Do you have an old birdcage that you can put out with seed in the bottom of it? If you do, do that, tie a string to the door, and run the string through a window in your house. Hold the door open, wait until he goes in to get the seed, then let go and let the door close. I actually caught a sick blue jay this way to take it to a wildlife rehabber, and being an escaped domestic bird, he'd be even less wary of the cage than the wild blue jay was. If he's hungry, he might go in right away and you might catch him immediately.
You might also be able to do this with one of the hav-a-heart traps made for rats and squirrels - he might weigh enough to trigger the door. Then you wouldn't even have to wait and watch the cage.