Monk parrots have been shown to lose social status during absence

Monk parrots take this saying very seriously, according to new research from the University of Cincinnati.

Biologists have found that these noisy and sociable parrots risk losing their hard-earned social status if they are absent from their flock for just eight days. The researchers found that the higher-ranking birds lose prestige the most during their short absences.

The study has been published in the journal Behavioral ecology.

UCLA scientists studied three groups of captive monk parakeets in 2021 and 2022. The study, led by postdoctoral researcher Annemarie van der Marel, focused on testing whether social history is a critical component in structuring how parrots gain ranks and maintain ranks within their groups. The researchers were able to determine the status of each bird in the flock dominance hierarchy by observing their interactions and quantifying rank using aggression networks.

Van der Marel, a former UCLA postdoctoral researcher, is now a postdoctoral fellow at the Pontifical Catholic University of Chile where she conducts research on social mammals. But monk parrots are never out of her mind. Feral macaws nest outside their home in Santiago.

“They’re loud. They’re very sympathetic to some group members but can be very angry towards others. There’s a lot of social drama,” said Van der Marel.

The field crew recorded 100,000 fights over the course of two years of trials. They record a lot of data about the birds’ efforts to increase or defend their social status, said Elizabeth Hobson, a behavioral ecologist and assistant professor in the UCLA College of Arts and Sciences.

“Monk parrots are very feisty. They fight all the time,” Hobson said. “They generally don’t have sporadic fights, they just bicker constantly.”

Usually, the aggressor will move to another bird and threaten to peck it. Often, the other bird will flee before the interaction can become physical.

“We call it exodus. It’s clear who are the winners and who are the losers,” Hobson said.

Once a hierarchy was formed in the social groups, the researchers removed birds of different social status for eight days before returning them and observing their reintegration into the flock.

“We surmised that if there was something substantial about the bird which gave him such a high rank, it should have been able to return to the waltz and regain his former rank with ease,” said Hobson.

Unlike some animal societies where the largest individual is often dominant, the researchers found that size didn’t matter much among monk parakeets. Instead, they advance through sheer force of will.

“It’s really amazing to see a bird that has risen all the way to the top of the hierarchy be demoted so dramatically after being out of the group for just one week,” Hobson said. “Because this loss of rank is not related to anything we measured about the birds, we think the loss of rank is most likely the result of a change in social history, perhaps because the removed birds were absent and could not fight to hold on to their place in the hierarchy.”

The new study also found that highly rated birds had much more difficulty reintegrating into their previous groups. While lower-ranking birds also experienced a decrease in status, it was not to the same extent as higher-ranking birds.

“The group treats them very differently,” Hobson said. “Generally, when we reintroduce the higher-ranking bird, the group responds with a lot of aggression toward that reintroduced bird. A lot of bullying happens.

“But when we reintroduced a medium or low-ranked bird, we didn’t see the kind of aggressiveness focused on that bird as we saw on the higher-ranked bird,” she said.

It’s possible, Hobson said, that flock members don’t view lower-ranking birds as a threat to their status.

“When we take out a bird, there is a void of energy and everything shifts to accommodate it,” said Chelsea Carmenito, co-author and doctoral student at UCLA. “When this bird suddenly returns, the birds above will not want to give up their higher rank and will defend their position.”

Carminito studies the behavior of monk parakeets to learn ways to improve their care and the care of other social birds in captivity, zoos, and research centers.

“My interest is how to reduce stress in captive situations when you have to remove a bird,” she said.

Van der Marel said the flock’s social structure quickly adapted to the absence or loss of a single bird. In the wild, flocks sometimes lose members to predators or disease, so the remaining birds may be adaptive. Less common, she said, is when a high-status bird returns to the flock after a long absence, possibly due to injury. These reintroductions seem to cause more chaos in the social group than removals.

“Monk parrots have a very complex social system and they show a lot of cognitive complexity,” van der Marel said.

From Hobson’s previous studies, the researchers learned that monk parrots in captive groups can have a deep understanding of their social system and can use this to be selective in choosing which birds to aggressively target.

“They spend a lot of time and energy watching each other’s fights and remembering the results,” Hobson said. “They seem to be aware of their rank and the position of others in these hierarchies.”

In dominant hierarchies, the higher rank often grants better access to food and other resources. It’s not clear what advantages they provide monk parakeets in the wild, Hobson said, as social birds are difficult to study.

Hobson studied several dozen wild birds that she captured and tagged in Argentina, but they clustered with many others, making it difficult to say where they fit in the larger social structure.

“In Argentina, people call the parrots la plaga,” Hobson said, which means the plague. And there are thousands and thousands of them…”

In her biology lab, Hobson uses partridge quail as a model system to study relationship formation and social structure. This year it also added aquariums for colorful bettas, which may also be able to use social information to regulate their social interactions and aggression.

“The more similar we can make the experiments and the analytical approach, the more we can compare the community in apples with the way apples across species,” Hobson said.