The place my mom has is next to what I'll call an ephemeral pond. It was there in years where we had decent rainfall and would persist most of the year during good times. When it was present, the Red-wing Blackbirds nested there, as they love the water. When they were living there and a Hawk made the mistake of flying through their turf they would gang up on the Hawk, swarming it, screaming and cursing up a storm, and a few times even ripping feathers out of those that strayed too close to their homes! The Hawk always bailed as quickly as possible once it begun. Its cover had been completely blown, destroying all chance of it successfully hunting, plus it had to deal with a swarm of pissed off little noise-makers.
I used to laugh and enjoy the whole spectacle immensely because it meant *I* didn't have to spend my energy running the hawks out.
I'm not sure if other Blackbird species are this offensively defensive when it comes to Hawks interloping into their territory, but it wouldn't surprise me. Starlings hate Hawks and drive them out too, but they will thieve Chicken eggs. I've also seen Crows and Ravens harass the living hell out of all kinds of Hawks and Owls, too. The Corvid family to which they belong is full of clever, and often ornery, stubborn, and persistent types.