Tradition explains why some meerkats are late risers

(PhysOrg.com) -- Just as afternoon tea is traditional in England but not in France, different groups of meerkats have different ways of doing things, Cambridge zoologists have found.

After studying meerkats in the Kalahari for the past 10 years, Dr Alex Thornton and colleagues from the Department of Zoology found that some groups of meerkats always got up later out of their sleeping burrows than their neighbours.

These differences appear to have been maintained as local traditions, with patterns of behaviour in different groups being spread by learning from others.

Studying social traditions among animals in the wild is difficult because it is hard to prove that differences in behaviour are due to the social spread of information rather than genetics or environmental factors.

This is the first time such traditional patterns of daily activity have been observed in animals outside the laboratory, and the study is published this week in Proceedings of the Royal Society B.

According to lead author Dr Thornton: "Studies of animal traditions are essential for understanding the biological origins of human culture."

"Because most previous studies examined groups of animals separated by large distances it has been extremely difficult to work out whether behavioural differences between groups really are traditions, or whether they might be better explained by genetic differences or differences in the local ecology."

Dr Thornton's study site in the Kalahari Desert is shared by fifteen meerkat groups with overlapping territories, and group differences in getting-up time could not be explained by differences in ecological conditions.

And as male meerkats always breed outside the group that they were born into, genes get shuffled between groups, so genetic factors are unlikely to account for group differences.

"We found that new immigrants adopted the behaviour of their new groups and that differences between groups were maintained despite groups changing in size and structure as old members died and new ones were born," says Dr Thornton.

"So it seems that, like afternoon tea or an apéritif before dinner, meerkat getting-up times are local traditions passed down through the generations."