Pretty long read. Sorry. Do you think there's 2 different species? The Pacific marten (Martes caurina) and the American marten (Martes americana)?


Marten in North America

At the outset of this exercise, let me make it abundantly clear, that the scenario I have described herein is purely speculation, based on the slightest of facts, but, I feel, is a plausible explanation of what probably transpired.
During the Pleistocene, some million or so years ago, the world’s oceans were periodically retracted to varying degrees from what we have currently. Much of the earth’s water was frozen into the continental ice sheets that largely covered the northern parts of continents. Obviously, it was a much different and colder period then than now. Because of this glacial period, which usurped much of the water, there was a land connection between Asia and North America. This dry connection between the now-separate continents is variously called the Bering Land Bridge, or more simply, Beringia. During much of history, during the Pleistocene, this was a relatively broad connection joining the continents, not a narrow isthmus snaking across the waters of the north Pacific. It provided the perfect corridor for migrants.
Now, there probably weren’t mass migrations of every imaginable species (brown bears, red deer, moose, marten, etc.) thundering across this isthmus, coming from Asia into North America. No, the movement was probably much more subtle, taking many, many decades, only progressing a mile or two each year. But many mammals were eventually successful at making their way into North America. This movement happened over millenia, probably not over a year or two. One of the success stories was a relatively small species, the sable, or pine marten. Migrations, even of marten, are still occurring today, although on a much less grand scale. There are pockets and pools of good habitat for marten throughout the mountains of east-central Idaho. These pockets are high-elevation mountain ranges, the Beaverhead, the Lemhi, and the Lost River Mountain Ranges. There are annual migrations between these reservoirs of good populations of marten, still supplementing the genetic pool of resident marten farther west into these mountain ranges – ones who’ve immigrated in previous years. I trap these dispersers, in habitat that would not beconsidered to be “good” marten habitat. Over the years, we have caught more than a hundred marten, in what I would consider poor marten habitat, cottonwood and willow riparian zones surrounded by a sea of sagebrush. These marten we are catching (classed as Martes caurina) in these corridors are dispersers, not permanent residents. They are largely first or second year males, not adults. In fact, since 2008 and 115 harvested marten, only 1 adult female has been taken.
The early dispersers probably occupied various locales in Alaska and Canada. These are what later became the M. caurina line. Most of them were pushed south by repeated continental ice sheets into areas like Idaho, Montana, Wyoming, and Colorado, although many took up residence in glacial refugia, like Admiralty Island in southeast Alaska, that still has M. caurina today. Regardless, most of the early arrivals were subjected to millenia of conditions that were not unlike where their distant relatives had come from (Asia), and their adaptations and changes were minor, but where they adapted slightly to local conditions.
There was yet another period in earth’s history of glacial retreat, this still during the Pleistocene. A second wave of dispersers made it to North America over the same route as earlier (Beringia) and became established. They apparently didn’t contend with as much continental ice as the earlier migrants, and were not pushed by ice to the southern limits. This second wave of migrants had good living conditions farther north of the M. caurina, and became M. americana. Regardless, the two populations were derived from the same genetic background. M. caurina simply had more time to adapt to conditions that perhaps were slightly different. M. americana, being a more recent migrant, has not had a similar length of time (and many, many generations) to adapt.
Subscribing to this scenario, it is easy to see the relationship between M. caurina and M. americana. Being from the same genetic stock they are very similar. What constitutes a valid species? How dissimilar must the genetics be to be classified a distinct species? There are slight differences in their structure and probably very subtle differences in their behavior, but for all practical purposes, they are the same critter.
Up through the late 1930s, most mammalogists considered them two different species (M. caurina and M. americana). (See W. Davis, 1939, Recent Mammals of Idaho). Then, there was a period where they were lumped into a single species (M. americana). Only recently have they again been split into separate species, a designation not applauded nor accepted by all mammalogists.

Pine martin and stone martin? Different there too?.....jk

Many different martins.

Great post Jack.

This subject, has been discussed a lot around my hunting group with regards to whitetails. Here in MI, there are deer in the upper peninsula that are more similar to the whitetails one might see in northern Wisconsin or Canada than the lower peninsula and neighboring states to the south. Obviously varying subspecies, but like you noted, what actually constitutes a "subspecies".

I've always attributed it to simple evolution and Bergman's Rule but maybe there's more to it?


Any taxidermist or processor worth his salt can spot a "UP" deer as soon as they see it enter their shop.

The stone marten is the most basal lineage, and the most "generic"-looking of all true martens (the yellow-throated marten clade is definitely a very separate lineage). There's also the sable, believed to have more adaptations to extreme cold and deep snow, to and the (true) pine marten, which is more arboreal than the sable. There's also the Japanese marten, which split from the pine marten/sable branch about 1.5 million years ago, and it also has a very distinct variety in the south of Japan. Your American martens hopped across the Bering strait at some point (quite possibly, it was several waves of migration) and eventually split into two lineages, which some theriologists consider good species and some don't. But such events are complex, there's always some family drama going on, admixtures, local branching and extinctions, isolation due to glaciers and other factors, bottlenecks, reunions, etc. This process is never linear, so a typical "branching tree of species" is a very simplistic view. In reality, it's usually a mess.

There's also the issue of the concept of species delineation itself. Сurrently it's more of a formality, due to the traditional need to put labels on things, because some species (traditionally treated as good, separate species) in a group may be very close, and others may look almost identical yet have millions of years of independent history, due to inability to produce fertile offspring for instance. It's safer just to speak of lineages and the degree of their difference, because there are good ways to measure that objectively.

Until recently there was no affordable way to study such processes in depth, so a lot was just hypotheses and speculations. Studying the mitochondrial DNA for instance, passed along the maternal line, couldn't show anything past F1 hybrids, so hybridization studies were pretty limited. Studying the full genome (as opposed to just comparing small bits of similar regions of DNA) is clarifying a lot of things but it requires extensive sampling all over the range and lots of work, and it's still pretty pricey. It's letting us see the extent of hybridization and admixtures and the timing of some "events" such as the splitting of different lineages, among other things.

it's funny that our two species of marten (and their hybrids) appeared in good numbers in my region and specifically around my hometown just in time for our project; just a decade ago, they were both vanishingly rare here and their ecological niche was occupied by smaller mustelids (Mustela spp.).

My first marten trapping in Washington involved M. caurina. I was always somewhat disappointed that they did not bring as much money that I would see M. americana brought. But it was obvious why; the fur of the caurina is of a different character altogether than that of the americana. One interesting aspect of the caurina is generally, they are of a more uniform color than the wide ranging colors you will find in a collection of americana.

In 1990, my first experience trapping marten in Alaska was on Admiralty Island in northern SE Alaska. Imagine my disappointment when I saw that the fur looked just like the marten I was used to catching in Washington (they were much larger however). I learned much later that I was trapping in one of the very few areas of Alaska that had M. caurina. I believe that Kuiu Island contains both caurina and americana, that are maybe hybridizing.

Whether they are different "species" or not, I won't guess, but I'm pretty sure they could be separated as different subspecies; like stone marten and baum marten (pine marten).

Always love these informative thoughts. I suspect there can be as much truth to educated brainstorming , as well as rigid lab studies . I feel both are needed and valuable.

Jack, I have saved all your information on marten for some time. I really enjoy learning of these .

Tatiana, I noticed immediately the difference of fluffy tail between those two. Like seeing the European marten with their long black faces and bright orange or ivory necklace bling.

Jack mentioned one type that is large in size and runs in predatory groups on the ground ? Behavior quite different than marten in general. I know I'm branching out into a different category than your original two types mulled on...

My 2 cents on this ?

A wuff is a wuff, is a wuff........

I remember having a conversation with Dr. Tim Hiller (former ODFW Furbearer Coordinator) about the Humboldt marten population on the Oregon coast and whether it was a sub-species or separate species of the American marten. He mentioned that among biologists there were "lumpers" and "non-lumpers".

He was a lumper.

Personally, I'm not qualified to have an opinion....but certainly value Tim's, Tatiana's and yours Gulo. Btw, the Humboldt marten isn't as rare and endangered as they make it out to be...

^^^^^
The non-lumpers from mid 1900's had many different subspecies of M.caurina. There was a trend toward lumping in the later years. I think that may have been due to DNA work, whereas before the advent of DNA research capabilities different subspecies where created based on geographical and simple morphological criteria.

However, now that the antis and climate activist have found that if they have distinct "species", they can then create a lever for making "endangered" species where in reality there isn't a problem for the particular species. In light of that, there has now been a trend back to non-lumping (inventing new subspecies) by those folks with an agenda.

Absolutely right Waggler concerning the agenda of the "distinct species" folks.

Jack, I was going to ask a question but then Tatiana actually touched on the subject.

What is your take on migration in the other direction.....towards Asia ?

More, less, about the same: mixed genera or limited ?

Reasons that would drive migration one direction or the other ?

I would assume that migrations were bilateral. However, migrants to Asia encountered niches that were already filled with mesocarnivores (stone marten, beech marten, sable, yellow-throated marten, etc.) that were pretty well adapted for their conditions, and they were probably swamped. I have recently heard rumblings from the mammalogist community that perhaps American pine marten are conspecific with sable - different subspecies, same species. The sable from northern Primorye Krai aren't much different than our M. americana. Not like the Barguzin sable. Refer to info from Tatiana. Remember, too, that N.A. did not have marten/sable or marten-like animals to migrate until later.

Thanks Jack. If I understand you correctly you are saying that what marten that may have migrated out of NA could have been out competed for resources in the areas already inhabited by Stone, Beech, Sable etc. Also I would think that with their low recruitment, that adaptation to the new environment would have been quite slow with a low probability of success ?

I've noticed that both caurina and americana have that same satisfying odor; sort of a "warm dog" smell, but better.
However, Russia sable (zibellina) although they also have satisfying odor, it is noticeably different.

Back in the late 1980's the Seattle Fur Exchange made some special, one time arrangement, and got a huge collection of Russian sable in for their auction. They had large quantities from sections all over Siberia; west to east. Some sections looked identical to some Alaska sections, while other sections were notably different. One of the sections contained sable put up very similar to how we put them up (those from that section were fairly pale), but all the rest where put up the shortened way, with the exception of a bunch of ranch raised sable. They were huge, and uniformly dark, but imo didn't have much character.

I'll put a wrinkle in the subject ; in some of my flea collecting there are pockets of fleas on red squirrels in Manitoba that are collected in a geological isolated non glaciated region of Manitoba. So the period between 10,000 bp to 100,000 bp was unscraped. The fleas are there but not the rest of the territory. So there are gaps of 500 km between these regions, but the red squirrels are in the biome between these regions.
Connecting the dots sometimes remains a mystery.

by the way Tatiana there appears to be something alive and escaping in your picture.
Good luck with everyone's upcoming trapping season

I have always classified marten into two groups...

Those that go up poles and get caught, and...

Those that walk on by!

Pete

if forgot Vodka can be 70% Ethonal over there.
Wow those are sure some mega sized fleas. One species of flea is only active in the winter found on all mustelides and is the same as " white of the thumb size moon" for reference.
There is another flea species that lives on woodchucks Marmota monax and is 5-8mm long as well

Jack,
You are much more knowledgeable about the subject than I ever claim to be. I catch marten in my area and I see marten from Alaska that look completely different than mine. That being said the current Idaho study scares me to death. If all of a sudden a DNA test can prove its a different species then protections come in. See Humbolt Marten. See Cascade Red Fox. See Pacific Fisher. These types of things are unfortunately used as a weapon to shut down trapping. My two cents.
Rusty

^^^^^^
And logging, road use, banning petroleum, and about anything else that Dems/Marxist want to shut down.

Therein lies the problem, Rusty. Who gets to decide if a different dna sequence is a different species? How different does it need to be? I have every faith in Cory doing the right thing and helping trappers, but I'm concerned that the americana/caurina debate will get others into the fray, and trappers will end up losing. I don't know the extent of his research with Montana FWP, so I'll reserve judgement until I know better.

Jack