The information perceived through the five senses is key to defining the environment that each animal conceives as its habitat. The multiple variables of this ability were studied in detail in humans, but not so much in other living beings.
a study published in the scientific journal Annals of the New York Academy of Sciencesfrom the University of Turin, in collaboration with the Jean-Monnet University of Saint-Etienne and Zoomarinethe zoo located on the outskirts of Roma, sets a precedent with its research on African penguins.
The new research on this particular species of penguins reveals that they have the ability to associate certain sounds with the size of the objects in front of them.
The brain associates, the mind interprets
Among its complex functions, the brain is the organ that is responsible for combining the signals sent through sight, touch, hearing, taste and smell to compose a coherent representation of the world.
However, in some cases decoding is not limited to integrating already known information, but also establishes systematic relationships between characteristics perceived by different senses, which then become patterns and help us recognize environments.
This is what neuroscience calls «crossmodal correspondences» o cross-modals. It refers to systematic links that the brain draws between characteristics perceived by different senses.
One of the capacities that was widely studied is to establish the relationship between the frequency of sounds and the size of objectsinvestigated in humans and rarely documented in other living beings.
There is documentation in different vertebrates, but experimental evidence in birds is scarce. Therefore, the recent discovery in penguins Africans amaze the scientific community and can help understand how they perceive and orient themselves in complex environments, both on land and underwater.
The African penguin, also known as the «Cape Penguin» or «jackass penguin«, whose scientific name is Spheniscus drownedbelongs to an ancient evolutionary group of birds and its vocalizations convey biologically relevant informationsuch as the age and body size of each individual.
It is a species endemic to the coasts and islands of southern Africa, specifically Namibia and South Africa. It measures between 60 and 70 centimeters in height and weighs between 2.7 kilograms and 4 kilograms.
Its plumage, as seen in the photos, is black on the back and white on the chest and belly, but it has a distinctive black band in the shape of an inverted «U» and a single thin black band on the chest. This differentiates it from other species of the genus. Spheniscus and it is the visual characteristic that distinguishes them.
An interdisciplinary team of researchers analyzed how the colony of African penguins housed in Zoomarine reacted to sound and visual stimuli presented in a controlled manner.
They discovered that these seabirds They are able to associate the pitch of a sound with the size of an objectlinking low sounds with larger objects and high sounds with smaller objects.
During the test, each specimen was placed in front of two black cubes that it had never seen before, one large and one small. As I watched this scene, a single sound, low or high, was played.
The objective was to determine if the animal spontaneously linked the frequency of sound with size of object. In 80% of the cases, the penguins headed towards the large cube after hearing a low sound and towards the small cube after hearing a high sound.
The same trend was also observed when analyzing the direction of the gaze of animals, which reinforces the interpretation that these were not random elections.
Having the possibility of learning this relationship can represent an advantage in complex social contexts, such as penguin coloniessince it facilitates the couple recognitionhatchlings and other individuals, even when visibility is limited, whether due to waves or fog.
The systematic association of low sounds with large objects and high sounds with small objects is considered a sensory trait that increases their survival.
Researchers believe it could derive from regularities present in the natural world that penguins associated from their daily experiences in nature, where larger animals and objects tend to produce lower-pitched sounds and smaller ones tend to emit higher-pitched sounds.
The data collected constitutes the first experimental evidence that African penguins can integrate auditory and visual information to generalize a systematic relationship between pitch and size across different sensory dimensions.
With information from the ANSA agency.
