I picked up my fisher. He is my second caught in two years. Last season I picked up a smaller female in the same set.
I wanted to ask if any others are seeing more of these, particularly in SE. Along with that how your marten numbers are looking. Mine are way down this and last season.

Cool. Can you keep them or have to turn them in?

Darn nice catch Mike I'm jealous that is a bucket list critter I hope to catch some day.
Happy New Year !
Allan

Nice!

I know of two others for sure, (1 male, 1 female), this year. 5 last year.
I have also taken 2 in the last 3 years, and marten numbers on my lines are down considerably.
I don't know if fisher have anything to do with it, or not. So many weather anomalies, the past two winters.

AV- I thanks for the reply. I know there are many variables but, the last two seasons stand out in my record keeping as showing marten takes dropping to less than 1/4 of the previous 16 seasons.

Allen M.- I know most guys think the fisher is a cool animal to catch, but I am not on board with it. I am reasonably sure that their expanding presence has affected our marten population.

Smalltimetrapper- We are allowed one per season.

MM.......In order for Fisher to effect your marten population wouldn't there need to be a lot of them around? If there is a lot of them around, wouldn't you be catching more and seeing more sign? I wonder how Fisher effect marten populations in other parts of this continent where they overlap?
mt

I don’t think it would take many. Everything was living at their capacity prior to the fisher arrival. Bigger, stronger, faster always wins.

From what I have read you will not see abundant marten in areas with fisher. I would rather catch one marten than a single fisher.

There are habitats where fisher and marten are found in good numbers co existing.Central Ontario is such a place.A friend of mine that traps near Algonquin park has his basic quota at 40 marten and 40 fisher.
Where I am in the north its a bit different.Years ago(1940's) it was all fisher and no marten,then it slowly switched to all marten and no fisher.Now we have lots of marten and some fisher.
Not sure how the dynamic would play out in your country.
Maybe some trappers from BC who have both marten and fisher could chime in.

Just a guess but I would suspect that marten would do better in deeper snow just because they are lighter.

Also I would think that fisher would have higher calorie requirements due to body size.

Marten litters may be at greater risk from fisher than another predator.

Probably a bunch of variables at play.

If they are moving into SE, they must be moving FROM somewhere else. WHY that is happening might be another interesting question.

Where's Gulo when you need him ??

I put feelers out to Gulo a couple weeks ago, and assume he is keeping an ear to the ground. On the other hand, (couldn't resist, lol), local biologists are taking some interest, but what happens next remains to be seen.

On the line I trapped for 25 years in the central BC interior the fisher stayed basically the same over the years while the marten population has increased. Thus I don't believe fisher have a serious impact on marten and their expansion In the BC interior case. Deep soft snow conditions hinder fisher activity much more than the martens and thus allows the marten to expand more so than the fisher. There are many variables to consider such as habitat change, logging activity, fire and weather condition changes over the years.

Our last 3 winters have been mild, for the most part. No logging or fires, and fairly dry spring and summer weather. Forest habitat is mostly spruce and hemlock.
Very few hares, usually plentiful voles, mice, shrews, and red squirrels. No shortage of porcupine, either.
Geographically, this is a small, isolated area, a strip of land around 3-4 miles wide, and 45 miles or so, long. Bounded on one side by ice fields, the other side by ocean, a very wide, deep river on one end, and a large bay and 3500-4500 foot near-vertical mountains on the other.
It is assumed they travel the large river corridor from B.C., and anecdotal evidence seems to confirm this.
There is little doubt they are reproducing here, but longterm viability remains to be seen.
The area is very heavily trapped, and recent mild winters have allowed trappers access into areas that previously served as refugia, which will almost certainly have negative consequences for marten and fisher, alike.

Boco- I can not fathom this area supporting a marten/fisher ratio nearly equal. Not saying that it is not possible.

AV- I agree the low snowfall and mild winter temperatures over the past years has changed the habitat. My records indicate that the small mammals and birds were nearly nonexistent from 2016 until present. This year they are abundant. Porcupine are still absent.

bctomcat- As with AV your correlation to heavy snow, or lack there of, playing in to marten/fisher numbers. I am certain that the reduced snowfall through the Taku River corridor has allowed the fisher to expand rapidly westward. This goes along with W17’s question of why.

I am still curious if other SEAK trappers are seeing similar trends of fisher numbers on the rise. The region near the Stikine, I would think, should be experiencing a similar trend.

I think a guy in Haines posted a pic of a possible fisher track on the ATA Facebook page
mt

I've been trying my best to catch myself up on the recent scientific literature on fisher/marten interactions before I comment on this quandary. Part of what I will put out here is based on the literature, but (on the other hand) a large part of it is simply a PIOMA based on 50 years of observing of both species in Idaho and Alaska, and talking with other biologists and trappers. Take it for what its worth...

First off...HAPPY NEW YEAR!

1) Interspecific strife (specifically, fisher preying on marten). This is one factor that I give very little credence. I don't see it as a major cause of population changes. Typically, they frequent marginally different microhabitats, exploit marginally different prey bases, and both appear to be very attentive at parenting. I've encountered natal den sites of both species, and I can't imagine, at least when marten are very young, that even a fisher would chance the encounter with an adult female marten. I could be dead wrong, but I would think the chance of serious injury would outweigh the possibility of a few kilocalories.

2) Forest succession and changes. This factor, in my opinion, may have a measurable effect on marten and fisher populations. It appears that in most situations, marten prefer old-growth timber that is largely coniferous. Sure, there are exceptions, no question. But, overall, high marten populations are generally tied to conifers. As habitat changes (through logging, climate, natural succession), in many cases towards more broadleaf forests at the expense of conifers, fisher seem to do better. In north Idaho, 40 years ago most of the higher elevations were marten habitat. Currently, there are relatively large areas, that are predominantly fisher habitat. Is this due to forest changes, and, if so, are those changes due to logging, climate change, wildfire, or what?

3) Climate changes. In my opinion, this may be the single factor most responsible for population density changes in both marten and fisher. Warmer, wetter winters generally favor fisher over marten. Marten are built to be largely subnivean predators. When snow loads are subjected to winter thaws, it becomes more and more difficult for marten to access the under-snow foraging areas. On the other hand, this is precisely the type of snow (either heavy or crusty snow) that favors the fisher. They are obviously much heavier, and their feet are proportionally smaller (surface area of the foot versus mass of the animal), suggesting that they have a more difficult time in powdery, deep snow. There is little question in my mind that the changes that I've seen in north Idaho over the past 40+ years (nearly 50 years), that is, favoring fisher over marten, can be at least partially explained by this dramatic change in type of snow. I'm assuming that the Taku, Whiting, Stikine, and Unuk, have all seen changes in snow density over the past 3-4 decades as well. Further, as the BC trappers have noted, there probably has not been a major change in the snow densities in the more interior regions (yet).

4) Food. Marten are small mammal specialists. Every place I've lived and worked, voles are the prey base that 'runs' the population. Certainly, winter-killed big game might be seasonally important, and seasonal berry crops can be important. Some years, under the right circumstances, snowshoe hares and grouse are equally important in the diet. But the year-round, important component is voles (of at least 5 species, depending on location). On the other hand, fisher appear to rely on a more catholic intake of kilocalories. I did necropsies of 25 Idaho fisher a couple years ago where I looked at stomach contents. Not a large sample, but nonetheless, some interesting anecdata. These were winter-caught fisher carcasses (incidentals turned in to Idaho Fish and Game). Berries, snakes (where were they getting them in winter?), birds, and scavenged deer/elk were being consumed in relatively frequently. If we point the finger at climate change, that too could (and certainly does) affect vole populations to a great degree. Winter chinooks (thaws, rains) that penetrate the snow column are death on subnivean vole populations, and can greatly affect the food source for marten, reducing the available prey a hundred-fold. Are these chinooks more prevalent now than 40 years ago? Fisher, because of their more varied diet, can probably subsist more easily when vole populations crash.

These four potential factors are not independent of each other (changing climate will eventually affect forest type, thus the prey base as well as the access to that prey). So, one size does not fit all. Too, as you are all aware, there's assuredly not a 'silver bullet' that will explain this changeover in every area. Too complicated, as is usually the case with wildlife populations.


Take this assessment for what its worth. Just my 2-cents, okay? I've thought a lot about it over past years, but I'm by no means offering this as a definitive answer.

Again, I hope everybody has a wonderful and wondrous 2020.

Jack

Ping, Jack !

Enjoying your insightful thoughts are as a fine meal to me.

I slow down, take a deep breath, and smile as I slowly digest one paragraph at a time. Then , go back over them as I have the need, in more and more connective tissue building . As I will do here .

Just like studying the nuances in depth of reference photos I see before I begin to put pencil to paper.

Or, layers of the beautiful paper birch ....unwrapping each sheet , deeper each time, to enjoy every tone of rose, apricot, salmon ,ochre....and so on.

Learning in writing is as colour blending, to me.

Thank you for sharing your thoughts around the campfire .

On the surface ...face to the wind ....

Thanks for the insight Jack.

I hope the wildlife troopers make an effort to find the creeps that are tying marten to conifers. That's just cruel !!

Funny!

Jack-I appreciate your weighing in on this. I, like Sharon, had to read and then read again to get full value from your post.