If you live in the city, you likely see a lot of pigeons, and you likely see a lot of pigeons that could use a pedicure (if they have any toes left). WHY are pigeon feet so wonky? @TetZoo tries to work it out here:
The short answer, injuries from urban "stuff" - but I think there are still more questions! Why so many pigeons and not other urban birds, like crows?
Read more here, where pigeon experts Dr. Haag-Wackernagel and Dr. Lisa Jaquin discuss how fibers get tangled in pigeon feet and cause all kinds of problems (thanks to SavorTooth for that tip!).