Human Hair Is Causing Pigeons Toes To Drop Off, Study Finds
Pigeons with mutilated feet are a common sight in cities around the world and it turns out it could be due to the humble human hair.
Scientists have often blamed the missing toes on infection or a reaction to chemical pollution but a new study challenges those theories.
A team of French researchers investigated the extent of the damage at 46 sites around Paris and found that toe mutilation tended to increase with the density of hairdressers.
“Hair cut at the hairdressers are removed by garbage collection services with household wastes, and during this process, we could expect residual cut hair to end on the sideways and pavements,” Frédéric Jiguet and his team at the National Museum of Natural History in France wrote.
The researchers say that pigeons often lose digits which get stuck in the hair, a phenomenon known as "stringfeet".
"When they walk, they can trip on strings or hair," Jiguet told CNN.
"The string might just fall, but sometimes it forms a knot around a toe, and in the end, the toe dies and falls off".
To confirm, a pigeon should have four toes or claws.
The study also found that foot health had nothing to do with how old a pigeon was, or how dark its feathers were.
Infection and chemical pollution weren't totally ruled out with the study showing that pigeons also have fewer toes in areas with more air and noise pollution.
Simply put, "the more human activity in an area, the less toes pigeons have" and "the more green spaces, the more toes they have," according to Jiguet.
The study was published in the journal Biological Conservation.