Wild parrots copy their friends when deciding whether to try new foods, study finds

A sulphur-crested cockatoo eats a red-colored almond as part of the experiment. (Julia Penndorf via CNN Newsource)

Human children often copy their friends’ preferences for toys or clothes, while adults are prone to jumping on popular diets or lifestyle trends. Now it turns out that this sort of imitation is not unique to our species, as wild parrots learn to try new foods by copying their peers, a new study suggests.

Animals living in urban environments often encounter new or unusual resources, such as garbage, street trees, exotic plants or invasive species.

For animals in these ever-changing cityscapes, expanding their diet to include novel food items can be crucial, according to the study published in the journal PLOS Biology on Thursday.

However, they are often wary of trying unfamiliar food, as it could be poisonous to them or carry parasites, said the researchers in Australia, Germany, the US and Switzerland.

One tool some animals use to find out whether it’s worth taking the risk is social learning, which they do by observing or interacting with others or their items.

This strategy has been seen among wild jackdaws and wild rooks. Lab studies on rats in Norway have also shown that rats can acquire food preferences by smelling the breath of clued-up individuals.

However, social learning strategies have been little studied in the wild compared to labs, according to the researchers.

To find out if wild parrots use the technique, the researchers studied more than 700 wild sulphur-crested cockatoos across five roosting communities in central Sydney.

Two parrots from a Balmoral Beach community and two from a Clifton Gardens community were trained –– after being initially very averse –– to eat almonds that were artificially dyed either blue or red, respectively.

Then, a food dispenser containing both colored almonds was introduced into the communities in daily sessions for 10 days.

After seeing the trained parrots take them, curious individuals started eating the colored almonds in the Balmoral Beach community within seven minutes, and in the Clifton Gardens community in less than one minute, according to the study. In both roosts, the parrots ate both colors from day one.

In a third community, where there were no trained cockatoos, it took four days for the parrots to try the novel food items. But after one parrot –– who had moved from the Balmoral Beach community, where she had watched others eat them 130 times –– took the risk, 15 other parrots also ate the almonds within 10 minutes.

The researchers expanded the experiment to include two more roosts.

By the end of the 20-day experiment, 349 individuals across five communities were eating colored almonds, according to the study.

Young parrots are ‘very conformist’

The researchers also looked at whether the parrots were selective in who they copied and found “a clear sex bias,” lead study author and behavioral ecologist Julia Penndorf, a postdoctoral researcher at the University of Exeter in the UK , told CNN on Thursday.

Males were more likely to influence the behavior of other males than the behavior of females, according to the study. Female parrots were more likely to change their behavior based on social information, regardless of the age or sex of the individuals they observed.

“Perhaps even more intriguing is that juveniles were very conformist,” and so would copy the choices of the majority, which was “quite funny to see” since the same trend can be seen among human children, said Penndorf, who conducted the research when she was a postdoctoral research fellow at the Australian National University and the Max Planck Institute of Animal Behavior in Germany.

Adult parrots, however, “were more interested in what their social associates would do,” rather than just going with the majority, she added.

Since juveniles move around more, copying what the locals are doing “might be very important to quickly learn about novel opportunities that are safe,” similar to how humans might pick a restaurant by seeing which one has the most diners, Penndorf said.

“Sulphur-crested cockatoos have done very well in urban areas across Australia, and one key to their success is that they carefully take note of what other cockatoos are doing,” Michael Chimento, a postdoctoral researcher at the University of Zurich in Switzerland and the Max Planck Institute of Animal Behavior, told CNN.

“Interestingly, younger cockatoos (more-so than older cockatoos) continue to update their knowledge, and might change their preferences based on what others are doing. This is like how we might, in the moment, change our order at a restaurant depending on what our friends ordered,” Chimento, who was not involved in the study, added.

“This study raises the possibility that this conformist tendency might change across the lifetime, perhaps peaking at developmental stages when individuals most need to quickly acquire local knowledge,” psychologist Rachel Harrison, an assistant professor at the UK’s University of Durham, who was not involved in the study, told CNN.

The parrots also appeared to employ similar techniques for opening the nuts to those of the peers they spent the most time with, Penndorf said, noting that the researchers did not test this directly.

Penndorf added that some of her colleagues are already looking at whether social learning is a strategy used across a wider area, like an entire city.

Amarachi Orie, CNN