Three years ago it was almost warfare between me and the resident squirrel; it kept taking the roof off the birdfeeder and either eating or scattering all the seeds. Eventually I repurposed the old feeder as a "squirrel feeder" and purchased a new squirrel-proof feeder for the birds.
That feeder didn't handle the weather here very well, so this year I purchased a new feeder like the first one, with one exception - even I have trouble keeping the roof off, even just for the time to put more seed in. We also seem to have a new generation of squirrels; this one seems to be perfecting an acrobatic move of hanging on to the roof with the back feet while scooping up seeds with the front feet.
This seems to be no more bothersome to the songbirds than the starlings and mourning doves are; we'll see if this becomes the new normal.