A bird feeder for deterring squirrels and other maurders, the bird feeder having an inner feed container and an outer shroud, the spring mechanism being mounted in a center structure which comprises an outer first member having a hollow interior portion with a second plunger member mounted interiorly of the hollow member, the plunger having an upper stop member and a lower stop member with a spring mounted between the lower stop member and the base, the shroud being connected to an exteriorly extending portion of the plunger member.