Vintage sterling silver screw on bird earrings

Unique vintage sterling silver screw-on bird earrings. They could use a little polishing or TLC but also have a classic vintage vibe as is. Some type of enamel or varnish on the front remains on the tails. Super lightweight. Stamped “ster” on the inside of each tail. They were part of a collection of jewelry I inherited and I believe they were purchased at a southwestern jewelry store in the 1950s or 1960s.