Urban Birds Seem to Be More Fearful of Women Than Men—and Scientists Don’t Know Why
The study examined 37 bird species in cities across five European countries. The animals allowed men to get about three feet closer than women, on average, before flying away
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In the 1964 film Mary Poppins, a message of generosity comes through in the lullaby “Feed the Birds.” The titular nanny sings the story of the “bird woman,” who sells bags of crumbs while imploring passersby to “feed the little birds, show them you care.”
Unfortunately, new research suggests the birds might not always appreciate that generosity—particularly from certain people. In a study published in the February issue of the journal People and Nature, scientists found that feathered, flying creatures surveyed in several European cities were more fearful of women than men.
The findings aren’t just a curiosity. The team says that considering differences in the people observing animals could change how scientists conduct behavioral studies of wildlife.
“As a woman in the field, I was surprised that birds reacted to us differently,” says study co-author Yanina Benedetti, an ecologist at the Czech University of Life Sciences Prague, in a statement. “This study highlights how animals in cities ‘see’ humans, which has implications for urban ecology and equality in science. Many behavioral studies assume that a human observer is neutral, but this wasn’t the case for urban birds in our study.”
Did you know? Covid-19 affected some urban birds’ beaks
Dark-eyed juncos living in Los Angeles evolved longer beaks during lockdowns, but the features shortened in more recent years. Researchers suspect this happened because the animals lost access to food scraps tossed by humans during the height of the pandemic.
Benedetti and her colleagues studied the feathered animals in seven cities across five European countries: the Czech Republic, France, Germany, Poland and Spain. In each experiment, observers of different genders—but similar heights and clothing—walked in a straight line toward birds and noted how far away they were when the animals took off. They called this the “flight initiation distance.”
The four men and four women observers—all expert ornithologists—recorded a final dataset involving 37 bird species. Between April and July of 2023, they gathered data from nearly 2,600 interactions in parks and other urban green spaces.
On average, the birds let men get about three feet closer than women, the team found. The pattern was consistent in every country, and it held across bird species with different behaviors.
Common pigeons, for example, were more tolerant of all humans and took off when the researchers reached an average of 11.5 feet away. European green woodpeckers, meanwhile, seemed more skittish and flew away when observers were, on average, 53 feet away. Both species still fled earlier when women approached.
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Despite the consistent results across species and geography, the researchers don’t know why city birds appear to be more fearful of women. They speculate that the different reactions might be due to distinct scents, gaits or body shapes but note that more observations controlling for those variables is necessary to confirm those ideas.
“We need to increase the number of human observers, thereby increasing the robustness of the results,” says study co-author Federico Morelli, an ecologist at the University of Turin in Italy, to the London Times’ Adam Vaughan.
Others are wary of the findings, since they are preliminary.
“Until we have a good reason to hypothesize such differences, I remain a bit skeptical,” says John Marzluff, an ecologist at the University of Washington who wasn’t involved in the new study, to Live Science’s Kenna Hughes-Castleberry. “But I am not at all skeptical that birds pay a lot of attention to us and respond to humans in ways that are important. We just need more research here to better understand why this effect was so consistent.”
Although the research team has many mysteries to unravel, they are confident they observed a real phenomenon.
“I fully believe our results, that urban birds react differently based on the sex of the person approaching them, but I can’t explain them right now,” study co-author Daniel Blumstein, a biologist at the University of California, Los Angeles, says in the statement. “We used bleeding-edge comparative analysis techniques that showed our findings were consistent across cities and species, but we simply don’t have a conclusive explanation yet.”