Finally something I can weigh in on (lurker here for months,,lol)
Fishers are pound for pound the nastiest predator in WI,,,the numbers have thinned here in the last 5 years, yes SSS hit the area Vilas/Oneida Cty
That said I still saw a few in the last year and they are my biggest fear now that I have a flock of layers and plan to pasture meat birds this summer.
They hunt and eat 24/7 and cover a large range. These critters will kill and eat cats, dogs, ducks, geese, chickens, corn, anything that fits the menu or the appetite. I've seen shed walls ripped open to get at a friends baby goats, sad day indeed.
IF you think you have one around, double check the coop, use extra heavy fencing/wire anywhere you even think there is a possible entry point, and, keep a loaded gun handy at all times at your backdoor. Most have been shot at b4 and will clear out even if you miss.
I deal with an abundance of coons (3 trapped in the last 2 weeks already), fox, coyotes, weasels, eagles, hawks, name it I have it,,,but the fishers are my biggest worry no doubt,,,,good luck
Oh yes, this thing was nasty and big for being in the weasel family. We've been on the look out for it but it doesnt seem to show itself when we happen to be looking for it. I guess I'll have to turn the coop into Fort Knox lol.
FT - yeah I meant fisher lol its called alot of different names.

Thanks for the info everyone.