You guys up north that have good populations of both mink and weasels, is it common to catch mink in boxes designed for weasels with the hole for weasel entry ?

I don’t target ermine much, but buddy gets lots of boxes out. He’s never had a mink with a small enough head to fit in the hole.

No mink in weasel boxes. I have better luck in boxes that the end is wide open. I use coni- pans on 110' s or 120's and have caught them that way. I have even caught mink in coon boxes with 220's with coni-pans.

I have plenty of both along the shore of my lake. It’s where they both live. Ermine especially seem to stick to the cattails in the winter. I use #1 LS traps set directly under a 1-1/4” hole in the box and never catch mink. Fisher can reach in and scramble up the area a bit but eventually pull out. Tie the box off to something

Using a box with a 1 1/4 inch hole as described I can't ever recall catching a mink. But I caught a marten in one once.

And don't leave the boxes in the back of your truck when you pull them with the traps still set inside. I did that once and the next morning had two housecats dragging boxes around the yard.

no mink in weasel boxes, but LOTS of weasel in mink boxes!

This says it all ! If you want both use a mink size hole

We don't have a size limit in PA so I made the holes 2 in diameter.