You and your partner are hungry, but your favorite pizza parlor will only let your mate in to dine. What do you do? If you’re a great tit (Parus major), a songbird found from Europe to Northern Asia, you wait by yourself, even though theoretically you would be better off looking for food elsewhere, scientists have discovered. To find out whether the small birds, pictured above, prefer food or hanging out with their mates, the researchers conducted a series of experiments with a long-studied population of wild great tits in the United Kingdom. They set up 12 feeding stations that would only open to great tits wearing particular radio frequency identification (RFID) tags. Half of the stations unlocked only to birds with even-numbered RFID tags; the others opened to great tits wearing odd-numbered tags. The scientists randomly outfitted 10 mated pairs of the birds with identical tags so that they could enter the stations and feed together; and seven pairs with incompatible tags, so that one was locked out. They followed the birds for 90 days, recording 66,184 visits to the feeders. The pairs with the incompatible tags spent almost four times longer at the prohibited feeders than did the compatible pairs—even though one bird was stuck outside, the scientists report today in Current Biology. Other studies have shown that birds may forage in flocks, despite having less to eat, because there are other benefits, such as having others to help watch for or defend against predators. But this is the first experimental study to show that wild birds will choose their mate over food—a decision that also determines where they travel and what other individuals they associate with, which could affect their social rank, the scientists say. Many of the locked-out birds learned a new trick, too. After a great tit with the correct RFID code entered a feeder, the door didn’t slam shut for 2 seconds—just enough time for one of the incompatible birds to slip in and join his sweetie.?