Squirrels are connected by three degrees of separation

London, March 19 : Social networking - the phenomenon behind sites such as Facebook and MySpace - is not is not just limited to humans, for squirrels also exhibit it.

A leading scientist at Auburn University in Alabama has developed a Facebook network of squirrels, by watching everything from kissing, sniffing, playing or grooming in 65 Columbian ground squirrels.

Theodore Manno, from the department of biological sciences at the University, spent three weeks in 4-metre-high observation towers keeping a watch on the squirrels, including Lava Lamp and Mercedes.

Thereafter, he logged the interactions between the squirrels and was able to put together a plan of the rodents' social network.

Manno described "friendly interactions" in squirrels as instances when they kissed, sniffed, played or groomed each other.

He then created a computer model of the network and tried to find persistent companionships, i.e. pairs of squirrels that interacted more often than would be expected from just random associations.

Manno discovered that the whole colony of 65 ground squirrels was connected, approximately, by three degrees of separation, indicating that any two squirrels could be connected by three intermediate animals.

He also found that popular individuals of the same age and reproductive status were more likely network with each other, thus deserting a few loners on the margins of the colony. He found that among the 65, six squirrels were not sexually mature, and all six were on the sidelines of the network.

Manno then reproduced a situation where the animals are hunted by humans, and removed squirrels from his computer model.

He found that random removals had little effect, but the targeted removal of more connected squirrels tended to disintegrate the network into disjointed groups when he removed more than seven individuals.

He concluded that some squirrels seem to play key roles in keeping the communities together and that removing these individuals might help prevent the spread of disease.

ANI