What is my cat saying?

There is something really weird going on with my cat. She is about four months old. She sits in the window sill and there is an old tree just outside the window. Squirrels and birds are all up and down this old half dead tree.

My kitty sits in the window and talks in some kind of weird language to them. She seems to be chirping at the birds. She is not meowing, but making a clickity clackity chirp sound. What on earth is she doing! I am going to try and video her doing this because it is way too funny!!

What is she saying to them?