How do penguins organize themselves?
Finding a lone penguin is rare. There have been reports of individuals arriving at a beach several kilometers away from the place where they inhabit naturally, as happened with the penguin called “Happy Feet” found in New Zealand, but these are cases in which they are lost because of unnatural causes since they are extremely social birds.
All penguins usually nest in colonies and spend a significant part of their lives in them. They can swim and feed together, sometimes in smaller groups, but in the breeding season, the colonies become much crowded than normal. However, the colonies of the Fiordland Penguin (Eudyptes pachyrhynchus) and the yellow-eyed penguin (Megadyptes antipodes) are smaller than those of the other species and nests are separated by greater distances. In fact, this latter species is the least social of all penguins.
Usually, the members of the genus Spheniscus and the small blue penguins lay their eggs in rocky crevices or natural caves, which sometimes cause that the nests are not very close. Because of this, they can not interact in the same way as the Emperor penguins (Aptenodytes forsteri) or the Adelie penguins (Pygoscelis adeliae), which nest on the flat ground.
The colonies of the Gentoo penguins (Pygoscelis papua) also tend to be relatively small, since the number of members is frequently less than 1,000. The species that nest in large communities make impressive visual displays and have an extensive repertoire of vocalizations. The biggest colonies on record had 180,000 to 200,000 penguins. Imagine that!
The reason penguins live in colonies is just because they increase the chances of survival, both adults, and offspring. In the first place, among so many individuals, it is easier to find a partner to mate; second, it is also simpler to protect from predators because they can issue warning calls and defend the nests; and third, sometimes they can collaborate to find food. It is a question of cooperation.
In a colony, there is not a dominant male, as in other species of animals. Despite living in groups, within each colony penguins remain in pairs, sometimes alone or with their offspring. Penguins are usually monogamous birds, although there are exceptions. A monogamous couple ends in case one dies, they do not produce eggs together or for some other extraordinary reason.
Some species, mainly the large ones have only one offspring, but sometimes, individuals of the small species, such as Eudyptula minor and others, can have up to two at the same time. Both parents take turns caring their offspring, and when the chick has grown a little, they bring it to the “nurseries,” sites where other young penguins of the colony join. Penguins usually settle near the places where their parents raised them, and they return to the same spot each year to nest.
Social habits differ according to the species. For example, the Emperor penguins nest and feed together. Sexually mature adults regularly travel between the nesting area and feeding areas throughout the year, and when the weather is freezing, they huddle together to conserve heat. King penguins (Aptenodytes patagonica) tend to travel in groups of 5 to 20 individuals, but their nesting colonies contain thousands of them. While they are in the ocean, all penguins are less sociable than on land, because they focus on catching prey, swimming or doing other individual activities.
- Harris, Jose. The Penguin Social History of Britain: Private Lives, Public Spirit. Penguin UK, 1994.
- Müller-Schwarze, Dietland. The Behavior of Penguins: Adapted to Ice and Tropics. SUNY Press, 1984