The Right Way Home
(February 22nd, 2016) Although not at home on our shores, the European FP7-funded PENGUINAV project was initiated in 2011 to discover how groups of penguins coordinate their travels. Now, more and more results shed light on the matter.
On the remote Islands of Kerguelen, in the southern Indian Ocean and 3,300 km away from the nearest human population, lives the king penguin (Aptenodytes patagonicus), Chicko, with his big family. Once conceived, little Chicko developed in his egg for about 55 days but, unlike other penguin species that make a nest, Chicko’s egg was carried carefully on his parents' feet. After hatching, Chicko grew stronger for another 40 days or so, also sitting on the feet of his mummy or daddy. During the next four months, Chicko reached 12 kg and 90 cm in height. In the months to come, while mum and dad forage at sea, our big “woolly” boy spent all his time together with his peers - to brave the winter and predators, king penguin chicks form groups called crèches. As he grew older, he became more inquisitive. Now, at 12 months, Chicko has the courage to walk along the beach on his own. Suddenly, he notices some strange moving figures in the distance. Cautiously, he draws nearer and eyeballs the intruders. Feeling they don’t want to do him any harm, he walks on.
The strange creatures Chicko met was a friendly team of explorers, who themselves braved the Antarctic winter to understand penguin navigation. The PENGUINAV study, led by Anna Nesterova, University Oxford, brought together scientists from all over Europe: the CEFE-CNRS in France, the Alfred Wegener Institut and Max Planck Institute for Ornithology in Germany, the University of Amsterdam in The Netherlands and Eötvös University in Hungary. Funded by the Marie Sklodowska-Curie Actions and the Institut Polaire Français Paul-Emile Victor, the project’s main goal, according to Nesterova, was to determine “how animals make decisions in groups and coordinate their movements when travelling together. This question has recently emerged as a hotly debated topic in behavioural science. Yet in spite of a strong theoretical framework, empirical studies of group decision-making remain limited. Thus, one of the main aims of the PENGUINAV project was to provide much needed experimental work on animals navigating in their natural environment.”
The long and exciting expedition to the cold south provided the scientists with a lot of data, which is still being analysed. In one of the first published studies that came out of the project, the researchers separated a few chicks from their crèche, attached a mini-GPS logger and followed the chicks on their way back to the colony. “Some pairs of chicks were displaced from the same crèche. The other set of pairs consisted of chicks that were taken from two different crèches. Chicks that came from the same crèche liked to walk home together. However, chicks that came from two different locations in the colony split up along the way and walked home independently. It was more important for them to get to the right place in the colony than walking with a partner,” shares Nesterova.
For another paper, scientists again looked at the navigation of chick pairs from the same crèche. This time, however, some of the pairs consisted of both an experienced penguin chick that knew the path to the crèche very well and a naïve chick that hasn’t been displaced before – other pairs were made up of two naïve chicks. Unsurprisingly, the scientists found that experienced chicks navigate better than naïve chicks and that naïve chicks can improve their navigation, if they stick to their experienced partner. In addition, Nesterova and colleagues observed that chicks from naïve pairs took turns in leading and following, while chicks from mixed pairs were mostly led by the experienced chick.
“This has been the first study that investigated group navigation in king penguins, thereby broadening our knowledge of king penguin biology and providing valuable empirical tests for theoretical models of leadership and information transfer within animal groups,” concludes Nesterova.
As for Chicko, in a few years, when he is old enough, he will mate with a penguin lady. And their offspring will, most likely, inquisitively question the next team of friendly, scientist explorers.
Photo: www.publicdomainpictures.net/Petr Kratochvil (three penguins), Anna Nesterova (chick with camera)