I've seen Red-tailed Hawks take squirrels and full grown rabbits since I was a kid growing up in a rural farming area. I once saw a mature Red-tailed Hawk with a rabbit in its talons on the side of a road while leaving the Allentown, PA airport. And another time I saw one fly overhead with a snake in its talons.
Bob
Red-tails are skilled at using surburban lawns and traffic.
I have seen two take squirrels here in Massachusetts.
Both times, it was a red-tail diving almost straight down,
turning in front of a moving car, and surprising a squirrel on a lawn.
One time it was my car "setting the pick", in the town center.
Just like red lightning...across my grille, between two parked cars,
and straight across the unwitting squirrel. Given the speed,
I think they could take anything squirrel or pidgeon-sized by surprise.
If they are watching critters from a high limb, they are searching
for that perfect opportunity. Even a jogger can be the distraction
they are looking for. Their population is really booming now.
Foxes hit rabbits here, but I can see how red-tails would fill the role
when foxes are not there.