I've built several bird feeders to deter bully birds. One worked with 1-1/4 inch openings, but house sparrows have found it and are monopolizing it. II want to preserve food for junco snowbirds that I've had every winter, but sparrows will likely prevent them now that they found the feeder this year. I'm testing a prototype built with chicken wire, and it does deter the sparrows, but will my beloved juncos still be able to get through the 1" openings?

Testing this prototype. Bully birds and house sparrows have given up. Top will be a chicken wire cut to fit if juncos are successful in getting through.

Chicken wire top, 1-1/4 inch openings on every side.