I watched a YouTube video of a beaver colony trap built from stock panels with 2x4 squares and swinging doors like a muskrat colony. I picked up a 4'x12' panel yesterday and knocked out a couple today. A 12' panel will build a 12x12 and a 12x16 colony. Welders, rest assured I kept an eye on the galvanized fumes and used the light breeze to my advantage so I wasn't breathing it in. I can see these working well in channels below a dam where they have some speed and current behind them. I welcome your thoughts.

I was thinking of building some too but I was thinking of bending them instead of cutting and welding.i have zero experience if that would work or the factory welds would maybe not hold up when bending.

Do you think four feet is long enough for the doors to work? Do the doors look strong enough with out added rods the full length off them?

I tried bending one with my brake. It will do a little over 4’. That was too much for the brake. Just too much to bend with the brake without more leverage and a more solid bench. I don’t think the factory welds would hold up to a brake that was strong enough to make a sharp 90 degree bend.

Once the sides are welded up, the cage is pretty rigid. And when the panels are cut down to fit inside they are pretty stiff. I doubt any beaver are going to bend them. They might find a way to manipulate the door up because they are just gravity doors. I’d be leery of making the doors any heavier. Any heavier and a beaver or otter might not push through. As to the length I can’t say. A beaver could definitely get in one. Not sure about multiples like a rat colony but I’m sure one can. Even a big beaver.

I’m hoping F&G will call me this summer with a beaver complaint to test them out. Hopefully I’ll get a chance this next season to put them to work for a test.

They work great in culverts if they're traveling through them instead of trying to plug them up.

I have found that you need to stake the things if you put them in a run, especially coming out of a lodge. The beaver will relocate your colony trap. NOT fun when this happens under the ice.

Yeah, I figured on staking them or cabling them to something immovable.

Old thread on colony traps for beaver

https://trapperman.com/forum/ubbthreads.php/topics/3272458/2

Buddy jammed one under the ice just to try. Don’t see why not eh?
Towards the end of the vid…..

You guys work way too hard!!!!!! LOL....................... the (lazy) mike

Colony or funnel traps not practical for beaver.By the time you make them big enough to catch 3 or 4 beaver at a time in the run you cant lift them up when full.
Better off to gang set 330s if you want multiple catches per check.

Unless you’re trapping in a state that only allows non gripping traps. No foot holds, body grips or snares.

My whole reason for building colony traps, both muskrat and beaver, is to be able to maybe salvage a little of my season next year. I can use foot holds, snares and body grips in Idaho but neighboring Washington does not allow them.

And to further explain why I’d consider trapping in Washington rather than just going to other areas of Idaho, here’s why.

I am my wife’s 24/7 caregiver. I can take her with me land trapping in the side by side but cannot safely take her in a boat or canoe to rat/beaver trap and there is not a lot of either close locally. And anything accessible by vehicle is heavily accessed by steel headers. However I have family in Washington near my old trapping areas and could have my wife stay with them while I run a line there. That way I’d be with my wife every evening and night, the hardest time for her and for a caregiver, but still get a little trapping in.

I know that sounds selfish on my part and perhaps it is. But until you are caring for someone 24/7 with both severe dementia and acute aphasia, you cannot know how absolutely exhausting it is. To get a little break helps to get one’s mind off things, if just for a few hours. And it never is really a break because you’re always concerned for them and whoever is caring for them. Even when you get a break you never get to fully relax and let go.

So you mean a cage trap to catch a single animal.
A colony trap is a cage trap designed to ,make repeating catches of multiple animals.Great for rats etc but impractial for beaver because of their size and weight.