Friends with benefits? These birds make strategic connections to get better food

Sometimes getting what you want in life comes down to who you know — a lesson a group of wild jackdaws in England learned rather quickly.

In an experiment, the birds learned to ditch old friends and form new social connections in pursuit of tasty treats. 

But it appears blood is thicker than water for jackdaws as a free supply of delicious mealworms wasn’t enough to entice them to abandon their lifelong mates or immediate family members. 

“Jackdaws are very loyal birds,” Alex Thornton, a professor of cognitive evolution at the U.K.’s University of Exeter, told As It Happens host Nil Köksal. 

“In the study that we’ve just published, we show that they stick with their close relationships through thick and thin — even though they’re much more savvy when it comes to adjusting their other relationships.”

The findings were published on Monday in the journal Nature Communications.

Social engineering via automatic feeders

The study is part of the Cornish Jackdaw Project, in which researchers have been observing the behaviour of thousands of wild jackdaws across several colonies in Cornwall for about 12 years. 

The birds in the project have ankle bands equipped with transponders, like the kind used in microchips to keep track of pet cats and dogs.

“We then put out automated feeders out in fields in the countryside. So whenever the birds land on one of these feeders, the feeder will automatically detect who that bird is,” Thornton, a co-author, said.

The feeders, he said, come in pairs. In this experiment, one side distributed low-quality grain, while the other dispensed “really tasty mealworms — which are like truffles for jackdaws.”

The researchers divided the birds into two groups: A and B. They then programmed the feeders to only open under certain conditions: 

For a solo bird, only the grain door would open. The mealworm door remained shut.  If a group A bird and a group B bird visited together, neither door would open.  If two birds from group A or two birds from group B visited together, both doors opened.

The birds, Thornton said, caught on quickly. Old friendships dissolved and they started showing up with new pals from the correct groups to maximize their mealworm access. 

WATCH I From solo to success at an automated feeder:

Jackdaws learn they can get better snacks with the right social connections, study finds

In this footage from a University of Exeter study, a solo jackdaw’s tag only gives it access to a feeder with low-quality grain. But when another tagged bird joins in, the feeders start dispensing much tastier mealworms.

“People often argue that being able to navigate the vagaries of living in a complex social life is one of the things that’s driven the evolution of intelligence in humans and some other animals,” he said.

“And so in this experiment we wanted to see, well, if we changed the value of hanging out with different individuals, can they learn this?… And it turns out they can.”

Family first

But the automatic feeders did not pry the birds apart from their mates, children, parents or siblings, Thornton said. 

“These guys seem to stick together through thick or thin, even if it means missing out on some short-term rewards,” Thornton said. 

Not only do jackdaws mate for life, but they are genetically monogamous, which means they have all their offspring together. 

“It’s not really worth ditching them for the sake of a few mealworms,” Thornton said. 

Claire O’Connell, who wasn’t involved in the study, called it a “fascinating” look at how and why animals form non-familial relationships — a rare phenomenon, and one she says scientists are just beginning to understand. 

“Although they can be beneficial in some contexts, investing time and energy into unrelated individuals can be a risky social strategy, especially if long-term, stable relationships are important for survival and reproduction,” O’Connell, a PhD candidate in biological sciences University of University of Cincinnati, told CBC in an email. 

The findings, she said, highlight how jackdaws use their cognitive skills to navigate complex social situations. 

“Jackdaws are remembering previous experiences with others and using that information to make strategic decisions about how, when, and why they form or maintain supplementary relationships.”

But are they real friends?

Thornton says the researchers don’t know whether the birds who learned to feed together actually maintained those relationships away from the feeders.

“And it’s not really clear whether or not you would expect them to,” Thornton said. “You might have friends who are great to go to the pub with but might not be very useful to help you with a work assignment, right?”

“That’s something that we hope to look at in future work.” 

If these transactional relationships have you feeling cynical about jackdaws, Thornton suggests you look inward.

“They’re adjusting their relationships in quite a savvy, strategic way to make sure they get the best rewards,” he said.

“If you think about how we manage our relationships, you know, our relationships are quite strategic — even if we’re not necessarily aware of it.”