Hawks in da Hood!

Small hawk lurking over a bougainvillea full of terrified House Sparrows, Jan. 11, 2011, Mesa, AZ.

I'm not that great at identifying hawks, but I've certainly seen alot of them this winter, stalking the sparrows and even dive bombing our Rock Squirrels.  So far, I'm fairly certain we've had a Cooper's Hawk, a Peregrine Falcon, an American Kestrel, and now the above Sharp-shinned Hawk.  He kept hopping all around the bougainvillea and diving into it trying to nab a sparrow.  Eventually he gave up and perched midway up a pine tree waiting for another opportunity.  In the photo below you can see how small he is in relation to the curb, and the cement block.  Given his small size and coloring I think he's an immature male Sharp-shinned.  Anyone have another guess?

Another hawk on January 18th--  Now I'm not sure if the above hawk is a Cooper's or Sharp-shinned.  This hawk was seen on tne 18th, further up a nearby tree,  and appeared larger than the one seen previously.  So, is it the same hawk or a new one, is it a Cooper's or a Sharp-shinned?  Hard to tell.