How smart is a bird?

I find myself wondering how smart your average back yard Cardinal is....

For the past few nights, right at dusk, a male cardinal has come to sit on my deck railing.  Where he proceeds to chirp... and chirp... and chirp.  Eventually, I give in and go lay some seed down on the deck railing.  As I step outside, he flies up to the tree and then comes back when I step inside.

He doesn't eat the seed... he may pick at one or two but then he goes right back to chirping.

I think this bird likes torturing my cats.