Tunnel Traffic: Late Winter Mink Trapping.

I don’t have to tell most of you how the winter has been going. Here in New Hampshire we have received 100+ inches this season thus far, and we aren’t quite out of the woods yet! However while the high snow totals may be giving some of us cabin fever, the critters are still always moving; and while the snow loads break our backs; for trappers, it can also make life a little easier as wildlife sign is highlighted against the white, deep snow.

New England is notorious for unpredictable weather; temperatures can range dramatically from day to day, and as such, the snow tends to have a freeze/thaw effect which creates a crust on the surface. This year’s brutally cold winter allowed for most of the snow accumulation to remain rather fluffy, as opposed to dense and hard-packed. This in turn forced many furbearers to tunnel under the snow rather than on top of the crust for travel.

Last week, I was contacted by a local client who was losing “precious cargo” to mink predation. This is an annual phone call – usually in late February when Old Man Winter shows the extent of his chilly grip, and also in tandem with the mink breeding season. I utilize this property during my fall/winter fur trapping season, and while the muskrats and otter stacked up, the mink were nowhere to be found – a cycle I go through every winter with this property. While in years past I was usually chasing after one offender, this year yielded four different mink, all targeting the property from different sides. They eat well too – last year’s catch yielded a big female about the size of a house cat; nabbed by a 160 Conibear-style trap placed in between the culvert that runs under the private roads within the property.

Upon arrival this year, I was met with a roadmap of sign in the fresh powdery snow as to what was going on. One mink was crossing a busy road just outside the property, and rather than attempt to climb up the snow banks from plowing the private roads through the property, was busting through the banks with intricate tunnels here and there between banks. In typical mink fashion, the nightly attacks were perpetrated through different avenues. Like other members of the weasel family, mink are extremely sporadic and nomadic – making a quick “in and out” control job nearly impossible. Additionally, there is no telling how long they will stick around; they may show up four nights in a row and then not return for four months! When trapping during the regular fur trapping season, bottom edge sets placed in streams and brooks will produce great results in targeting mink if you have the right spot, but when targeting a specific mink in an area where they are determined to get a bite to eat, you’re dealing with a whole new animal. I am a firm believer that if you are new to animal control work, and can successfully take care of a mink issue (especially on land), you can call yourself a “seasoned ADC trapper” by the time you’re done - with plenty of new gray hairs to show for your efforts!

Typical mink tunnel in deep snow. 

Once I arrived at the property I began reading the obvious sign in the snow. I noticed some tunnels were caved in, or very powdery; while other tunnels were smooth with a layer of crusty ice around the inside. This told me that these particular tunnels were heavily used – the body heat from the mink traveling these tunnels regularly caused the formation of ice along the inside of the tunnel. I began removing traps and gear from the truck, and choosing these tunnels as my “target” areas. If this was an “off season” call, I would use cages to relocate the problem mink to a new area; however being in the thick of winter, and the mink trapping season, I opted to utilize lethal traps to harvest fur and glands. After speaking with the landowner, he was aware of at least two different offenders, and the different sized tunnels and tracks at either end of the property would suggest the same. “One of them is a giant monster” he stated. Like I said earlier – the mink in these here parts can give a small Fisher a run for it’s money size wise!

Trapping mink in the snow can be tricky. You want to get your trap in place with as minimal damage to the tunnel and tunnel entrance as possible. The idea is similar to trapping moles in the spring; I opted to install 110 body-gripping traps in the middle of the tunnels, rather than at the entrances; the primary reason for this is to avoid suspicion and refusal by the target animal – by placing the trap in the middle of the runway rather than at the start forces the animal to commit to entering the tunnel. To achieve this, I traced the tunnel through the snow banks and located the entry and exits. In the middle of the snow bank, I dig down until I have reached the tunnel cavity. With both sides of the tunnel cleaned out of snow debris, I line the bottom of the tunnel with hemlock boughs; this is for scent coverage, as well as to ensure that the trap doesn’t freeze in place when installed on the bottom of the tunnel. With the trap in place in the center of the runway, and the trap securely and firmly staked down, I lay more hemlock boughs across the top of the hole I dug, and then pile fresh snow on top of the boughs. The boughs on top are used to help reduce future precipitation from making it’s way into the hole and freezing the trap in place. These boughs also act as a “funnel” to keep the mink traveling the usual runway into the trap.

Above: Note the diagram for installing body-grip traps in mink snow tunnels. 1. Locate the tunnel, and dig a section out of the middle of the tunnel; install a rock or hemlock boughs to avoid freeze-in during warmer days. 2. Install the trap and make the needed staking and stabilizing placements. 3. Cover the top of your hole with more boughs to avoid future precipitation from freezing trap. 4. The final view of the set - note the original tunnel entrance at the bottom of the image.

To mix things up, I opted to experiment with some alternate traps for this job. Tube traps, or “stove-pipe traps”, were designed in the 1980’s for mink trapping. Today, they are primarily used by Wildlife Control Operators for squirrels. The tube trap offers a focal point in an open area covered in snow, with the mink seeing a primary food source in the midst. In wild settings, mink will commonly investigate culverts and flowage pipes looking for frogs, crawfish and the like. The tube trap offers an ideal focal point, playing off the investigative nature of the target animal. The tube traps were placed in easily visible tunnel entrances with the trigger system wrapped in plastic to reduce the possibility of freeze-in. I had no idea what to expect from these traps; for me, it seemed as though the pan tension is too stiff for the light-footed mink, bounding from point A to point B. If they proved to be successful, they would become an invaluable tool in the trapper’s “control tool box”.

Standard unmodified Tube Trap.

Four nights in a row that mink visited the property, and on the fifth day I arrived and set traps. It was another four-five days of waiting, checking empty traps, and hoping I hadn’t missed their sporadic travel window before I received a morning call from the property foreman stating I had a dead mink in one of the 110 traps. “One down, but it’s not the big one we’ve been seeing” the foreman stated. I remade my set, and inspected the other sets dotted throughout the large property. 

First mink caught. (Note the ideal target catch right behind the head.)

Tracks in the snow identified some concerns with my equipment, and a brief chat with the client garnered insight into issues with one of my trap. The client stated he observed a mink run not once, but twice through my tube-style traps without setting them off. Tracks in the snow confirmed this. I now know that if I am going to add these tube traps to my bag of tricks, they will need some serious modification such as night-latched dogs (the bar that releases the trap when the pan is stepped on), and perhaps some kind of modification to the inside of the tube to ensure the mink steps exactly where intended.

Discouraged, and now a little more informed, I went back to the original playbook and stuck to my 110 body-grip traps in the snow banks. It was a day or two later when I had my “monster mink” waiting at one of the tunnel entrances during my daily trap check. Three mink down in little over a week, I left all traps in place to ensure no one else was following suit for an opportunistic meal. While the traps remained empty daily, the foreman called to report that his dog had chased another large mink into a root system on the far backside of the property (these guys REALLY love the free meals at this place!) As the snow began to quickly melt away, I constructed a few more snow tunnel sets and installed a 110 body-gripper within the complex root system of a large tree. The mink droppings around the area suggested this was a regular haunt – and I wondered if this particular mink was going to be an “over-night” grab or one of the many mink that show up and continue moving on like nomadic transients in search of food and temporary female companionship.

Blind set made in tree-root system.

During the writing of this article, I am currently still waiting to see what will be in my traps in the coming days. After years of pursuing mink and understanding every aspect of their biology and habits, I still to this day feel like I sometimes don’t know anything – and am constantly gaining new insight into their behavior.

Bottom line, mixing up presentation, and where and how your traps are presented; whether it is on the trap-line or for your ADC calls, might just be your ticket to increased success! It’s like a chess match, those mink will make their move, and I will in turn adjust accordingly to make mine. Stay tuned to see who in this situation gets the right to call “Checkmate”.

3rd and largest mink removed from the property. Note the tunnel entrance.