How parakeets make new friends in a surprisingly human way

The findings appear in the journal Biology Letters.

Why Social Bonds Matter for Parrots

"There can be a lot of benefits to being social, but these friendships have to start somewhere," said Claire O'Connell, the study's lead author and a doctoral student in UC's College of Arts and Sciences.

O'Connell worked with UC Associate Professor Elizabeth Hobson, former UC postdoctoral researcher Annemarie van der Marel, and Princeton University Associate Professor Gerald Carter. She explained that many parrot species develop strong, lasting relationships with one or two partners. These close companions often spend much of their time together, groom each other or even form reproductive partnerships. According to O'Connell, strong bonds like these are often linked to reduced stress and improved reproductive success.

The Risks of Making First Contact

Despite the advantages of close relationships, approaching a stranger can be dangerous. O'Connell noted that birds uninterested in a newcomer's attention may respond aggressively, creating a real possibility of injury.

To better understand how these initial interactions unfold, researchers placed groups of wild-caught monk parakeets together in a spacious flight pen. Some individuals had never encountered each other before. The team recorded when new connections formed by tracking how close the birds allowed each other to come and identifying which pairs engaged in grooming or other friendly behaviors over time.

Tracking Relationship Development

More than 179 relationships were analyzed with computational tools and statistical models. The goal was to determine whether the progression of new social ties matched expectations from earlier work on the idea of testing the waters.

"Capturing the first moments between strangers can be challenging, so we were really excited that our experiments gave us the chance to observe that process up close," O'Connell said.

The data revealed that unfamiliar birds were far more cautious when approaching each other than when interacting with birds they already knew. Over time, however, many of the stranger pairs began sharing space more comfortably and eventually perched together, touched beaks or groomed each other. A few pairs progressed even further, sharing food or mating.

A Pattern Seen in Other Social Species

The results mirrored a 2020 study of vampire bats showing that newcomers also test the waters, slowly progressing from grooming relationships to more substantial food-sharing partnerships with trusted companions.

"What's really fascinating about testing the waters is how intuitive it feels," O'Connell said.

She added that she could relate personally. "I started observing the parakeets shortly before I moved to Cincinnati to start graduate school," she said. "I was excited but also a little nervous about making new friends. At the same time, I was literally watching the parakeets make new friends themselves, although some did better than others. I started realizing there may be something I could learn from the parakeets."