Science

Feathered Friends for Life—or Not

Birds make new pals when circumstances force it, but don't expect them to buddy up for the long haul.

Do birds use icebreakers?

In a room full of strangers, you’d most likely make a beeline for the friends (or frenemies) you recognize, just to avoid making small talk with a bunch of people you don’t know. Scientists have recently observed a similar bias in birds, finding that when they’re forced to spend time with strangers, they’ll get chummy—but only for a little while.

To study this behavior, researchers from the University of Oxford in England had to do some serious social manipulation. They banded hundreds of Blue Tits, Marsh Tits, Coal Tits, Great Tits, and Eurasian Nuthatches with radio tags, and set up feeders full of sunflower seeds to get the birds to mingle.

Initially, they let the birds hang out on the feeders at their whim. But then they shook up the laissez-faire community by replacing the original feeders with six “Big Brother” boxes, each equipped with a radio frequency antenna to identify the anklet on each alighting bird. If a bird’s band carried the right passcode, the doorway to the box would open. Birds with tags ending in an even number were able to unlock and feed from only three of the stations; birds whose tags ended with an odd number were restricted to the other three.

Because of this segregated feeding regime, birds were forced to dine with some unfamiliar faces. The researchers’ ultimatum: Either buddy up, or find a different cafeteria. The birds relented; soon they were contentedly feeding with just their even- or odd-numbered brethren.

The final test was to see if these freshly forged friendships could endure. The researchers rejiggered their setup by interspersing the V.I.P. feeders with ones that didn’t require a code to get in. Over the course of six days, they found that birds switched feeders but stuck with the same groups whose company they had shared in confinement.

Interestingly, the relationships extended to other modes of life, too. Birds seeking out nearby nesting boxes tended to pair up with members of the same species from their respective even- or odd-numbered cliques. “I think the basic message is that individuals which are forced to be together in one social context also stick together in other social contexts,” said Josh Firth, study coauthor, to Discover magazine’s Inkfish blog.

In the end, however, the researchers found that these friendships don’t last. When the Big Brother feeders were removed after three months and the birds were suddenly free to feed where they chose, it took just a week for this rigid social structure to fall apart. Soon the birds were mixing it up and socializing with birds with no regard to the groups they had belonged to before. The researchers see this as evidence of just how resilient populations are to outside disruption.

So it appears that birds like to be able to choose their own friends. Because let’s be honest: No one wants to be forced to spend time with individuals they don’t like. That’s what in-laws are for.