I just threw out some old pumpernickel rye bread. They are straddling the fence and won't come down. Birds don't like dark bread or chocolate cake. I wonder sometimes if they are color blind. What I do now is I get a slice of white bread and when they swoop down for that that's when they find the black bread and eat it. They also avoid the food if they sense a cat's around.
There are some 'tough' blue jays in my neighborhood, who love nothing more than to taunt my cats ;-D