Squirrels Network Like Facebook Friends

"Squirrels have preferred companionships," he explained. "If they interact amicably more than they would just by meeting each other in the general course of things -- calculated through a complicated mathematical formula -- then they are 'friends.'"

Using the software, Manno tested what would happen to the squirrel network if individuals were removed. Random removals didn't disrupt the network much, but if more than 10 percent of the colony's important members were taken out, the network fragmented, leaving it vulnerable to collapse.

"Importance" in a squirrel colony generally refers to "adult males that are putting out feelers for sex opportunities (like Mercedes) or...adult females that are experienced at mating and want to have their choice of a bunch of males," he said.

Manno said populations of other social animals -- primates, fish, killer whales, dolphins -- could experience comparable collapses when disrupted.

Conversely, if the wildlife management resources are available, special attention to important animal networkers could strengthen animal groups, Manno theorizes.

"What I like about this paper is that it shows individuals have different relationships with others," said Daniel Blumstein, an associate professor of ecology and evolutionary biology at the University of California at Los Angeles, studies marmot social networks with colleague Tina Wey.

"While not novel, using formal social network analyses to quantify it in a free-living, non-human animal system is a relatively recent application of these statistical tools," he said.

Diseases might be better controlled in animal societies if key networkers, which might become "super-spreaders," are removed, perhaps temporarily, added Blumstein.

Wey hopes future research will also address the biological significance of social networks.

"For example," she said, "what does it mean to a ground squirrel to interact with others in the context of a network? How is this manifested in terms of biological fitness?"

"These are questions we have also struggled with, and I think there is a lot more to be done before we can answer them more comprehensively."

Related Links:

Jennifer Viegas' blog: Born Animal

Columbian Ground Squirrels

How Stuff Works: MySpace

Squirrel Sounds