I have often wondered if mustelids recognise an area as being dangerous and avoid traps in that particular area ? I run a couple of lines in the Canterbury high country using mainly DOC 150s. I have on many occasions moved a trap 20/30m away from where it was and the next check I have caught an animal. Spots that have consistently caught for a year or so and then they just stop catching…, move the trap 20/30m and we are back in business. I have done this enough times (lots of times) that I believe somehow mustelids are very wary in a particular area. One trap that I am thinking of for 2 years was my best catcher in a line of 50 traps and now I guess I have not caught an animal in that trap for 18 months at least, nothing…
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Could the presence or absence of cover between sites be partly responsible?
In the Canterbury high country, siting tunnels close to natural and/or artificial forms of cover ought to be an effective way to increase kill rates, because mustelids will feel safer stopping to interact with your tunnels.
Are some of these tunnels being moved back and forth, or they only being moved to new locations every time?
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I have seen this behaviour with rats. Have a trap in a location for a year and catch nothing. Shift it 5-10m away and you get 6 rats in a month.
I don’t have any insight into why this is the case. The only thing I can think of is that I have shifted rat traps off of vertical trees to trees on a 45 degree angle… Will rats choose a sloping tree to run up rather than a vertical one?
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Hi ww, I have shifted the odd trap back to where it was originally sited [and catching and then it just stopped catching] but now I no longer shift them back as I just dont catch in that spot. It seems impossible that a trap that was catching well for a couple of years can just stop catching.
None of my traps are just a random box stuck out in the open , they are under good cover [matagouri bushes] and on or right alongside game trails.
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I had assumed that your traps would be in sheltered spots along trails, but you didn’t describe the trapping area(s). I was picturing large expanses of tussock on large hills in my mind’s eye (I’ve never been to Canterbury high country).
Moving tunnels regularly, especially from sites that were once productive, should result in a large reduction in interaction rates, because adult mustelids that have encountered your traps before, might experience neophobia when they’ve been moved. Your ability to trap mustelids in tunnels that are re-sited regularly appears to break the rules.
If you don’t already keep records of your trapping, it would be great to find out how your trapping rates differ between tunnels that remain at a site for several years, versus the ones that you re-site regularly. It would also be interesting to find out if there are differences between the sex and age of the kills. For example, do your repositioned tunnels kill more female mustelids than the tunnels that remain in place for several years?
Out of interest, what kinds of lures do you usually use?
Cheers.
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Taking the time to thoroughly scout an existing or new trapping area, examining it through the eyes of predators, is very important. I wasn’t happy with my kill totals back in 2019, so I did a lot of reading about trapping and talked with some experienced locals. I did some scouting, and relocated most of my tunnels, some of them a short distance from their original site (5-10m), and the increase in kills was dramatic.
Presumably, it takes less energy for rats to reach traps when they don’t have to climb vertically, so traps on angled surfaces, should have higher interaction and kill rates. Traps on sloping surfaces should result in a large increase in the trapping rates of brown/Norway rats, especially, because they don’t climb as well as ship rats.
You could run an experiment to test the efficacy of vertical traps vs angled traps. Mount a pair of traps vertically on a trunk a short distance from each other (10cm or so) and put a ramp up to one of the traps. The % of rats that choose to use the ramps would probably be very high.
Cheers.
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Most of my traps are under matagouri bushes right next to “animal highways”.
Sorry I don’t keep records of individual traps but I can see merit in doing so now. I don’t also keep records of the age and sex of the captures
My lures are mostly eggs which I get free. In the business end of the trap I will put a whole egg plus a pierced egg alongside it, I can also add rabbit bits, duck bits [feathers attached] ,pork fat and sheep bones. I will also break an egg inside the trap to encourage stoat and mice into the box. If I am using duck [I have almost an unlimited supply of breasted duck carcasses] I also take a hatchet and cut up a bit of duck carcass around the trap to add a bit of excitement.
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I’m very jealous of your lure supplies, especially the free eggs.
Speaking of eggs, I scatter eggshells (some halves and some smaller bits) near the entrance(s) of my DOC tunnels, which leaves visual lures for a long time. If I have plenty of shells, I’ll put some inside the tunnels, too.
Regarding hens’ eggs as lures, I’ve read several studies that found that they aren’t as effective at trapping female mustelids as males, because their jaws aren’t large enough to puncture the shell. Having an intact egg and a punctured egg inside your tunnels should solve that problem.
I’ve read that putting an egg, real or fake, on top of a layer of feathers is a good lure. You could put 4 or 5 duck feathers on the base of the trap and put 1 or 2 eggs on top of them. Scatter some shells at the entrance, and that’d be pretty hard for mustelids to resist.
A feathers and eggs lure like this would be an attractive lure a lot longer than fresh meat. Rotting meat is known to deter mustelids, which are fussier than rats. If you only used the feather and egg combo in some of your tunnels, year-round, your trapping rates might increase. Using “insurance tunnels” with long-lasting lures, has paid off for me on numerous occasions trapping mustelids. In summer, I have to contend with both the heat and blowflies, which find meat lures in no time.
With the eggs at your disposal, you could try making your own mayo. It’s already one of the best edible trapping lures to use, but you could make a mayo with a way higher egg content than commercial mayo, which only contain about 5% eggs (it’s mainly vegetable oil). When I’ve increased the vinegar content of mayo, predators have found it way more attractive. A mayo with more eggs and more vinegar, could be deadly.
If it isn’t too much trouble, recording your results could pay off, allowing you to fine-tune your trapping. Finding out which tunnels and lures are the most attractive to female stoats and weasels, for example, could make a big difference. Do insurance tunnels make a noticeable difference? What are the best winter lures? Are the mustelids where you trap also fans of vinegar?
I hope that you’re able to solve your tunnel location mysteries before mating season starts.
Cheers.
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Yes I often will smash an egg outside of the trap box entrance.
My favourite/most successful lure would be duck breast feathers placed in the business end of the trap covering the treadle, duck feathers really smell and the target would feel [I think] really confident ploughing into them knowing there is an egg in here somewhere ? The only problem is they get wet and start interfering with the treadle and tripping of the trap.
I also dont like rotten meat and it is a real problem in my 3 high country trap lines during the summer hence using eggs, bones and pork fat. the bones just dry out and the pork fat doesnt rot ?
Adding to the mayo, I will give it a try, thank you.
Recording, I know I should be but… sad face.
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The only thing that I put on my treadles are freshly killed mice, placing them on the farthest edge. In order to grab a mouse, predators have to cross the treadle and stop to grab it. If a mouse is at the rear of the tunnel, some predators can run across the treadle fast enough that it doesn’t fire, and some can leap over it. With female weasels and juvenile mustelids, which are often too light to fire DOC traps, the extra weight of the mouse can make the difference. Note: My DOC 150/200 are set at 80g, which allows me to kill smaller predators.
In my DOC single-set tunnels, I will occasionally make a nest out of some feathers. In order to investigate the nest, predators have to cross the treadle. With feathers on top of treadles, some mustelids will be able to get a good look at them and give them a sniff, without making any contact with the treadle, or they might put just enough pressure on the treadle to fire the trap, resulting in an injury or a dirty kill. If mustelids aren’t hit by the kill-bar, trap wary individuals are the result.
It just occurred to me that there might be a good way to make a stable, removable nest lure by attaching feathers to a piece of plywood using small fencing staples. This would keep the feathers in place when it’s windy, prevent predators from removing them from tunnels as nesting material, and keep the feathers away from the trap. Small and medium feathers would be the easiest ones to use, but large feathers could be cut to size with scissors or secateurs. To make a nest a more effective visual lure, white and/or cream feathers would be the best ones to use. Feathers are smelly enough that there might not actually be a big difference between using lightly coloured ones or pitch-black ones.
In summer, fat can go rancid, but it takes longer than flesh does. I’ve trapped quite a few predators with old fat that I had assumed would no longer be attractive to them. Even though the fat that they smell is rancid, I think that they investigate the tunnels to find out if there’s any good fat left. Last winter, I trapped a feral cat and a brown rat in my Timms traps, both of which were large and healthy. The pork pieces were old and had a pretty thick layer of white mold on them, but there was enough good fat in the middle of the pieces to lure them.
I’ve found cooking pieces of fat to be more effective than using raw pieces. I cut the pieces of fat larger than normal, to make up for the shrinking, and I collect the grease. The cooked fat has a nice, strong smell, and I put drips of the liquid fat inside the tunnels. The fat has a tough outer layer that makes it easier to skewer (I have nail skewers in most of my DOC tunnels), it keeps blowflies away, and it takes mice a lot longer to eat it than soft, raw fat. The greasy surface on the pieces also gives them some water and mold resistance.
I’ve tried the same thing with sausages. There were some Chorizo sausages in the fridge that were on the old side, so I fried them up for my DOC tunnels. The brown rats here were very fond of them. One of the dead rats lured a stoat to its death.
Sausages on the menu: trials target feral cats and stoats - Predator Free NZ Trust
Cheers.
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There’s some great ideas here. Especially securing the feathers for “nest” for the egg. As in the sub alpine winds get so strong I’ve had an egg even blow out of the trap!
In regard to moving traps, yes, if a doc 200 doesn’t catch for 8 months to a year, even if once was a good catcher, I look carefully around for another good site nearby.
One trap in particular when it stops catching for a couple of months, I turn it around. Seems crazy but it always makes a difference, just having the entrance the opposite side. Seems to happen every 6 months with that one. It’s a fantastic stoat catcher.
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I wish I could catch a few bird predators - but all we see at present is empty traps – around 200 checked over about 70 acres in the last few days and not a sign of an animal anywhere – just 5 rats during July.
kjs sent me a message yesterday with an amazing picture of a high-country stoat – he has asked me to post the picture and story for him -
My mate and myself headed up in the high country to check a trap line that I run up there. A couple of weeks ago I had replaced the eggs and other baits that I use in the traps so I was feeling full of expectation that we may have caught something. The 7th trap in and we had a freshly caught weasel. Another 3 traps further on and we had a stoat then 6 more traps and we caught our white stoat. I have caught stoats in winter with plenty of white on them but not with a pure white body like this one. We went on to catch 1 more stoat and 10 rats.
Thanks for sharing that special picture kjs
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Thanks mindie. Sorry folks I am a techno dinosaur.
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