MAGNETIC FIELDS

CAN ANIMALS SENSE YOUR SETS?

Science tells us that many animals can detect magnetic fields, which are emitted by the steel that makes up our traps.

Have you ever had that strange feeling that an animal knew a little more than it should have while avoiding your set? How did it know the trap was there? Why did that beaver swim around the 330 bodygrip? Why did the coyote dig up that foothold trap, even though you were ultra careful about scent control and proper bedding?

There’s one key factor that almost no trappers have given any thought to, and it might just provide an answer to that nagging question of set avoidance: magnetic fields.

Georgia trapper Kirk DeKalb has caught more than 16,000 beavers in his career and helped design and develop a number of trapping inventions and devices, including numerous types of cage traps. Over 23 years of professional trapping, after piles of catches, careful observation and numerous experiments, Kirk began to develop a theory that animals are sensing the magnetic field of certain types of traps, and it’s impacting their willingness to work a set.

It all comes down to these things called cryptochromes. Cryptochromes are a class of flavoproteins found in plants and animals that, among other things, allow certain animals to sense magnetic fields. They are what enables birds to sense the Earth’s magnetic field to orient themselves during migration. Not all animals have cryptochromes, but the ones DeKalb argues can detect trap sets do.

Scientists have found evidence that dog-like carnivores like coyotes, wolves and foxes do have the magnetic-sensing cryptochromes, while cats, like bobcat and lynx, do not. Some rodents do – presumably at least beaver and otter, according to DeKalb’s experience.

The theory is that these animals that have the ability to sense magnetic fields can detect and actively avoid many of our sets. This could be an interesting explanation as to why coyotes, for instance, will notoriously avoid uncovered traps, while bobcats will step on a trap pan in broad daylight with no concern. Magnetic fields.

So if this theory is legit, how do we measure these magnetic fields, and determine which traps are more likely to cause avoidance issues? Well that’s easy. We have smart phones. Almost all phones these days come with a built in magnetometer, which is used to determine orientation. It’s what makes things like the compass app work. You can download an app (most are free) that will use this magnetometer to measure the magnetic field of anything you put the phone next to. So with the magnetometer and the app, you can start measuring magnetic fields of your traps, compare traps and snares, contrast different set scenarios, and start the learning process to determine whether this magnetic field thing really is impacting the effectiveness of your sets.

A few things should be considered when going down the rabbit hole of magnetic measurements. There are a number of factors that can impact an animal’s ability to detect the magnetic field. As DeKalb says in his book, “An Outdoorsman’s Greatest Discovery”, the further north you go the less of an impact the mag- netic field will have on animal behavior. That’s because the background magnetic field is greater as you get closer to magnetic north on the globe, and so changes created by metal objects aren’t as dramatic. Maybe that’s why foxes are more likely to step on bare traps and go through bodygrips in northern areas?

The cycle of the moon affects magnetic fields, and air temperature appears to do so as well. Setting traps underwater essentially eliminates magnetic field detectability.

Traps and sets can be designed to reduce their magnetic field intensity. For instance, Kirk states that power bedding foothold traps with metal spikes reduces their magnetic intensity. Certain types of steel that traps are made of have different magnetic intensity than others. Some cage traps are designed in such a way that the magnetic field inside the cage is lower than it is outside. All of these things can be tested with a simple smartphone, and tested on the ani- mals we trap.

Before hearing about Kirk DeKalb’s discovery and reading his book, I would have thought this whole thing was a joke. Invisible magnetic fields affecting the way animals react at a set? Give me a break! But as I pulled more and more information together, it began to make a bit of sense. While I don’t believe everything laid out in his book, I think this magnetic field thing is absolutely worth looking into more. If it’s legit, understanding how these things work will make us much more effective trappers and give us an edge on the competition.

Click to find Kirk’s book, An Outdoorsman’s Greatest Discovery, on Amazon