) or different crèches (conflict over desired destination). They then observed the “homing” behavior of both types of pairs. 15 pairs of same- crèche chicks and 16 pairs of different crèche chicks were studied. Each chick had a GPS system attached to their body.

The results showed whether the chicks were better at navigating to their crèche in pairs or when moving alone. The results also determined whether conflict over the desired destination changed the navigation and how the chicks resolve conflicts. Chicks from the same crèche were more precise in getting to their home crèche. Each of the king penguin chicks in a pair took turns being the leader and following. Chicks that were from different crèches were more likely to split up the pair than those pairs that were from the same crèche. The results showed that king penguin chicks use collective decision making when traveling long distances to get to their home spot.

The Scientist
BBC Nature
final source

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