Bird Salt Feeders
I built this from plans in my imagination. It is pressure-treated lumber and made especially for Purple Finches, which use it constantly. I also saw a Chipmunk sampling it. The container is a pint Mason Jar.
This is a later design using a dessert cup
This is my latest design using a Goblet with the pedestal removed. The resulting stem is stuck into an angled hole in the rear board. This design has pretty well eliminated the problem of wind-blown rain getting into the Goblet.
No matter what the design, Purple Finches will love it.