Wondering...

Why is it that when I walk past
a flock of birds
they all take off unanimously
with that "whish"
that I adore
and then, as one entity,
land in the tree.
Why do they all go to the same tree?
How do they know where to land
before they take off?
Do they have assigned branches?
Why don't they run into each other?
It is for this reason,
as well as that rapturous sound of wings
that sends me running through parks of crows
screaming at the top of my lungs
just for the hell of it.