Professor Timothy Clutton-Brock: "Guards alert the others"

Standing guard just gives it more time to save its own skin.

The discovery could lead to a better understanding of how humans succeeded in learning to look after one another.

Mutual benefit

Why some creatures risk their lives for the benefit of others is a puzzle for scientists, because it contradicts an animal's instinct for survival.

Feeding meerkats are vulnerable to attack

Meerkats are often seen doing guard duty while others in their group forage for beetles and larvae in the dusty earth. Scientists thought the guards did this because they benefited from a lookout when they themselves came to feed.

But research in South Africa has shown this is not true.

If the meerkats' behaviour was truly altruistic, the scientists reasoned, then:

• Guards should be more likely to be killed
• There would be a rota of guard duty among the animals
• Meerkats living alone would not do guard duty

However, the scientists from the UK and South Africa saw that none of these things actually happened, after watching 18 different groups of meerkats in the Kalahari Gemsbok Park, SA.

London's police used meerkat images in their neighbourhood watch scheme

Not one meerkat guard was attacked by a predator in 2,000 hours of observation.

They did sound an alarm upon spotting an eagle or jackal, but they were also the first to dash into a nearby burrow. Standing guard gives a meerkat extra time for saving its own skin.

The team also saw that the animals would only stand guard when they were not hungry and when no other meerkat was already on watch. There was no fixed rota of duty.

Human kindness

Professor Timothy Clutton-Brock, from Cambridge University, led the research and says it may explain some aspects of human behaviour too.

"It may provide a potential explanation for the evolution of co-operation behaviour between unrelated individuals and of course the animal which has the most elaborate forms of co-operation is man," he says.

"So possibly this general approach to animal behaviour will in the very long run provide some additional links between the evolution of human co-operation and the distribution of co-operation in animals."

The research is published in the journal Science.