I have Jackdaws and Rooks constantly visiting my bird feeders, in fact they are rarely out of my garden. A gang of them, 8 jackys and same amount of Rooks. I have tried all sorts of things to keep my seed feeders on their hooks but the Jackdaws are clever and still manage to get at them, lift them off the hooks, the seed spills out and they eat it up. Sick of them. At least I have no Magpies though.