Two birds in one.
I came across a used Droll Yankee brand 'Whipper' bird feeder today and so far it has stood up admirably to one squirrel attack; it's basically just a rather large diameter tube with collapsing perches that will not stand up to a squirrel's weight. I give the little beggars about 6 weeks before one finds a way to crack it while the others watch, but we'll see. I got it used because it was an 'evaluation sample' being studied by a large retailer of such things, otherwise the Canadian price might discourage a birder even more than the squirrels. Another Droll Yankee device is the 'Spinner,' the perch assembly of which spins around under weight, forcing the marauding SQ to bail off. Both the Whipper and the Spinner are seen in the video below, I'm wondering if anyone has evaluated either (but esp. the Whipper- the one I own is returnable within a reasonable time). Or any similar brand of course.