10 fun facts about penguins

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When you think of penguins, the mind often associates them with the cold and icy South Pole. However, some species of penguins have managed to adapt even to environments that do not feature ice and snow, even colonizing tropical areas. In total, there are 18 species of penguins, 12 of which inhabit the cold lands of Antarctica, while the other six are found in various regions of the world, such as Oceania, South America, Africa, and the Galapagos Islands. Despite belonging to the same family, penguins are an extremely heterogeneous animal group, with ecological niches and behaviors vastly different from one another.

Penguins are aquatic birds closely tied to the marine world. Although they belong to the phylogenetic group of birds, during their evolution they have lost the ability to fly. To adapt to aquatic life, their bodies have undergone various transformations. For example, their wings have evolved into strong and waterproof fins, ideal for swimming with agility. Additionally, their skeletal system, which in birds is typically composed of hollow and light bones to aid flight, in penguins has developed denser and heavier bones. This adaptation allows them to dive easily into the water and reach considerable depths. Thanks also to webbed fins and a streamlined body shape, penguins are extraordinary swimmers, capable of moving with great efficiency and speed in their aquatic environment.

Despite the numerous morphological adaptations for living in aquatic environments and in particular conditions, penguins have retained their plumage, like all birds. However, their plumage is truly unique. Near the tail is the uropygial gland, present in some aquatic birds, which produces an oily substance capable of making the plumage waterproof. This oil covers the feathers, making them smooth and waterproof, allowing water to slide off without penetrating. This adaptation not only helps penguins stay dry while swimming but also aids their movement on ice, allowing them to slide easily on the surface. Additionally, the oil produced by the gland has anti-freeze properties, protecting the penguin from extreme cold and allowing it to survive temperatures that can drop to -60°C, as occurs in Antarctic regions.

The plumage of penguins is renewed through the physiological process of molting. During this period of about 20 days, penguins are forced to remain on land, as they lose the plumage that protects them from water and cold, which normally allows them to dive and hunt. Unable to feed at sea, they fast for the whole molting period, losing up to 50% of their body weight. This fasting state, however, is not limited to molting: penguins also fast during the breeding season, when they focus on caring for the eggs and chicks. Despite this, penguins are remarkably capable of storing fat reserves, allowing them to survive for long periods without food. A notable example is male emperor penguins, which can fast for up to 100 days during egg incubation.

Penguins are known for forming stable and monogamous bonds with a single partner, often lasting a lifetime. These pairs establish a relationship that includes shared parental care. Generally, penguins lay one to three eggs, but often the second and third eggs are considered reserve eggs in case the first egg is damaged. Unlike other birds, penguins do not build a nest, but both the male and female take turns incubating the egg, keeping it on their feet or under their abdomen to avoid direct contact with ice or ground, maintaining a stable temperature of around 30°C. Typically, the male initially takes care of the incubation while the female goes to feed at sea. When the egg hatches, roles are swapped, and the mother cares for the chick, providing nourishment and attention, while the father can return to the sea to replenish food after days of fasting.

Certain species of penguins, like the emperor and king penguins, live in very large colonies, ranging from 200 to 50,000 pairs. Within these colonies, recognition of their partner and communication among individuals occur through short and combined sounds, forming a sort of “primitive language”. Researchers have identified various tones and lengths of sounds in this communication system. Specifically, these two species of penguins possess a unique vocal system, characterized by two voices. The interference between two slightly different frequencies produces a distinctive rhythmical song that varies from one individual to another.

In the case of emperor and king penguins, some non-breeding pairs, or pairs that have lost their offspring, temporarily adopt chicks of other pairs. Even individuals left without partners can participate in this form of adoption. In the colonies of these species, there is often an imbalance in the number of males and females, with a greater presence of females. Consequently, some females remain without a partner. Breeding pairs that have suffered a reproductive failure, for instance, due to the loss of an egg or chick, continue to produce high levels of prolactin, the hormone that promotes maternal sensitivity and the inclination to care for offspring. This enables them to care for the chicks of other pairs, thereby playing an important role in communal caregiving within the colony.

Æptenodytes forsteri, the scientific name for the emperor penguin, is the world's largest penguin species and lives in one of the Earth's most extreme and inhospitable environments: Antarctica. At the South Pole, temperatures can drop to -60°C. To survive these extreme conditions, emperor penguins have developed numerous adaptations. Their body is protected by two layers of feathers and modified plumage, along with a significant fat reserve. The beak and wings are proportionally smaller compared to other penguins to reduce heat loss. The feet are covered with feathers, while the toes contain special fats that protect them from freezing. Additionally, to cope with freezing temperatures and strong winds, which can exceed 250 km/h, penguins gather in large groups, huddling close to each other to share body heat and protect one another.

Penguins are considered umbrella species, meaning species whose protection not only ensures their survival but also contributes to the preservation of entire ecosystems. Additionally, penguins play a crucial role as biological indicators, species that provide information about the health of an ecosystem and its changing conditions. In a period of increasing climate emergency that threatens the habitats of these animals, the protection and monitoring of penguins are becoming increasingly essential to understanding and preserving ecological balances.