[Aeneas]

Not sure if that is the right word. Looking for someone who knows something about birds. I have no knowledge of bird watching (of the feathered variety anyway) other than craning my neck and pointing.

Anyways we have a couple of hawks (I am only guessing they are hawks. Definetly a bird of prey, has a great calling sound) that we frequently see circling above our houses; forest very close by.

Sometimes these black birds, much smaller than the hawks will appear to chase them. Could be Blackbirds for all I know. They are almost all black but with two strips one yellow one red/orange where the wing meets body. The black birds fly above the hawk and seem to attack/land on the Hawk's back.

So my query is, what are the black birds doing? If they are attacking the hawk, why doesn't the Hawk do something about it. The hawks usually fly off to the forest, the black birds back to the marshy area by a large pond.
Are they defending territory? Are they grooming the hawk?

Just curious.