The Shell Game
One of the lesser-known ways to attract birds is by putting out eggshells. Female birds, drained of calcium by egg-laying, eagerly consume them. I have had eastern bluebirds, blue-gray gnatcatchers, northern (Baltimore) orioles, scarlet tanagers, eastern kingbirds, and tree swallows, as well as barn swallows, come to the eggshells.
I save and rinse our eggshells, then bake them lightly on a cookie sheet at 250 degrees until dry, but not brown. This sterilizes them and makes them brittle. You can crumble them into bite-sized bits and spread them on a patch of bare ground, a rock, a platform feeder, or your deck railing. You may find they’re so popular, you’ll need to go to your favorite diner to beg for more!