Amputated
Pigeons in city centres aren't an uncommon sight. A wander through Paris, and you might notice a high proportion of them are missing toes!
There are many theories behind the cause of this; however, pigeon experts have also noticed that birds often have string or human hair wrapped around their toes and feet. The hair/string can eventually tighten, cutting off circulation and leading to tissue death and the toe falling off.
This observation prompted Frédéric Jiguet at the National Museum of Natural History in France and his colleagues to study the relationship between the foot health of pigeons and possible sources of these hairs or strings.
They studied the number of foot mutilations in pigeons found at 46 sites across Paris, and how these related to different features in the environment.
They found Pigeons were more likely to have mutilated toes in city blocks where a greater number of people lived. Also, the greater the number of hairdressers on a city block, the higher the chance pigeons were to have lost toes
"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," the authors wrote.
If the birds can't untangle themselves, the hairs begin garroting the toes causing what is known as "stringfoot".
The good news is that having green spaces near the city blocks seems to protect the pigeons from losing toes.
The study also found that foot health had nothing to do with how old the pigeons were. Nor did it have any relation to how dark their plumage was, which is typically a marker of of how resistant they are to pathogens.
Read more: https://www.newscientist.com/article/2223395-pigeons-are-having-their-toes-amputated-by-waste-human-hair-in-paris/#ixzz65poznGW0