Now I've been beaver trapping my whole life but I can't ever understand why it is that some smart beaver choose to dry fire 330’s rather than leave them alone all together? It’s obvious that they know what a 330 is all about but I highly doubt they can reason enough to want to protect the other beavers in the colony that don’t.

What type of set?
Bait?,Lure?Blind?

Fully submerged blind sets in run or entrance doesn't matter...and no it's not rats.

A human competitor?

Osky

Going over the top and kicking the trigger?

X2

We've got snow and my tracks are the only ones in there so I highly doubt it. I've seen this behavior other times too. Just baffles me as to why and how they do it.

BTW, I put an end to the shenanigans with a snare. Just curious if anyone knows how or why they choose to do this instead of leaving the conibear alone all together. Seems like they are playing with fire unnecessarily

X3

I have caught them by the hind foot in 330's before and attributed it to this. However, this one was able to consistently dry fire a 330 in a bank den with no room above the trap.

Move your trigger over to the side.Make sure your trap is on the bottom,and solidly anchored(trapstand or tee pee).
Beaver move a lot slower in a run than trappers think,and when they encounter anything in their run they will try to clear it.This is why you need it set solid and on bottom.Also,besides solid trap support,the trigger moved over to the side will lessen the chance of them firing the trap with their nose(a miss) before they move thru the trap when grabbing it and trying to move it out of the run.
We have trapped a lot of beaver in winter under ice at the entrance and when we started setting the traps this way the empty fired traps was almost nil.
With traps like belisles you will have beaver occasionally caught by one or both front feet when using an ordinary set up in the entrance run.This indicates the beaver was stationary at the trap trying to clear the run.
Moving the trigger to the side has other advantages in this application also.It allows the beaver to get further into the trap,and when setting 3 or 4 traps together at one entrance it prevents one beaver from firing more than one trap.Also beaver when coming in to the house often carry a stick.With the trigger set to the side,there is less of a chance the stick will hit the trigger.Often with the trigger set to the side you will get the odd beaver with a stick still in his teeth,since he is further into the trap when it fires.

Boco, I'd have to agree with most of what you said. I have to disagree about a miss resulting from a nose fired trap. I believe that any beaver that fires the trap with it's nose is history. In this particular case, I had the triggers twisted together and off to one side. The traps were on an H stands and set fully on the bottom. I too find that this reduces the stick catch and often results in a suitcase hold on the beaver.

I find your theory interesting about catching stationary beavers by the front foot when they are attempting to clear the run. It seems very possible. I personally have never held a beaver by the front foot in a conibear but I don't use Belisles either.

And that's why I run belisles...takes revenge of muskrats firing traps and holds non-cooperative beaver.

Sometimes you grab them right by the tail!

I may have not made myself clear.If a beaver fires a 330 with his nose when moving thru or into the trap it will connect.Not so when he is stationary at the trap and has a hold of it trying to move it.

Great Photo 160user

Took all the beaver on an ADC job years ago.....Except 1, the Big Ole' Female.
Now this was still open water and I had mb750s out, and Bodygrippers... in one section of their waterway there was a sharp bend/ corner the 33o was under the divepole and was blocked on each side...this trap was fired 3 nights in a row.
...I removed some blocking and added a 29" Belisle 660 so the creek was covered. That night I set up a 14' ladder stand to watch with binoculars in the moonlight. This Big female came in Slow just after dark and I could see her coming about 30 yards away she motored up to the trap to within 4 inches - after a few seconds she did an Olympic swimers front flip and set that trap off with her Tail....
...She backed off and slowly swam up to the 660 and performed the same front flip trick and swam away from those fired empty traps. Next day I pulled all the traps for 5 days. I came back with Two Mb750s and chain slide drowners. I got in the water 150 yards downstream and walked only in the water until near that sharp bend. There I made 2 slick spot sets 8 feet apart-wearing bemacs. One set got 4/5 drops of popple bud oil and a peel stick...the other got 4/ or 5 drops of birch oil... I walked the water out of there and had Her the Next day.

....Some beavers Have learned a lot.

I know your issue was different, and in front of a bank lodge...in that case I set with an H stand firm, and like Boco said move the trigger to one side OR in an L shape to one side ...open up the trap.

Good post Boco. Most beaver are trying to clear all the junk out of their runs, because they will be bringing sticks/ food into the house or bank den. Looked at a lot of pulled down snares, with blocking sticks, before I figured out what was happening. Stopped using blocking and just a snare in the run, suspended from a single wire and sharpen your knife. They want their runs clean, not full of sticks, that will later catch on what they bring in. Beaver can be tail caught, like Rob has pictured, by knocking a 330 over in a run or by going over top of it, or by reversing direction quickly and springing the trap with it's tail. Same thing with back leg caught beaver, at a castor mound or sudden rise in water level.

Had 1/2 a beaver tail in my belisle 330 one time. My cable tie off was twisted up like a rubber band on a Balsa Wood Airplane....and Caught him the next day. That’s my only tail story..

Could it be fish that are setting off the conibear?

Mabee an otter .