When we see a bunch of penguins at an aquarium or zoo or even in a film, they generally look a lot alike to us.  But we might need to take a closer look, according to some recent research by a team of psychologists and animal behaviourists from two universities and a marine park.  They describe a fairly simple experiment in the prestigious scientific journal, Animal Behaviour, wherein they have concluded that African penguins, at least, use the unique assortment of black dots that adorn their chests as a means of telling one another apart.  African penguins live on the shores of southern Africa and are apparently very social with one another, making them ideal specimens to study.  A marine park in Italy has a captive population of the birds, and the workers there claim to recognize individual birds by those spot patterns on the birds’ chests.  That team of scientists devised a simple experiment to determine whether the penguins used the same technique to identify one another.  They built a small enclosure with plywood walls, just tall enough to prevent a penguin from seeing over.  They installed cameras on either end of the enclosure along with life-size pictures of two penguins pinned up on one far wall.  They then enticed a single penguin to enter the compound with one of the two pictures featuring their own mate and another of a stranger.  They next repeated the exercise putting up two pictures of its mate but one with the chest dots removed.  Finally, they put up two pictures, one of its male and the other of a stranger but both with their dots removed.  In the  first wo cases, the test penguin stared significantly more at the pictures of birds bearing its mate’s chest pattern but could not decide anything when the chest dots were removed from both pictures.  However, I cannot wonder what features are used by penguin species without any dot patterns on their chests.

David M. Bird, Ph.D., Emeritus Professor of Wildlife Biology, McGill University www.askprofessorbird.com