Bird feeder and greedy squirrels

The bird feeder was knocked to the ground this morning - too much weight caused the frayed string holding it to fall. After checking the roof flashing above the feeder, I noticed several apparent claw marks, which would seem to indicate that squirrels were somehow trying to divebomb the feeder to get at its contents. One likely succeeded, thus causing the whole thing to collapse to the ground.

I've hoisted it up again, but doubt that the attempts will halt. Perhaps attaching it to the underside of the eaves (and thus out of the way of all but the most acrobatic of squirrels) may be a more appropriate solution. True, I could just remove it completely, but after providing food for birds through the autumn and start of winter, I think that I have a moral obligation to continue feeding them, since it's kind of late for the remaining birds to try and migrate south.