City birds fly away on average about one meter sooner when a woman approaches them than when a man approaches them. The unusual result was found in a study in five European countries and was published in the scientific journal People and Nature. The authors emphasize that they cannot yet pinpoint a specific reason for the observed difference.
The study was conducted in city parks and green spaces in the Czech Republic, France, Germany, Poland and Spain. Four women and four men, all ornithologists, participated in it. They approached the birds in a straight line at a normal and constant speed until the animal flew away or moved away. This distance is known as the flight initiation distance.
The researchers recorded 2,701 responses from birds of 77 species. The main analysis used 2,581 observations of 37 species, including blackbirds, jays, magpies, great tits, house sparrows and pigeons. The average flight distance was 8.5 meters when a female approached and 7.5 meters when a male approached.
The conditions were equal
To limit the influence of other factors, the scientists selected participants of similar height and dressed them in similar colors. Observers alternated the order in which they began the approach, so that the birds' habituation to a particular person would not affect the result.
The difference remained even after taking into account the initial distance, flock size, sex of the observed bird, vegetation and characteristics of the urban environment. It was visible in both male and female birds, and the result was similar across countries.
More questions than answers
The authors write that “the mechanisms or reasons behind this pattern are unknown“. Among the possible explanations are differences in gait, body movement, subtle features in the appearance or smell of the approaching person.
The scientists do not completely rule out the role of smell, but consider it less likely, since the participants did not touch the birds and approached them from a distance. Further research is needed to determine whether birds recognize human gender through visual, motor, or chemical cues.
The results do not mean that all birds react the same way to every human encounter. Rather, they suggest that urban birds may be sensitive to much more subtle differences in the behavior and appearance of approaching humans than previously thought.
Sources: btvnovinite.bg, phys.org