Pigeons with mutilated feet are a common sight in cities, and it turns out that they are being cut off by human hair that has been poorly disposed of
Source:
https://www.newscientist.com/article/2223395-pigeons-are-having-their-toes-amputated-by-waste-human-hair-in-paris/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home