These Birds Will Switch Companions to Earn Food but Stick With Family, Study Suggests

Jackdaws, cognitively complex relatives of crows, have intricate social dynamics and mate for life

a profile of a jackdaw; bird that looks like a crow with some grey on the side of its head and neck
Jackdaws are social birds that mate for life and breed in colonies. Keith Marshall via Getty Images

For jackdaws—black and gray relatives of crows—family comes first, according to a recent study published last month in Nature Communications.

Scientists put these cognitively complex birds to the test to see how their social relationships might change in response to food rewards. To get enticing mealworms in an experiment, wild jackdaws quickly learned to shift their companions to receive the tasty snack. But when it came to offspring, mates or siblings, the jackdaws chose to stay with their family over getting the food.

“Jackdaws are very loyal birds,” Alex Thornton, a co-author of the paper who researches cognitive evolution at the University of Exeter in England, tells CBC Radio’s “As It Happens” host Nil Köksal. “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.”

As remarkably social birds that often forage in groups, jackdaws, named for their “jack-jack” call, have complex social dynamics. The birds, native to Europe and Asia, breed in colonies and retain associations with their parents and siblings, even after fledging.

“Beyond their strong relationships, they have lots of other associations,” Thornton tells the Guardian’s Steven Morris. “There’s quite a lot to remember.”

Scientists wanted to examine whether these birds could learn to change their relationships based on different social outcomes and, in doing so, learn more about how individual behavior impacts group dynamics.

To test this, they randomly assigned hundreds of jackdaws to either “group A” or “group B.” The jackdaws all had ankle bands outfitted with tiny tracking chips, like the ones given to pet dogs and cats, due to their inclusion in other research, reports Sheena Goodyear for CBC Radio. Programmed feeders would then read the chips to detect which group the birds belonged to as they came to feed.

If the birds were in the same group, the feeder would dispense grain and mealworms, “which are like truffles for jackdaws,” Thornton says to “As It Happens.” But if the birds arrived alone, they were given only the low-quality grain. If they came with a jackdaw from the other group, the feeders would remain shut entirely.

The experiment showed the corvids could quickly piece together how to ditch birds from the other group in order to maximize mealworms. Based on the team’s analysis, this reorganization appeared to be intentional: The proportion of successful pairings at the feeder—55.4 percent—was too high to be explained by random chance, per the paper. Scientists aren’t sure whether the birds maintain these associations when away from the feeder.

But among family members, their pairings “were unaffected,” whether or not the birds were assigned to the same experimental group, the authors write.

Jackdaws mate for life, and partners share nest-building and young-rearing responsibilities. Thornton tells CBC Radio these long-term relationships may be too critical to the birds’ survival and reproduction to cast aside for some mere mealworms.

“These results have important implications for our understanding of the evolution of intelligence as they show that being able to track and remember information about social partners can bring benefits,” Michael Kings, a researcher at the University of Exeter and co-author of the study, tells the Guardian.

Animals rarely form non-familial relationships in the wild, as Claire O’Connell, a behavioral ecologist at the University of Cincinnati who wasn’t involved in the study, tells CBC Radio.

“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,” she tells the publication.

The study is part of the Cornish Jackdaw Project, which began observing the birds’ cognition and social patterns in 2012 and includes more than 2,500 tagged jackdaws.

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