Imagine yourself in the upper corner of a room, watching the goings-on with a bird's-eye view. There are no threats from above you, and you can see all that is happening below you. You can relax. This is what a cat's instinct tells him to do. A lion or tiger sleeping away the afternoon in the branch of a tree can rest there and will awaken quickly if there is any disturbance from below.
To work with this cat instinct, provide your cat with acceptable perching places. It could be as simple as a chair with a pillow or towel on the seat or something as elaborate as a cat tree, available at pet stores or fashioned at home out of posts and platforms. Windowsill "observation decks" can also be purchased. These allow Kitty to take catnaps while monitoring the bird feeder.
Using a little bit of imagination, you can create a cat-friendly environment of viewing and resting stations which will communicate to your cat that you understand him and that he is part of the family!