Everyone that's seen a pigeon raise your hand.
Now, everyone that's never seen a baby pigeon lower your hand.
Notice how few hands are left up? Why is this, you ask? Lacking better scientific evidence, let me explain it by asking two more questions:
Have you ever seen a fat pigeon? Yes? Okay, ever see one so fat it couldn't fly? No?? Of course not!
Pigeons are like amoebas in that they reproduce asexually. You see, when a pigeon reaches a certain size after gorging itself on fattening tourist fare, it splits into two smaller, hungrier pigeons. This is why you see so many at heavily-trafficked tourist destinations like Piazza San Marco in Venice. It also explains that, while you may see a few corpulent pigeons, you'll never see one so morbidly obese that it cannot fly.
