Penguins use smell

The mystery of how penguins find their relatives in vast colonies may have been solved after scientists suggested they use their smell to locate their family.

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Penguins could also use their sense of smell when searching for a mate to determine whether or not they are related to the bird in question, according to a new study.

The findings suggest birds may have a much better developed sense of smell than previously thought, and could help experts design programmes to preserve endangered species.

Penguins form monogamous pairs and share the responsibility of rearing their young while taking turns to leave the nest to gather food.

Even after travelling for several days in search of prey, the birds are inevitably able to find each other when they return to the colony.

Previous studies have shown that sea birds use smell to guide them home and to forage for food but the new research, published in the PLoS ONE journal, is the first to suggest that the sense might also help them recognise members of their family.

Researchers based at Brookfield Zoo near Chicago, USA, studied a group of dozen endangered Humboldt penguins which included breeding partners, their offspring and others which were not related.

They took samples of a pungent oil used in preening from each penguin and rubbed it inside a series of dog kennels before allowing the birds to explore them.

The researchers found that penguins were able to tell the difference between the smells of familiar and unfamiliar birds, and spent more time in kennels containing scents they recognised.

Jason Watters, one of the researchers from the Chicago Zoological Society, said: It's important for birds that live in large groups in the wild, like penguins, to know who their neighbours are so that they can find their nesting areas and also, through experience, know how to get along with the birds nearby.

Being able to recognise family members is also useful in the colony because it prevents siblings from becoming mates, which could lead to unhealthy offspring.

When given the choice of kennels containing unfamiliar relatives and non-relatives the penguins were more attracted by the birds which were not family members.

Suggesting they were able to detect the smell of their kin and were more curious about potential new partners

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The discovery could help zoos manage breeding programmes, researchers said.

Nick Collins