I was out in the backyard early in the morning and I could hear the Blue Jays going nuts in their calls. I kept searching in the trees behind my backyard, and I finally saw what they were so upset about.
If I’m not mistaken, this is a Sharp-Shinned Hawk. It was clearly hunting, scanning towards the ground and lower tree limbs for other birds. The Blue Jays kept dive bombing the hawk, and finally it flew away.