Trapping: Otter Trapping

By Hal Sullivan

River otter


I was slogging through a relatively featureless marsh, at times in real danger of getting myself stuck in boot-sucking muck. I might have turned back, but out there, another 75 yards, I had a trap to check. I had found an old abandoned beaver run, left over from when the beavers had denuded the lowland. The run had filled in over the years and was now only a foot wide and about that deep. I had set a 280 magnum bodygrip in the run, hanging below a stick I had run through the raised spring eyes and then simply laid across the top of the narrow run. I had stabilized the trap with a few more sticks brought along for that very purpose.

It was a pain to slog out there and check a trap in the middle of nowhere. But I had caught two otters in the set, back when otter pelts were averaging $150 each.

Like so many other folks, my otter trapping grew out of being a beaver trapper. Otters and beavers go together like ice cream and cake. In fact, beavers actually create good otter habitat. You can thank expanding beaver populations for expanding otter populations. It’s hard to trap beavers and not catch the occasional otter, if there are any otters around. My first attempts at targeting otters consisted of simply leaving beaver traps in place after I’d taken most of the beavers, until I caught an otter or two.

If I had but one trap to set for otter, I’d probably still set it below the spillway of a beaver dam, because this is the main travelway through the area, used by beavers and otters alike. Of course, I have more than one trap to set, and I often cover that spillway with two traps, maybe a bodygrip down below and a foothold up on the dam. The upper trap may catch an otter, but its primary purpose is to take out the beavers, so the bodygrip will be waiting when an otter does come along.

Yet otters also take pathways the beavers don’t. When I began setting these secondary routes, began to actively seek them out, my otter catch doubled. And the more I learned about setting up such places, the more otters I caught.

It started with recognizing that while otters may be caught in beaver sets, otters are not beavers, and there are behavioral as well as anatomical differences. Otters are well adapted to life in the water. But not to the same extent as beavers. While otters may be most graceful in the water, they are also quick and agile up on the bank. They also occupy a markedly different niche in the food chain. Unlike beavers, otters are meat eaters, and they don’t hesitate to leave the water to pursue prey on dry land. They surely don’t mind scampering through a few inches of water to snatch a fat frog.

A beaver, on the other hand, wants to swim everywhere it goes. Yes, beavers do leave the water to cut trees, but they are awkward and I suspect uncomfortable doing so. Otter traffic is not as tightly restricted to the main waterway, and otters are not creatures of habit to the same degree as the more sedentary beavers.

Given these differences, it only makes sense that there are more otter trails through the typical wetland. An otter roams a wider territory and may take a different path the next time it passes through.

Let’s say preliminary scouting indicates that otters are using the beaver crossing on the dam and also two pretty much otter-only side trails. At first glance, it might seem like you have a one in three chance of catching a passing otter with a trap set in any of these three locations.

But that’s not quite true because otters do tend to favor the main pathway. More likely you have about a 50-percent chance of catching the critter in the spillway, which leaves a 25 percent chance of catching it in either of the two side trails.

This is why, if I only had one trap, I’d set it in the spillway. That’s the best bet. But when otters were high dollar, I bought more than enough otter traps to cover some other bets, too. And when I started setting traps in the secondary trails, I learned a lot about otter travel patterns.

Yes, the main crossover was still the main producer. But about half the time, when that trap was empty, one of the side-trail traps held an otter.

It is pretty much conventional wisdom among trappers that an otter takes two or three weeks to cover a vast territory. However, I don’t think that’s necessarily the case. If you only set in the spillway, and that trap catches an otter two or three weeks later, it might seem like the otter took that long to come back around.

More likely, though, the otter came through more than once during those two or three weeks, only on different routes. And while I have no way to prove it, what I have seen since I started setting up the lesser trails makes me think there are otters that never do take the main trail.

By setting multiple traps, I also realized and soon cashed in on another otter trait. Otters travel in groups, but they also hunt as they travel, and to do so effectively, they must spread out, taking different trails rather than all working the exact same area.

Quite often, I catch doubles and even triples by setting several traps across the beaver flowage.

Several smaller otter trails may even cross over the same beaver dam, because the group splits up and individuals cross in different places. Sometimes you have to look hard for telltale claw marks, but when you find them, you find a place to set for otters in addition to the spillway. The first trapper I heard describe this, many years ago, was George Wacha, from Alabama.

Another completely different type of secondary route can also be a big producer. I call these the back roads, for lack of a better term. I often locate these by studying topographic maps. Today, you can view everything from satellite photography to three-dimensional maps for free on the internet, but I’m old school enough to still like the USGS printed “topos” that I can spread out on the kitchen table. When I sit down with such a map, I gain a bird’s eye view of the whole territory, and things I may have been missing on the ground become apparent.

Pay attention to the elevation marks on a topo map and note where small watersheds come together, like the fingers on a hand. Now look for another “hand,” and then a place where a finger from the first hand lines up with a finger from the second hand. Go there on foot and look for any sort of water route connection. It may be as little as a roadside ditch, but you can bet the local otters know about it.

Other back roads can be a mile or more long. On my Southern trapline, I see this in drainage canals that cut across oxbows in the river. Traveling otters run these canals to shortcut the oxbows, and they can be good set locations because they get a lot of otter traffic.

Another place where you may find otter trails is where two prime pieces of wetland habitat come close together. I trap one such place where a creek parallels a lake. The creek provides a natural travelway, and the shallow lake is teeming with small fish, crustaceans, and amphibians, a veritable otter smorgasbord.

Truth is, I could run out of traps setting every little trail that crosses between that creek and lake, so I don’t try to cover ’em all. Where to draw the line with multiple sets is always a judgement call, but experience has taught me that the second or third choice often produces when the first choice doesn’t.

I’ve also caught otters in bobcat and coyote sets far from any obvious water. However, I don’t want to lead anyone too far astray when it comes to where otters may be trapped. If you set for otters in the back forty, you are asking for disappointment. Otters do prefer water. They feel safer in it, no matter how little. Like I said, I’ve caught otters in ditches I could step across.

In addition to the map study, I find otter trails by looking for them, usually starting in the area immediately around a beaver flowage or other obvious habitat. The abandoned beaver run I described at the beginning of this story was not visible from the dam nor from the road. I waded out into the marsh and found it.

With otter prices ticking back up a bit, I’ve been asked to give more otter trapping demonstrations at state trapper meets. In states that have just instituted an otter season and only allow a limited season take, I generally advise folks to just stick with their beaver trapping and save those limited tags for the otters that come as incidental catches.

But where otter populations and season limits have expanded, locating and putting a few extra traps in the secondary trails may increase, perhaps even double, the catch.

A friend, who along with his wife traps a lot of beavers in what is also good otter country, asked if I knew any secret for catching more otters. Well, yes I did. I told him to make more otter sets.