Male Birds Choose Friends and Mates with Similar Personalities

The old saying that “opposites attract” doesn’t seem to hold true for the great tit.

New research, published in Ecology Letters, suggests that males seek the company of other fellas with the same personality. Shy birds usually join flocks of other shy birds, while their bolder tits prefer to flitter between several flocks and interact with lots of individuals. Timid males also have fewer “friends,” but both shy males and females have stronger personal relationships than their extroverted counterparts, the researchers found.  

The study was conducted in Wytham Woods, near Oxford, where the great tits have been studied since 1947. The researchers used a new way of analyzing the social networks that linked the animals to each other. 

“There has been a lot of work describing the range of individual personalities in the great tit,” said Lucy Aplin, first author and Oxford University Doctor of Philosophy student, in the press release. “Now we are linking it to the social networks and social organization of the species, which hasn’t been done before.” 

To track the small birds, Aplin and her colleagues fitted 1017 of them with RFID tags carried inside a ring around their leg.  Sensors at 65 feeding stations in Whytam Woods tracked when each of the animals visited and the identity of its companions.  Using the records of millions of food stops at the feeders over the course of one winter, the researchers reconstructed the tits’ social networks. 

Next, the birds took a personality test.  Aplin’s team temporarily re-captured them and introduced them to a new environment (a room with a series of perches) to see how they would react.  A “shy” bird was wary and vary cautious about exploring the foreign environs.  “Bold” birds, on the other hand, moved quickly to investigate their new space.  Repeated over time, the researchers rated the tits on a personality axis from shy to bold depending on how much their explored.  Then, they compared the personality test results with feeding station interactions, and found that personality does appear to influence behavior. 

“We think shy birds might group together to avoid the more aggressive, bold birds,” said Aplin.

The researchers concluded that the more tentative, timid birds tended to engage in low-risk and low-reward behaviors, whereas adventurous birds preferred the opposite strategy. While hopping between flocks exposed them to more risk, it also allowed them to improve their social standing, and it gave them better access to valuable information on where to find more food.