Monday, 8 October 2012

Deadfall Dead Weight

Don't Believe the Hype
If fire by friction and making spoons rank highly as bushcraft skills, then making traps, especially the figure four deadfall, is on the top of every survival whittler's list. The figure four deadfall trap has long since been near the bottom of my list of skills to teach as food from furry animals is very low priority, let alone the fact that this particular trap is hard to make, hard to set and for the effort, not sufficiently effective in a general survival context. In this article I'll justify my disenchantment with this ridiculous contraption. I am constantly amazed that it is described as "one of the most important skills", to make one. Personally, I think firecraft, construction of weatherproof shelter, signalling, water treatment and plant identification are somewhat higher.

Let's look at the facts. Deadfall traps are for small to medium sized game. That is to say that they are for catching things like mice, rats and squirrels. So, let's take squirrel as an example, since this is the only animal I've seen a video of one catching. Even Surivorman and Dual Survival, didn't show success with deadfalls, but I did manage to find a video with someone with one under a rock.

Your typical adult grey squirrel might weigh around 600g. With a typical meat yield of around a third for most animals, big and small, that's about 200g. At around 125kcal per 100g, that's 250kcal. This is our baseline with which we make the decision about whether or not it's worth the effort to try to catch our furry friend. If it's going to cost more than 250kcal to catch the blighter, then it's just not worth it. For more information on this principle, see All Things Being Inequal.

Though based on weight, terrain and speed, moderate walking for an average male would cost around 150 kcal per hour. I'm sure you can appreciate that traps have to be some distance from camp, so simply walking to the trap will cost some of the benefit. If the trap is empty, then it'll take another walk, reducing the benefit further. This is why, in a survival situation, we merge all of our walking tasks into one trip. Collecting water, food, firewood, checking signals and traps, as well as those personal breaks are all done in one round early and one late, with one in the middle of the day too, if needs be.

Deadfalls, like counterweights, largely consist of small wooden parts and some heavy weight, be it a rock or a log or some such. Figure fours need a large flat rock and either a hard surface or another flat rock underneath to act as an anvil. You need to have a rock which is heavy enough to kill the prey, but not so big as to turn it into mush, but equally, you don't want it so small that it misses. Though no hard and fast rules apply, I read somewhere that you should use a weight no more than four times that of the prey, so you don't turn it into a smoothie. So that's about 2.5kg for Mr Squirrel.

Granite is around 2.5 tonnes per cubic metre, that's 2.5 grams per cubic cm. So, we need 1000 of those. You typical flat rock might be 5cm thick, so that comes 14cm x 14cm which is ... pathetic. In reality, that's simply going to miss or the trap is going to be so small the little chap won't be able to fit underneath. So, we clearly need something bigger. A more realistic size might about about 40cm x 40cm, which at 5cm thick comes out more like 20kg. Scaled up, this would be like one of us being landed on by a cow, albeit from a small height, but you get the picture.

The chances of finding such an item of reasonable size and shape close to where you want to lay up the trap is rather small, so you're going to have move one, but don't go too far, as that sucker is going to cost you calories to carry. 20kg is roughly what your luggage allowance is on a plane, and rocks don't come with wheels and handles. Best to carry it down hill if you can. Rolling it might work, but flat rocks don't roll that well in my experience. Also, avoid dropping it on your foot.

Having sat by your fire and whittled the components, you're ready to set and bait the trap. Yes, there is a bit of an art to it and yes, it never works first time. Making and setting up a figure four is a bit of an art form and takes some practice. I found a video of me setting one up some time ago. Have a look at this article to it in action. It wasn't a demonstration, more of a fun distraction whilst out with the chaps.

There is, of course, an inherent risk of injury whilst setting any trap and a crushing injury to the hand is not the going to enhance your chances of survival, I assure you. Do ensure that your hands and limbs are not under the weight when setting the trap. I know it seems obvious, but I've seen someone get a nasty bang to the wrist setting up a Paiute deadfall which works on similar principles.

Like any trap, it might not be visited, it might not trigger, it might trigger and the animal escape or, as is the case with these hair trigger types, it might simply go off in a stiff breee. There are many ways in which you can fail to catch something. If these deadfalls were fool proof, they'd have replaced snares, but they've not.

"But the Native Americans use them", I hear some of you say, and this is true. However, other than the fact that Native Americans are well trained and practised, the particular groups, including the Paiute, who use deadfalls inhabit high desert, canyons and mountain ranges, which are not only littered with lovely flat rocks and hard surfaces for them to fall on, but have a high population of rodents to squish. So as you can imagine, with a high volume of prey, high volume of materials and a lot of practice, everything becomes a little more worth it.

At this point we can see then that the trap can be considered specialised to a particular habitat and prey, which is the case with all traps. There is no one stop shop, though there are a few principles, but that's another article. Native Americans employed deadfalls, snares and pits. In the jungles of South America, larger wooden deadfalls were used, presumably to get the weight, but more generally. snares were used. The Inuit historically trapped Arctic Fox using a stone enclosure with a door which closed when the bait was disturbed. A similar trap was used in the Middle East to catch leopard, and the Chinese used nets. In Africa, mice and rats were trapped with funnelled baskets, some of which also had snares. In North Africa, a cage was employed to catch birds alive. Trapping is about knowing what you want to catch and using the resources appropriately, not knowing a single trap and employing it willy nilly.

In order to fully understand my dislike for this trap, you should go ahead and make one. There are various designs, including the one above, and feel free to make your own modifications. The general principle is that the bait end of the horizontal bit of the four goes under the weight and it sufficiently teetering such the the nibbling action of your chosen prey is enough to set it off. Have fun with that.

You should, by now, have a pretty good idea why I don't like the notion that this trap is considered an absolute "must know". Yes, it's good when it's good, but it's not a general, any time, anywhere trapping solution. I believe that unless there is an abundance of prey and plenty of heavy materials where you need them, this trap makes no sense, based on calories alone, let alone the danger in setting and general faff in getting it right.

And finally ... I stumbled across this video recently, and I really do hope that it's a spoof because if these guys really think that having three of the these premade, metal figure four contraptions in your survival kit is a good idea, then they really do need to have a good old think about priorities.

The notion of having a number of premade, specialist traps in your kit is frankly ridiculous. Better to have something more difficult to acquire in the wild, like a better knife, a sat phone or even ... some food. You can get compact emergency rations that provide around 500 kcal per 100g, which is the same as two squirrels. There would be less faff, and more time to carve your figure fours from wood, should they deemed an appropriate trap for you environment and chosen prey.

Look out for future articles on priorities, equipment and trapping. Take a look back at Things in Tins for more information on the sort of equipment that belongs in survival kits.

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