As early as 10,000 years ago, humans kept pigeons in captivity.

Seeing their meat as a protein source and their nitrogen-rich poop as the perfect fertilizer, humans brought pigeons into captivity as far back as 10,000 years ago. We then tapped into other traits. Pigeons are naturally speedy and possess a powerful homing instinct that drives them to navigate long distances back to the location they consider “home.” So we began developing pigeon posts and breeding and training them for racing. In a hobby called “pigeon fancying,” people selected for traits like head plumage and fabulously feathered feet. As we carried pigeons around the world, they escaped or were released, forming the wild urban flocks we're familiar with today.