Hawk harassment--it happens all the time. A Red-shouldered Hawk sits perched in a branch minding its own business, doing no harm. Then, for no apparent reason, a Red-winged Blackbird begins to pester the hawk until it finally decides to fly away. But it doesn't end there; the blackbird follows the hawk to pester it as it flees.
Red-winged Blackbirds aren't the only culprits. Blue Jays sometimes get in on the action as well.
Red-shouldered Hawk and Blue Jay
And then there's those grackles. Sometimes they get into the action as well.
Red-shouldered Hawk and Grackle
Well I said that these birds harass hawks for no apparent reason. The other day I was walking outside on a phone call, and I heard a bunch of commotion--there were Blue Jays in a tree going crazy. I walked over to see the cause for the alarm, and there was a Red-shouldered Hawk perched over a nest. I didn't see what it took, since I saw the hawk from behind, and it flew away from me. I had neither my camera nor my binoculars. But I strongly suspect it made off with at least one of the Blue Jay nestlings. I've seen these hawks flying with baby ducks and even Pileated Woodpecker nestlings. So, I guess if one of these guys is perched near your nest, you have some reason for some concern, and some justification for harassment.