My hanging Peanut Feeder (with outer squirrel guard cage) is used by Blue Tits, Great Tits, Coal Tits, Long Tailed but today I saw a House Sparrow HOVERING with wings going flat out to peck a peanut from the feeder it is not built to cling to. Never seen this before but in minutes a Robin was doing the same, indeed they were taking turns.
I've often wondered how far a bird can go on a seed, i.e. is the nutrition worth the effort it takes to get it?