I recall a spring about 20 years ago when some sort of caterpillar looking larva showed up on the tamaracks. Just when they should have been putting on those new spring needles ! As soon as you cleared the west edge of the Alaska range you could see miles of yellow/ brown tamaracks.
Some were killed but it seems like most survived

The Larch sawfly Pristiphora erichsonii was probably what you saw white 17. Good write up in the Canadian forestry section.
The adult females come out and lay in the new growth shoots their eggs, these curl up so it is easy to see where they are. The tips die off and force the tree to grow new shoots next year. There are no males in this species of sawflies. 10% of the over wintering cocoons do not emerge till the second year. These cocoons are a major food source for the microtone population, so that is why the marten are hunting in those swam regions. They are in the sphagnum moss 5-20 cm below ground depending on moisture depth and the size of the white moon on your thumb = to days worth of food for a shrew. 2 are needed for a red back vole
Part of the food cycle for marten you do not really see.

^^^
So do those cocoons/larvae eat on the fugus you were telling be about back at that NTA convention, or is that something different?

The mice and vole eat the cocoons and that is the search the marten use around the tamarach trees looking for their prey. Most trappers thing the marten are climbing to tree for an out-look post cause they see all this sign around the trees. It also occurs around large spruce trees because there is a bud worm that attacks them and the larvae drop and cocoon under those trees which usually have a taller moss build up.

Recalling back to the convention conservation it was the micro-habitat around forest roads with more light hitting some sides and growth of the plants and the plow zone created clearing roads before topping is put down = high organic zones and fungus growth and more redbacked voles feeding in those areas.

The sawfly larvae fall out of the trees and cocoon in the duff area around the trees they have finished their feeding, they will migrate if not finished to another tree and climb the tamarch and finish feeding. In a heavily infested location 1000 pupae can be in a meter square = bous feeding site for the microtones.
This is another reason that Great Grey Owls are usually around those sites as well since they are exclusively a mouse eater.

^^^^
I'm just trying to figure out why all else being the same (for the most part) marten seem to prefer damp areas vs. dry sites. More fungus??

I don't think it is a matter of marten preferring damp areas.

I believe what we see is a consequence if wet areas freezing. Water is forced to the margins of swampy areas and is forcing voles out of their holes. The marten know this happens and consequently, they are just there taking advantage of the voles being forced to move.
Just like bears with salmon at certain locations

^^^^^^
I realize that many marten trappers are probably not able to see this phenomenon. The easiest place to observe it is in Washington State where climatic and moisture/temperature variations are dramatically pronounced within both a change of elevation and longitude (west to east). These changes are observed within just a few hundred feet of elevation or a couple miles east to west.

This precipitation map illustrates it pretty well. Areas with purple or dark blue will generally have marten providing the habitat is there. That means; not in a clear cut, above timber line, etc.

It is so dramatic. For example, I can drive up a logging road on the west side of the Cascade mountains that starts out at an elevation of 1000 feet, I can then show you within a hundred feet of so of elevation change where you will start finding marten. I tried to explain this to a USFS biologist I was hire to "train" back in the late 80's. He was very skeptical of my explanation of where we would find marten. He humbly changed his tune after the snow fell and we started logging "snow track intercepts" (STI's), and noting the habitat at the STI's.

In the Cascades, marten will typically show up at 3000 feet of elevation. South facing slopes maybe not until 4000 feet or so, north facing slopes somewhat lower than 3000 feet.

Dark Blue 80-100 inches of precipitation annually
Puple 100+ inches annually

More moisture= more fungus = more food for the red back voles or your equal out there. Ever notice that their scat is black vs microtus which eat greens as well and have green scat.

Like your map, Waggler.

Like there, here is the same way. East of the divide is so different than just over the ridges west....and for elevation, I have loved for years, driving up the log roads and seeing how fast the tree types change , very dramatic and obvious to me.

I have places I have to park and admire the trees and habitat as it changes way before I reach the summits.

Around here you will find them from green to purple

I like that map too, Dirt ! I have always loved studying maps- topo for the dimensions especially. They can reveal much about preferred habitat .

As you move north you have other factors at play, but I think it stills has to do with moisture; it doesn't really matter how much of it comes out of the sky in a year, it's how much is in the soil. Permafrost, shorter dry seasons, temperature and other things factor into soil moisture. There are areas of Alaska where if with the same precipitation (arid regions) you were only 30 degree north latitude you would find yourself in a literal desert.

That being said, It wouldn't surprise me a bit if the purple areas on your map may coincide with the highest marten densities in the State.

In a purple area I had seven marten sets widely spread out along five miles of river bottom a week or so ago. Caught 15 marten in two checks over a total of four nights. Still lots of marten around, cannibalized marten, bait eaten from traps containing marten, fresh tracks, etc..
6 juvenile males
5 adult males
3 juvenile females
1 adult female

^^^^^
I think maps like these are fascinating, they can explain things and help form hypotheses.

I would be interested to hear others thoughts on lemmings ( bog) as a food source. Some of the highest densities of marten tracks Ive ever seen were in an area with an unbelievable population of lemmings. I have never trapped that area, but have hunted it extensively. Late in the fall when the snow comes the marten sign is incredible.

Dirt, I have questioned the home range theory too. [/quote]

In northern Manitoba where the two species of lemmings occur on the sub-artic / taiga interphase area the trappers have good populations of marten. Gilliam area 56.3N -94.6E and east towards Ontario boarder. When some snap trapping for small mammals was done for a Hydro study they were hearing the traps go off behind them on the trails. They had to go back and string tie the snap/ wooden rat traps down because the marten were taking them away in front of the researchers. In the end they quit because of the number they were catching. Those populations went on for several years in that area if I remember correctly.
70% of those marten are 3xl from those trappers when they can get out on their lines.

Well with all the talk of fleas, lice, and mites......

What caused that,T4E,Never seen that before on a mink or marten.
I think they would freeze to death here this time of year with that amount of fur loss.

There are two types of mites and I always get the wrong on. I'm leaning towards that being a Sagunicropic mite. the other is Scabies
T4 E I will pm you where to send the samples.

on the underside of the hide you see the burrows in the leather....if you want to risk infecting yourself.

I don't know what happens to mink when they get the kidney worm but they do go down very fast mid -winter. When this effected the local population it all but whipped them out for 5 years. and that was back when a mink was worth a good bottle old Single Malt Scotch. Maybe Gulo will chime in.

So the neighbor gave me this book the other day. " The Patterson's Den" It is an autobiography by a guy who moved out here in 1941. Trapped with his dad on about a fourth of my line. According to him it appears there were no marten down on river. They had to trap up at 1000 ft to find marten. There were 4 other trappers working the low country around him and he inherited his line. Maybe they were poor managers?