While penguins are widely recognized for their distinctive waddle and sleek appearance, the unique odors associated with them are less commonly discussed.
The Distinctive Penguin Scent
Visiting a large penguin colony often presents a powerful and memorable olfactory experience. The air can carry a strong, pungent, and distinctly fishy aroma, frequently described as ammonia-like. This collective scent is a combination of various elements present in their crowded nesting grounds. While overwhelming to human senses, it forms a natural part of the penguin’s environment, varying slightly by species or location yet maintaining a core “penguin” smell.
Why Penguins Smell That Way
The distinctive odor of a penguin colony arises from several biological and environmental factors. A primary contributor is their fish-heavy diet, which naturally leads to fishy-smelling excrement. For species that consume large amounts of krill, their droppings can even take on a pinkish hue.
Guano, the accumulated droppings of penguins, is a significant source of the strong smell. Large colonies produce vast quantities of guano, which contains uric acid and other compounds that release potent, ammonia-like odors as they decompose. This accumulation can be so extensive that penguin colonies have been located from satellite images due to the visible trails of their droppings. The guano also carries the scent of their diet, including “crushed-up krill sort of scents.”
Penguins also possess a uropygial gland, or preen gland, located at the base of their tail. This gland secretes an oil that penguins spread over their feathers to maintain waterproofing and plumage. While its main purpose is protective, this preen oil can carry a faint, distinct scent. The chemical composition of this oil can vary among individual birds based on factors such as age, sex, reproductive status, and diet, contributing to their overall body odor. The sheer density of penguins in their breeding colonies concentrates these various smells, making them more noticeable and pervasive to human visitors.
How Penguins Use Scent
While the strong odors of penguin colonies are evident to humans, penguins themselves possess a developed sense of smell and utilize it for various purposes. Research indicates that penguins can use scent for individual recognition within their crowded colonies. Studies on Humboldt penguins, for example, show they can discriminate between familiar and unfamiliar individuals, and even between kin and non-kin using olfactory cues, which helps prevent inbreeding. The preen oil is believed to be a source of these personalized scents used in recognition.
Scent also plays a role in navigation and homing for some penguin species. King penguins may use volatile organic compounds (VOCs) from their feathers to help locate their colony from a distance and orient themselves within its confines. This olfactory navigation aids them in returning to their specific nesting sites, especially in dense and visually complex environments.
Some penguin species employ their sense of smell for foraging. African and Humboldt penguins can detect dimethyl sulfide (DMS), a sulfur compound released when krill consume phytoplankton. This allows them to locate productive foraging areas in the ocean, even though they are primarily visual hunters. Interestingly, krill themselves react to the scent of penguin guano, altering their swimming and feeding behaviors in response to the presence of a predator’s droppings.