Some birds will sacrifice food if it means they will get to spend the winter by their partner's side, new research suggests.

A team of scientists found mated pairs of great tits chose their relationship over a meal in an experiment that prevented the birds from foraging in the same location, the University of Oxford reported. The birds also spent more time than usual with their partner's flock-mates.

"The choice to stay close to their partner over accessing food demonstrates how an individual bird's decisions in the short term, which might appear sub-optimal, can actually be shaped around gaining the long-term benefits of maintaining their key relationships. For instance, great tits require a partner to be able to reproduce and raise their chicks," said study leader Josh Firth. "Therefore, even in wild animals, an individual's [behavior] can be governed by aiming to accommodate the needs of those they are socially attached to."

In the experiment, the researchers used automated feeding stations that granted access only to certain individuals. The researchers could program which birds would be allowed to feed through radio frequency identification tags linked to the feeding stations. They programed the stations so that mated pairs were unable to access the same feeders. The findings revealed the birds who could not gain access to the same feeders as their mates spent significantly more time at feeders they could not access than those allowed to feed with their partners.

"Because these birds choose to stay with their partners, they also end up associating with their partners' flock-mates, even if they wouldn't usually associate with these individuals. This shows how the company an individual bird keeps may depend on their partner's preferences as well as their own," Firth said.

"Also, when birds were going to feeding stations they couldn't access because their mate was there, they learned over time to "scrounge" from those feeders by taking advantage of the fact the feeders remained unlocked for two seconds after [recognizing] a bird's identification tag. Interestingly, a relatively large amount of this scrounging was enabled by the bird's own partner unlocking the feeding station, suggesting it may be a cooperative strategy," he concluded.

The findings were published in a recent edition of the journal Current Biology.