Finding a friend in a crowd is hard enough but try putting a name to a face when there are 20,000 penguins to choose from.

Technology capable of doing just that, however, is now making life a little easier for researchers studying the lives of jackass penguins in Robben Island, South Africa.

The penguin’s name is likely to be a number, and it is the chest rather than the face that is recognised, but the software is an invaluable tool. The technology enables researchers to track the individual movements of virtually all the birds in the colony and to pick out a single one from among thousands.

The penguins may all look the same to the human eye but the recognition system records and distinguishs between the pattern of spots on their chests and stomachs.

It has a huge advantage over tags in that it can operate without a single bird having to be caught, which greatly reduces stress on penguin and scientist. “These penguins are vicious, nasty things that bite and scratch. They have very sharp beaks. I do love them but, by God, they can hurt,” Professor Barham said. “It’s no fun trying to get tags on them.”

African penguins, Spheniscus demersus, popularly known as jackass because their call sounds like a donkey’s braying, are undergoing a steep decline and researchers hope that the software will help them to find ways of improving the birds’ prospects.

A camera set up on a penguin track in Robben Island, near the prison where Nelson Mandela was held, records and analyses the pattern of spots of each bird that walks past.

White feathers cover most of their fronts but dotted about in a random pattern are small spots, each formed by three or four black feathers. The most common number of spots is 12 but there can be as few as 2 and as many as 20.

Penguins walk past the camera as they set out for the sea to feed and on their return. In one day the system is able to record 20 per cent of the birds and after a month 98 per cent of the 20,000 penguins on the island have been identified individually. Once the researchers know which penguin is which they are able to learn more about how the animals live.

Peter Barham, Professor of Physics at Bristol University and a self-confessed penguin fanatic, said the system would help to provide basic data such as the average lifespan of a penguin. He is confident of getting more detailed insights into how the African penguins live, such as how frequently they feed, how long they stay at sea and how they are affected by climate and fish stocks.

More than a million African penguins were found on the southern African coastline in the 1930s but the numbers slumped because so many eggs were taken and the guano, which they burrowed into to nest, was removed. In the past seven years they have suffered a further decline, which researchers fear has been caused by climate change. The birds depend on sardines and anchovies in the Agulhas current, which scientists think may have been pushed out to sea beyond the penguins’ reach.

The penguin recognition system, backed by Earthwatch and the Leverhulme Trust, is expected to be able to be used for a wide variety of animal monitoring schemes, including butterflies and whales, and will be on show at this year’s Royal Society Summer Science exhibition in London from June 30 to July 3.

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