I want to do some pre-baiting for fishers this year. I am trying to come up with a way to pre-bait and keep the possums, coons and foxes from stealing the bait. Any ideas out there. I will be most likely be making cubby, hollow log set.

I've always baited with beaver or muskrat carcasses but wait for colder Temps and preferably snow. If fisher are in area they will eventually find it. Be aware of sight exposed bait laws when setting.

Put the bait on a "running pole" with a body grip in front. Branches over the bait and a loud call lure. A bird wing for an attractor. If it's on or near the ground, your asking for problems. Johnny Thorpe has a few video's of how he did it. Try his way, it should work well for you. I doubt you will catch any of your problems animals with the bait and trap 3-4 feet off the ground.

PA regulations won't allow most of what you're saying here

To the OP, the only way to keep the unwanted critters away is to hope for cold temperatures so they hole up during the Fisher season.
We can use a 160 in a cubby for Fisher but it has to be recessed 7" into the box

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I'll bet you can pre-bait on a running pole. That does not mean that your traps need to be set in an illegal manner. All you need to do is to get the fisher coming to the location. In fact, it may be a better way to avoid non-target catches if you don't have your traps directly at the pre-bait location.

I have almost no experience with fisher (I've only caught one in a marten trap). but, I bet they respond to pre-baiting very well, like marten.

Never found a need to pre bait for fisher.They are not hard to catch.

This works for me. Hang a large bait. When the fishers show up, remove bait and make a simple set (I use dirt holes) at the location. Usually have the fisher the first night,

I can catch them pretty easily in dirt holes….generous application of Gusto lure. If I tried to prebait them here in my neck of Pa, I’d just end up feeding a bear.

Same here. Pre-baiting only works when the bears are denned up. Sometimes these show up.

Great Picture

Really....what a waste of time and bait.

Just put sets out ...when it's go time

prebait works good for me, when there's snow on the ground or cold, for both bobcat and fishers

I'll half agree. IMO, pre-baiting allows me to catch them faster. But only when the bears are denned. It's fun to have days like this when you only have one week to trap.

When you get 6 days to catch one ...right after Gut piles were everywhere a short while ago they are tough to get ^^^^