Human beings are the only animal that thinks they change who they are simply by moving to a different place. Birds migrate, but it's not quite the same thing.
We have an uncanny ability to make birds do what we want them to do. In Blood Simple there's a shot from the bumper of a car and it's going up this road and a huge flock of birds takes off at the perfect moment.
Like dogs in a wheel, birds in a cage, or squirrels in a chain, ambitious men still climb and climb, with great labor, and incessant anxiety, but never reach the top.
There are joys which long to be ours. God sends ten thousands truths, which come about us like birds seeking inlet; but we are shut up to them, and so they bring us nothing, but sit and sing awhile upon the roof, and then fly away.
Turkeys, quails, and small birds, are here to be seen; but birds are not numerous in desart forests; they draw near to the habitations of men, as I have constantly observed in all my travels.