In an Experiment, Women Scared City Birds More Than Men Did

Across five European countries, city birds generally let men come about a meter closer than women before taking flight.

An international research team tested the escape distances of 37 bird species during their breeding season in urban green spaces in Germany, Poland, Czechia, France and Spain. In each test, a person walked calmly and directly toward an individual bird.

The distance varied by species and environment, but birds on average allowed the approaching person to get to just under 10 meters. The pattern remained consistent from country to country, with birds flying away from women at an average distance of about one meter farther than from men.

The result surprised the researchers. Earlier studies had found, for example, that monkeys could respond more fearlessly to women than to men. The men and women in the walking tests were similar in size and wore similar clothing, so their appearance did not offer an obvious explanation.

The researchers also ruled out the smell of blood as a likely deterrent because the women did not take part during menstruation. Writing in People and Nature, they suggested the tendency could have been inherited from birds that survived earlier threats from hunter-gatherers. Men are generally assumed to have done most hunting, but the researchers raised the possibility that women may have caught small animals, including birds, more often than previously thought.