Melanie, cool seeing the hawk in the yard! That group of large black colored birds looks a lot like Grackles to me. They may be either the Common Grackle or the Boat-tailed Grackle. We get large flocks of them over here at certain times of the year.
Common Grackle: http://www.allaboutbirds.org/g... https://en.wikipedia.org/wiki/...