Study reveals how birds carefully form new friendships

By Stephen Beech

Birds "test the waters" first with potential pals, shows a study.

American researchers found that monk parakeets gradually approach a stranger.

They take time to get familiar to avoid increasingly dangerous close encounters, according to the findings.

Study lead author Claire O’Connell said: “There can be a lot of benefits to being social, but these friendships have to start somewhere.

“Many parrots, for example, form strong bonds with one or two other birds.

"Partners often spend most of their time together, preen each other or sometimes form reproductive relationships.

“Generally, maintaining these strong social bonds is associated with decreased stress and higher reproductive success.”

But she explained that making the first contact carries risk, especially when animals are unfamiliar to one another.

O’Connell, a doctoral student in the University of Cincinnati’s College of Arts and Sciences, said that birds that don’t welcome a newcomer’s attention can react aggressively, which may lead to injuries.

She and her colleagues combined groups of wild-caught parakeets in a large flight pen.

Some parakeets were strangers to each other.

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The team collected data on when and how new relationships formed by studying how close the birds approached over time and which birds groomed each other or engaged in other friendly behaviors.

They then analyzed more than 179 relationships using computational methods and statistical models to determine whether relationship formation followed the pattern predicted by previous studies exploring the theory of testing the waters.

O’Connell said: “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."

The findings, published in the journal Biology Letters, showed that strangers were more likely to approach each other with caution compared to birds they knew.

Stranger birds took time to share space before eventually perching shoulder to shoulder, touching beaks or preening others.

Some escalated further to sharing food or mating.

The research team said their findings were comparable to a 2020 study of vampire bats that found that newcomers likewise test the waters, gradually escalating from social grooming relationships to sharing food with trustworthy partners.

O’Connell said: “What’s really fascinating about testing the waters is how intuitive it feels."

She added: “I can definitely relate.

"I started observing the parakeets shortly before I moved to Cincinnati to start graduate school.

“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.”