Well fly for short time suggests being able to fly to a certain height or for a certain time, after all, the pictures of them have really skinny raggedy wings. What about a stamina bar, you could fly until it went down, then you would have to stand still for a while for it to recharge. Gliding wouldn\'t decrease it, so you couldn\'t use it up in the air and then die. Plus, you could train and make the stamina bar bigger, or go down slower.