birds & salt lick

I always have a huge salt lick down near the woods for the deer who amble through the property and have been noticing the house and purple finches pecking at it on a daily basis.

Interesting! I never thought about what a bird's salt requirement might be. It's just the house and purple finches, though? No goldfinches or any non-finches?

None of the other birds seem to peck at it, not even the gold finches although the black and red squirrels and chipmunks and resident groundhog seem to enjoy it.