I wonder why:

I wonder why birds fly. Was it a natural evolution for predator avoidance or did they strike a bargain with someone? If it were the latter, what did they trade for their gift of natural flight? Perhaps they traded lifespan..."I'll give you the gift of flight, but instead of living 200 years, you'll only live to be 15." Nah, not likely. Different birds live to be different ages. Maybe they traded plumage. "I'll give you the gift of flight, but instead of being stunningly beautiful, you'll have to all drab and brown." Nah, the peacock has relatively nice plumage and I'm pretty sure they fly. Ah ha. I know what it is. They must have given up most of their intellect. After all, I doubt you've ever heard someone being nice call someone else as a "bird-brain". :-)