Real life scenario.

2012 Scarce marten sign. Voles about average. Slow trapping. Harvest sample 70% female. 14% YOY (male and female)

Okay food source. Complete recruitment failure.

Two options:

1.Keep killing adult females

2. Stop killing adult females, so they may survive to try again.

And in 2012 that was when they measure marten in C notes so it was a hard choice.

Gulo,
DING! DING! DING!!! I say you win!! You got to the point I've been trying to make!! Carrying capacity is constantly changing, due to an infinite number of variables. Changes in food sources, weather, snow pack, rain, cold, trapping pressure (you, or surrounding trappers), etc.etc.etc. As many variables as possible need to be considered, then an educated decision (best guess) needs to be made as to whether or not to trap a particular line, and how many to harvest. This can be when all the rules of thumb you, and others have put forward, YOY to adult female catch ratios, trying to minimize harvest of females, comes in handy......

Dirt, That is certainly an "odd" sample, if I understand your numbers correctly, it sounds like your population was mostly adult females, with very few adult males, or YOY males? I've never seen a population similar to those %'s. I wonder if your males were relocating, or were just trapped off, due to higher trapping pressure around you?

Also, just because there is a good or even great food source, that doesn't mean marten will be in an area. Habitat, weather, trapping pressure, any number of factors may change a regions population density. Like Gulo said, the carrying capacity is constantly in flux, so just because an area once had marten, and there is currently a good food supply there, it doesn't necessarily mean the marten numbers will come back to what they once were, because other variables may have changed. In many cases, trapping pressure, or over harvest, may be an influence. However, other events like forest fires, and logging are a couple obvious, more drastic examples of other influences in population density/ carrying capacity changes. Think about changes in weather patterns, predator numbers, precipitation levels, amount of sunshine vs. overcast days, etc.etc.etc. to many variables to list, that are going to have some effect on that ecosystem.

I agree with you 100%. Marten like any other animal will be wherever the best source of food is. I saw two extreme examples of this when I was trapping up in the Logans years ago. The outfitter that I worked for had his base camp up at about 4500 feet and the cabins were on my trapline. I would overnight there once in awhile so it was handy for me. I would always catch some marten in that valley, but it was never an outstanding area. The only reason I broke the trail out and trapped the area was because it was usually good wolverine country. One winter I got to the cabins and I couldnt believe it, there were marten TRAILS everywhere. It looked like rabbit trails. The trails were so well used you could walk on them. They were spider webbed out in every direction. It turned out someone had left the lids off the food barrels and the marten had found the gold mine. I had a bunch of traps with me so i made a bunch of sets. Every time I would hear a trap go off in the night I would get up and reset it. By morning I had caught 14 marten. I dont remember the ratio, but I do remember that most were large adults.

The exact same thing happened in that same cabin about 5 years later. I hadnt gotten in there that year but the outfitter went in to haul fuel in March. His cabins were in a shambles and there were marten everywhere. In two nights he shot 12 right inside the cabin. Somehow the story got back to the COs and he was actually charged because the season was closed. they got a search warrant and counted the bullet holes in the logs. think it cost him a $200 fine.

Point is, they will stay if they have food, and they will move if they dont. Anyone remember the caribou that drowned up on the Peel a few years back?? They closed the river to paddlers for a few weeks because they counted 45 grizzly bears on a short stretch of river. Same idea.

Perfect example Dave.

Back to the root of the question. If, indeed, marten are dependent on voles for sustaining decent populations, are there things we can do to maintain that food source? Boco, I believe, talked about old-timers that distributed beaver carcasses far and wide to supplement hungry female marten in the early spring. I have no doubt that this helps (as evidenced by the higher marten numbers in the harvest in SE Alaska following a heavy die-off of deer on the beaches). However, supplemental feeding would be a task too large over a broad area. Thinking about this, I'm of the opinion that habitat maintenance (no monster clear-cuts) is our best bet. Wildfires are a mixed blessing, depending on the size of the burn and the regeneration of forests and their resultant microtine inhabitants. I still think, when populations are depressed (for whatever reasons), keeping the harvest of adult female marten to a minimum will shorten the population recovery period, but, is there some reasonable way to ensure high microtine numbers? Not that I am aware of. I'm all ears...

Jack

HAPPY 2021 TO ALL!!!

Yukon sound like early explorers and finding washed up drown bison on the Red River banks and them shooting Plains grizzly bears off of them and plains wolves. Seems that the English guys did not have the stomachs to digest the soupy meat, or at least the " culture in their guts" as the French paddlers had.
off topic, but it brought back in it the Minnesota connection.
Happy 2021 all out there.

The diseases of the microtones is far from being understood what whips out the system so fast in their populations. Look at what happens with the mouse hanti virus some strains are so deadly while others are just background noise.

Thinking about the recent successful reSEARCH and design of mRNA vaccines, I am wondering if maybe it is possible to create a designer drug that will carry information to create better looking female voles. Might increase the birth rate overall ..... Even one more litter per year or slightly larger, more attractive litters would be helpful.

Same thing happened here about 15 years ago. A remote military cabin at an aircraft practice bombing range. Marten got into the camp and at the food and I believe it was about 12 they got between shooting and traps. Of course the problem was not the marten it was the camp. Guys got a bunch of off the books cash.

I am really interested in how you know a "refugia" area, that you aren't trapping, has a higher or lower population than your line.

Well, you can trust me when I tell you, he KNOWS his area intimately! T4E is not an armchair quarterback, but the real deal. 24/7/365. And the area where he lives, while somewhat remote, and pretty vast, is pretty much his own oyster, and has been for a long time.
Couple that with his dedication, curiosity, IQ, and determination, and you get, well, him.
He lives his area, land and sea, every single day.

martentrapper,

On the average year, for the 6 weeks leading up to marten season, I probably average about 150-250 miles (over the course of those 6 weeks), on foot, through my areas of refugia, prospecting the line and surrounding refugia, while hunting, berry picking, fishing, mushroom gathering, etc. I pay attention to all tracks, track densities through prime travel ways, note the number of dropping and what's in them, etc.. You can actually tell at times, when a food source changes or comes in to high abundance and is currently being utilized , when inspecting the droppings. Dietary make up items, like berries, crab apples, fish, and microtines are often able to be discerned from the dropping, by just looking closely at it. Many microtine bones for example, are often visible....The information is out there, a guy just has to learn how, and have the free time, and energy to go gather it.....

Here are a couple pictures from the fur shed tonight, for you Northof50. Not very good quality, but best I could do, without cutting into the skinning time to much. The flea was about 100X and the mite around 200X.

Sharon, is that hat starting to feel itchy ; ) HA!!

Gulo & Y254,
I essentially agree with you both, in MOST scenarios, the marten will be drawn to the best food resource, might be a very few exceptions though. I don't want to go into to many opposing scenarios, at risk of sounding argumentative. I can think of some though.....

I guess my mind often works in a cross between fisheries management strategies and wildlife. The pre-season scouting and assessment is essentially establishing my very rough AI (abundance index), and my catch rates on the first check will show whether or not I'm meeting my GHL (guideline harvest level). See, I never think in normal terms..... HA!!

Trapped4ever thanks, you can see the problems with identifying mites, depending on what life stage they are. As for fleas most of id work is in the male form and shapes and barbs of it's delivery fool. How to explain around filters of the forum sometimes is tough

If I have no recruitment and little incoming dispersal ( which should be YOY) and the previous years I have been harvesting males to females at 60% to 40% rates, why would I have many males in my trapped population. Much less adult males?

My population after trapping and into summer should be primarily females. After recruiting 50/50 males/ females I will add new males to the population.

My male population tends to be young. If I break into new territory they tend to be old.

Being an opportunistic predator and taking in all the variables that occur as trappers we can only take advantage of any present situation at the time we are harvesting. We all know from experience that trapping marten from one year to the next can produce totally different results.
Taking in an ideal harvest of mainly YOY and few adult females trapping only removes the surplus that would either die or in some cases migrate to better locations.
One thing we have not really commented on is price?
How much of a factor does price play into the harvest?

After the last price surge in 2014 I put a lot more effort into my harvesting effort, the next season I set 100 boxes and on first check caught 4 marten, I did not have to sex them to know I was in trouble and wasting my time chasing after marten.
Time is money and not having many marten I had to switch efforts on the fly.
Now with the present market prices again who can afford the time and cost to really go at?

Just another variable that we don't really have much control over.

Price of the resource has to be factored in with the cost of catching.
Trappers that live on their lines and are more efficient harvesters(less expense to produce)and depend on fur income for part of their livelihood may trap more to make up for a drop in per unit price.
No matter which method of management you use-(the spot price of the pelt in any given cycle should not be allowed to harm the resource through mismanagement) keeping a close watch on your adult female to juvenile ratios will be your best indicator of the health of your population.
That said you need to harvest a number of animals to make that determination.
Trapping later in the season will normally produce more adults as the juveniles disperse or have been harvested,also later in the season,in my area traps in or near the older natural successional forest (optimal denning areas) will produce mostly adult females when trapping later(feb).The traditional method that the Cree use to protect their marten is to stop all trapping marten around the end of December.
Over my years of trapping marten I have seen those years where there are "marten everywhere",right through the harvest season.There will be an abnormally high number of adults in the harvest.This indicates a widespread crash in the food source with a resulting abandonment of home range-marten are on the move en mass. In every case after these scenarios the marten numbers do crash hard in my experience,but usually are on the way back up after a year to some degree.Only once I have seen the populations bleak for two years after a widespread failure of marten main prey(voles).Management decisions at this time are not so clearcut.Some think harvesting heavy at these times is prudent since "they will die of starvation anyway".Others believe the opposite,to try to leave a decent number to help with the recovery.

I keep a close watch on the 5 year logging plans in my area and take note of the winter harvest plans.If there is going to be a harvest of wood in midwinter anywhere , I will re-set existing marten boxes located on the travel routes that I set up to harvest juveniles in the fall.
Quite a few times I have picked up a lot of dispersing adult marten displaced due to logging operations in late winter.They follow the same dispersal routes that the juveniles do when they leave core habitat in the fall.Adult marten displaced in late winter tend not to do well in my opinion so I dont have any qualms about harvesting those marten displaced due to loss of habitat thru logging.

In my area of the province logging has not had a detrimental effect on the overall marten population(it has affected individual traplines,but a lot of trappers here have several traplines) due to the vast area.It has not fragmented the landscape as much as it has further south in Jims area.When the bush is too fragmented by logging, trapped out areas of good habitat are not able to be filled in by dispersing marten leading to less and less harvestable numbers in those areas.

Glad to hear Im not the only one who digs around in poo ! Not often anymore that I run into someone who spends enough time out on the land to notice things like you mentioned. When I was a boy growing up it was certainly more common, but not anymore. I really notice it during hunting season when things get tough. Very few guides really understand the animals they are hunting anymore and seem to just travel around hoping they will stumble into something. Knowing the where, why, and when animals travel, feed, and sleep is the key to consistent success. The same goes for trapping. I've never met you, but I knew years ago just from looking at the pictures you posted that you were indeed the real deal. There are always things none of us understand, or ever will, but if we spend enough time out there and keep our eyes open, we will constantly learn. I remember as a kid I would follow animals tracks just to see where they went and what they did. I learned a lot doing that, and it has helped solve some puzzles over the years.

One thing Ive been thinking about for awhile now is berries. An old trapper in BC told me years ago that blueberries were especially important for marten. He actually used blueberry jam for bait. In the country I trap blueberries and moss berries are more prevalent at the higher elevations. I know marten get them to some extent under the snow, but how important they are I still dont know.

Ok, T4E ....glad I saw your "lousy" photos now instead of just before I go to sleep !

Does make one feel itchy UGH !

Been trying to get through this thread for the past few days...finally made it to the end.

The knowledge shared here has been so valuable, I felt compelled to try and contribute something. Please note that anything I share should be taken within this context: we are limited to taking 25 marten/trapper/year here. So T4E may gain as much experience with marten in a day as I will in an entire season. So take my opinion for what it's worth. That said, I try to learn as much as I can from every catch and every mistake.

Similar to Gibb's experience, timber harvest has an immense affect on marten populations here. The areas I trap have seen far more logging activity in the past 10-15 years than in the past 40-50. We also have relatively high densities of fisher, particularly in young, recently harvested forests. For years I've been trying to tease apart all of the variables that affect marten (aerial predators, fisher, denning habitat loss, loss of overhead cover, snow depth, snow crust formation, food abundance etc etc.)

The research done in northern Maine has indicated that trapping pressure, at its current level, does not affect marten populations. Habitat loss due to timber harvest does. Fisher do. The theory goes that snow depth limits fisher distribution, and the presence of fisher limits marten populations. Obviously there's lots of overlap and varying conditions, no solid line anywhere.

Marten here do not spend much time in the open. Telemetry studies, and observations of tracks, indicate they don't stray far from overhead canopy cover, presumably due to the abundance of hawks and other aerial predators, but I also wonder if fisher influence this as well. Fisher do well in cut-over forests and open country here, although in deep snow without crust they struggle, and you will often find them concentrated in the cedar swamps. Fisher seem to be able to catch and kill marten effectively, but I've been toying with a theory that more complexity on the forest floor and cavity trees may allow marten to better escape from fisher. This might help explain why marten do well in less complex forests in other places (Alaska interior?) that don't have fisher, than they do here.

As far as food goes, our forests produce heavy mast crops every other year, which directly affects catch rates due to food availability. There is probably some level of food limitation in the poor mast years (the odd numbered years lately), but I'm not sure it is as limiting as in latitudes further north, and don't know that it drives populations. If it does, it's probably minor in comparison to overall habitat changes. We have large numbers of moose that die of winter ticks in late winter/early spring, which may provide excess feed for adult females. More study of springtime conditions related to reproductive success would be interesting. That said, every embryo could implant in every female uterus, and every little one could survive.....but if suitable habitat for them to disperse to is limited .......

Gulo's Idaho marten trapping experience was pretty fascinating to me. Although nowhere near as dramatic, I think I have noticed a similar pattern. Three years ago I set up a line, 60 boxes, in an area that had been cut over pretty hard. With the level of harvest I figured it wouldn't be touched for another 10-20 years or so, and I could kind of set it up as 'my' long term marten/fisher line. There were a number of really nice micro-habitats for marten in the area, mostly riparian areas, and buffers of mature forest between clearcuts. Over two years I learned a lot about the area, especially when there was a coating of snow on the ground. In short, I found that there were more fisher than marten in this country (about 50 sq miles) and the majority of my catch consisted of smaller marten, I assume mostly juveniles. Looking back, I'm thinking these were juveniles dispersing from refuge areas, particularly a large block of timber that the landowner hadn't yet punched a road in, and a block of state land.

This season I completely abandoned that area and keyed in on the largest block of mature forest I could find. My catch rate per trap night was more than 4x higher (approximately, have to check notes), and far more larger adult males. Also caught less than half as many fishers. An eye opener. I believe I was looking for mature timber and classic marten habitat correctly, but at the wrong scale. Should have been thinking in the scale of thousands of acres rather than 10 or 20 acres.

I thought about this a lot today as I pulled boxes from about 20 locations I had forgotten to get back to from 3 years ago. It was a frustrating day. About half of the areas I had sets in 3 yrs ago were either clear cut or heavy selective cuts. Several boxes had been completely obliterated, never found them. The little marten habitat that had existed in the area has again been cut in half. And the main 'refuge' area has a new road punched right through the middle of it, and is starting to be harvested. As a French Canadian trapper once commented to me, "Well, marten needs tree". Words of wisdom for sure.

Guys 30 years my senior tell me I should have seen it 30 years ago. Sadly I'll probably have to say the same to my kids, and maybe their kids. Hate to be negative. I'll still get after it every year, but have realized I'll never be able to seriously trap marten without moving to Alaska. Hope it's not too crowded by then!

Thanks for everyone contributing to this thread, I've learned a lot.