trapped4ever -

Many thanks for weighing in on this. I figured you were out among the marten tending your lines rather than sitting in front of a computer monitor pontificating like I'm doing. From earlier discussions we've had I well know that you're a critical thinker and often times well "outside the box" (which is extremely valuable and productive).

Back to Rick's initial question (so I don't feel too bad about hijacking his thread). In my opinion, some of the other comments regarding your impressions of high numbers of marten, followed by seemingly low numbers (once the harvest season rolls around) is not too uncommon, and those speculations on the reasons for such observations may well be correct. The "fall shuffle", in which 5-6-month-old marten are heavily dispersing, may be a reasonable explanation for the differences you're seeing. On the other hand, those long-term absences that were mentioned in Labrador don't sound to me like a food or overharvest problem, especially if they went on for decades. There's not really much known about diseases in marten. Avian influenza (H5N1) and tularemia have both been seen in stone marten in Europe. Sylvatic plague and canine distemper, too, are mentioned in the literature as possible population-wide factors which may periodically affect marten. Hearing about the corona virus outbreaks in ranched mink leads me to think that it could also be a potentiall factor in marten population decline. Parasites, too, are not off the table as far as affecting marten. I've done quite a bit of work on the stomach roundworm, Soboliphyme baturini, and it can become quite prevalent in marten. However, when I looked at marten weights versus the parasite loads that they had in their stomachs (sometimes stomachs full of parasites with over 100 individuals), I got the impression that the parasites were not effectively "killing" the marten and thus causing population declines. Thus, while I surmise that diseases and/or parasites could be responsible for marten declines, I have no real data and can't point you to any good literature. It's simply a PIOMA speculation.

Thanks to all for the stimulating (to me anyway) discussion. I'm particularly intrigued over the "soils" theory.

Jack

I agree 100% about the statement of traps per night per length of duration, I believe in the 3 checks max and out method of harvesting.
My limiting factor in my area is commercial logging/ clear cuts. Sadly most of my marten line has been clear cut to the point the habitant has become the limiting factor to the population.
Some good information below
https://en.wikipedia.org/wiki/American_marten

I have seen and trapped marten with huge population swings from one season to the next. Same effort same amount of traps totally different results one year to the next over a 40 year span.

Gibb your latest youtube clip sure shows the logging practices that has effected your harvest on your one line. Maybe post a link for others to watch.

They clear cut in front of my camp in 1980 not a tree left standing on either side of the road for a thousand feet. The only trees left were either for the lake/river reserves or the small creeks, it took 33 years before I caught a marten there again. When I first started in that area the average age of the forest would have been 100 years plus up too maybe 175 years for the swamps, fast forward to today and the average age of the forest would be 40 years to 2 years, with very small fragmented of old growth reserves. Talking 400 feet to 100 feet strips around lakes and streams. My marten population crashed around 2004 and has never really recovered. They would cut the high country in the summer and all the swamps in the winter. It took 20 plus years to reach a tipping point for which the marten could not recover. I started catching fisher around 1987 and can probably catch as many fisher as marten now. I am talking just my 108 square miles which is very flat, all the trap lines around have had the same type of impact.
Nice roads but no marten.

Thanks T4E ! Lots to think about !

Attrition: From the things I have read over the years there seems to be a consensus that the average marten litter is reduced to about 2.2 kits surviving to the point of dispersal. That is just barely above replacement rate. I think that reinforces your point about duration of sets in one location.

Just based on the tooth aging that Gulo did from my line, I have to conclude that marten, in a trapped population, do not grow to old age. Out of several hundred individuals, there is only one male that was 14 years old. He was clearly an anomaly as no others even came close.

If I recall correctly there were no females greater than 4 y/o which leads me to believe that pregnancy is a real drain on them. That may not be borne out in data from and UNtrapped population.

The other noticeable trend is that the overall age of trapped critters declines over time, as long as all other environmental conditions remain equal. That would cause me to ask if trapping might be beneficial to the overall population. Is it possible that marten are capable of compensatory reproduction or has the trapper just encountered more YOY as they are dispersing ?

Another question is, what is the sex structure of all the litters born in an area ? Does it change ? I think I recall reading that male kits were slightly more prevalent than females. Perhaps it was a 1:1.1 female/male ratio. Are young males more susceptible to accidental death just because they may be/are more aggressive ? Could that control the make up of the litter ?

Always more questions than answers

Hey White, on that 14 year old Marten, did you notice anything that would make you believe he was that old when you caught him? Or did he look the same as say a 4 year old?
Ex; worn teeth, body size (big or small), skeletal deformity etc.

It was a long time ago but as I recall there was nothing out of the ordinary when looking at him.

white17 - You didn't notice worn, rounded teeth and severe discoloration on the canines and incisors?

No massive "apple-head" from the masseters?

So winter rain in the interior seems detrimental to marten relying to some degree on subnivean shelter while rain in SE AK seems less so perhaps given the shelter of the forest canopy?

I MIGHT have but........it was over 20 years ago. The head may have impressed me when I started trying to stretch his mouth over it. But I don't remember well enough.

I am pretty sure he must have been a critter who migrated into the area from a large untrapped reservoir.


The individual animal I remember best was a marten caught in my conventional pole set. Caught by the left front.

He was unremarkable at the time I removed him from the trap. Frozen in the typical "strap-hanger" pose.

When I went to skin him I saw he only had the left front. No leg at all on the right. I figured there would be a scar on the skin side. NOPE !

Nothing. Not even a scapula. Birth defect for sure. But he was well furred and even had a little xiphoid fat.

First thing I do when I pick up a male marten in a trap is feel for the "groove" on the top of the head.

11-YEAR-OLD MALE. Central interior Alaska. Sorry, not the best photo.

Ken, the area my daughter traps is pretty much black spruce forest right up to 4500 feet although the trees do get smaller and more dispersed as you go up.

Trapped4ever brought up a good point about the rain. We've all seen his pictures, and it is wet down there, but he gets good numbers despite that. I would venture a guess that his marten probably dont rely on voles like the interior populations seem to. Low snowpack, and wet weather does seem to effect the voles though. Which would in turn effect marten numbers.

I think you bring up a valid point Yukon. The root voles (Microtus oeconomus) are undoubtedly an important food source, and in some places in SE Alaska, the red-backs (Myodes rutilus) and the long-tailed voles (Microtus longicaudus) can be important. However, there are major islands in SE that don't have long-tailed or red-backed voles, and deer mice (Peromyscus) become an important food source. I remember in '02 or '03 a biologist tried to shut down the marten season because of a failure in the long-tailed vole population, and he wanted this closure even on two major islands that didn't even have long-tails, and the marten population was just fine. It appears that the deer mice are not negatively influenced by the high levels of precipitation like the voles. Even in the interior, however, I think that rain is okay for the voles, unless it is sufficient to negate the insulative value of the snow, and it is followed by severe cold. Then, it seems, vole populations are hosed.

Again, T4E could probably shed light on the role of voles in the diet of SE marten.

Jack

On the prairies the deer mice Peromyscus do not travel when the temps fall below -10*c. They go into a sleep period much like hibernationor tubor till it get to zero for a few days. Their denning areas seem to be cavities in trees, so you need some root rot in the jack pine trees to start these cavities ( Armillaria or Annosum root rot ?)

Maybe 10 years ago, I examined stomach contents of all the marten I took, (did it for 2 years, actually).
At that time, I was trapping a valley that was about 2-1/2 miles long, and went from sea level to about 800'. A small stream that had no fish, (a 50' vertical waterfall is about 200 yards from the sea), so not even an odd lost salmon.
I am a conibear guy, so whatever is in the stomach at capture is there at autopsy. Every single marten had a gut full of small, thin whitish worms. A clump of fur here and there, but the worms were in all stomachs, some with dozens.
I forget the name of the worm, but I sent a picture to Ken, who identified them right off. Some research showed that fish is the vector, so I have to assume that at some point the marten made the 3 mile migration to the nearest salmon stream. ALL of them, and foraged on fish

viking -

I'm assuming that this is the stomach parasite you're referring to. Soboliphyme baturini. Very common in Alaskan marten. Females on the left, males on the right. As far as I can tell, even with extremely heavy infestations, the worms do not constitute a significant mortality factor.



Jack

Yep, that's them. Lovely beasts.

Such great educational info , everyone....love learning these things. Thank you all. And thank you T4E , we all appreciate your input very much and your time to share your decades of experience . Everyone appreciates you and values your input.

N50, no one has ever mentioned the time of year from the conifer ends on that picture -great observation ! Thanks Mad Mike, and Scooter, love that taxi mount ! Especially like the top marten on the axe handle. What a perfect setting idea !

Please carry on, I am really enjoying this subject .....worms.....maybe not

Oh boy, I can tell I'm never going to be able to keep up with input on this thread. Just got off the line, and currently trying to thaw out/ warm up. 3 buckets of marten to skin tonight.......
Rain alone isn't much of an issue, in my estimation. It's when it comes in conjunction with other issues (snow depth, lack of snow, rapid cold snap afterward) etc. that it can create trouble for marten and prey species. Vole tunnels get saturated, and freeze solid = bad news for the voles!

I've mentioned in past threads on here, and both Y254 and Oh Snap mentioned similar observations, of what I refer to as "elevational density", my own made up term. At times, marten will move up or down slope, due to weather changes, snow, rain, wind, temperature inversions, seasonal dietary changes, etc. So as you are trying to manage your line, these smaller "migrations" up or down slope, can make it appear there are more, or less marten in the area, than there actually are. In SE especially, I always theorized more marten travel up in the higher elevations, when snow is falling up there, that is coming down as rain at sea level. As winter progresses, and snow line reaches the beaches, more marten seem to show up in the lower elevations. There are always exceptions to every rule. As W17 said, and I say the same thing, the more I "discover" the more questions these newer discoveries raise! I never get ahead on the questions, as the answers seem few and far between, in comparison. Same thing with fisheries, for me, each observation just leads to more questions.....

Like Alaska Viking mentioned earlier, in all regions of the state I've trapped, there seems to be suitable habitat areas, that for no obvious reason, are almost devoid of marten. The strange thing being, not far away, in what appears to be very similar habitat, there can be an abundance of marten. Like others also mentioned, many times I've relocated poor production sets, a matter of 100 yards or less, and had them produce well ever since. I've also had unproductive sets, that haven't produced much for several seasons, suddenly switch gears, and produce well for years??? What changed? Marten traveling a new route?? A few more oddball comments, regarding male/ female kit ratios. I've wondered the same thing as W17, and have always wondered if the males and females may key in on different prey species, during times of abundance, such as males targeting the larger voles, and females targeting Keen's Deer mice and such. I've also always theorized, and observed what I assume to be sibling YOY marten travelling together. I don't know for sure that these are always siblings, they could just be unrelated YOY marten that are travelling/ hunting/ hanging out together.

At some point, I'll try and dig out some of my information from the studies I was involved in here 25+ years ago. Lots of age (cementum analysis), recorded dispersal distances, seasonal diet change, various % of dietary make up for different food sources, etc

A couple other things here. Many times, on the SE islands, I've seen marten up in the alpine, well above tree line, and many seem to be hunting ptarmigan, and raiding ptarmigan nests for eggs/ chicks.

The voles in SE tend to be pretty prolific, at times, and the tidal grass flats in the heads of bays will be criss-crossed with tunnels/ runs, during high abundance years. I've watched many (mainly male) marten out on open grass flats, in Spring, actively "mousing", pouncing up, and coming down like foxes do, while catching these voles. When higher tides hit, these voles will get flooded out of their tunnels, and be swimming all over the flats. While waterfowl hunting in the Fall, when the big Fall tides hit, I've seen dozens and dozens, swimming for higher ground, looking just like a little muskrat. Rain, moisture, tidal inundation, alone don't seem to cause them much harm, I think it's probably much harder on them, when there is a rain, and then long term severe cold follows. Either forming an impenetrable crust, freezing tunnels/ runs solid, encapsulating their food supply in ice, etc......???

Here is a participatory activity for everyone trapping at least moderate numbers of marten. I don't want to tell you my own long term observations, so as not to skew your own perception/ interpretation. Simply keep track of your male/ female catch ratio, during the different lunar phases, throughout the course of the next season or two. I used to hang a calendar, with the moon phases printed on it, in the fur shed, next to my skinning area, then record the number of males/ females, YOY/ adult, etc, on the calendar, while skinning that night. After a while, it seemed certain patterns emerged.......

Another thing no one has mentioned yet, what role do larger kills (ie. wolf, bear, lynx, fox caches or kills) that marten can scavenge play in overall survival?? Is an abundance of larger predators advantageous to marten (scraps to scavenge)?? I know on the coast, both marten and mink will always hit up otter den sites for the fish/ crab , etc leftovers. I would think some of those Fall moose kills, that bears have killed and covered up with sticks/ leaves, that I've flown over in the interior, would be a pretty good winter food source for marten??