The oldest one I have tooth data for was 14 y/o. A male of course. Haven't seen one that old ever again. What you do see in a steadily trapped population is a declining average age. Now I occassionaly catch a 7 or 8 y/o but most old ones are in the 4-5 range. I have never had a female tooth come back that was over 4.

WOW! 13 years old! I never would have guessed they lived that long. Figured 7-8 was about it. That one must have had all the right moves,(except the last one).
Bearbait; too late. You got the last one.

I've been told you can tell from the sagittal crest on wolves if it's a male or female and the approximate age. Is that true? I have noticed with older skulls (worn teeth) the crest is much larger, but wasn't sure about the male/female ID.

There's an easier way to tell the gender.

LMAO!!

Worn and broken teeth aren't neccessarily an indicator of old age. Many wolves and wolverines will break teeth biting the trap they are caught in. Tooth wear can be caused by what and where a critter normally eats. A marten, mink, wolverine or whatever that lives in an area with sandy soils may chew and ingest a lot of abrasive stuff with his meat, especially in the summer when they may be eating dead fish on the beach or voles with sand in their hair.

Bonnie, the best we can say from the development of the sagittal crest is that it is or is not an adult. We can't be precise in the age of a critter without the use of a tooth. Even then, there are various confidence levels involved. If the animal is very young or very old it may be difficult to say with confidence that the critter was 6 months or 11 months old. Same problem on the upper end.

What's that White? Check the credit card for excess shopping?

Nice skull photos White, explains it clearly. We covered this on the Alaska forum a few years back but your photos are sure to make it easier for anyone to follow.

I have a marten stretcher I mark with a pencil ever year as to the sex and age of my marten. Keeps harvest info right up front and easy to track. 80% of my harvest is juveniles and vast majority males. The longer I stay in an area and the later in the season the more females I harvest. I'm still not 100% convinced vertical sets result in more male harvests.

I just copied a portion of a spreadsheet with tooth data on it. The column headed CC is the confidence level of the technician regarding that particular tooth's age. The numbers following in the NOTES column give the range of age for that tooth.
Crap ! It won't post as a SS. The column of letters A<B are the confidence levels


Species Date Sex Serial# ID # Age CC Notes


MARTEN Nov-96 M 60 4201 0 A
MARTEN Nov-96 M 61 4202 1 A
MARTEN Nov-96 M 62 4203 4 B 4-5
MARTEN Nov-96 M 63 4204 0 A
MARTEN Nov-96 F 64 4205 0 A
MARTEN Nov-96 M 65 4206 3 A
MARTEN Nov-96 F 66 4207 1 A
MARTEN Nov-96 M 67 4208 7 B 7-8
MARTEN Nov-96 F 68 4209 0 A
MARTEN Nov-96 F 69 4210 0 B 0-1
MARTEN Nov-96 M 70 4211 0 A
MARTEN Nov-96 F 71 4212 0 A
MARTEN Nov-96 M 72 4213 2 A
MARTEN Nov-96 M 73 4214 2 A
MARTEN Nov-96 M 74 4215 1 A
MARTEN Nov-96 M 75 4216 1 A
MARTEN Nov-96 M 76 4217 1 A
MARTEN Nov-96 M 77 4218 2 A


Note on the two I highlighted one is YOY and the other an old adult but the tech can't say with good confidence what the actual age is. The old guy might be at least 7 but could be 8. The yoy could be 7 months but maybe 1 year.

White, I love this kind of info when it comes to skulls. I've cleaned so many and they are each so unique in their own way that I find it fascinating that so much info can be gotten from them.

Here is a pic of three skulls I cleaned a few years back. The largest skull is a grizzly bear, the middle is a large black bear and the bottom one is a wolverine. Just for reference, the dog in the pic is about 65lbs. I don't know the ages of these critters as when I was doing skulls back then I didn't ask the skull owner. Anyone care to venture guesses?

My GUESS is that all three of them are youngsters but the wolverine is older than the black bear and at least as old as the brown bear..but then again, maybe not

Nice job on those by the way.

If I remember correctly, on brown bears the root of the canine tooth has a hole in the end that leads up into the tooth. (my guess is that it provides for blood flow or some such. Bearpaw or Moosecaller could help us here). Anyway that hole remains open well into the bears teenage years.

Thank you Another of my side hobbies...lol

I've got a buncha skulls I'm going to clean this spring for myself of various critters and might take a closer look at what I can see as far as age.

And the reason I was asking about telling the difference between male and female, is I don't normally get the whole critter so I can't TAKE the easy way out to look and see

Right. I understood that but couldn't resist.

There are ways to tell but I can't recall the numbers off the top of my head.

For instance; a male marten skull may be 70mm long but not less than 62mm.

The female may be 53mm but never more than 61mm. These numbers are made up for the example. So if you know the correct parameters, you can tell gender.

Or...you can just look between their legs.

Kusko we've already BEEN THERE!! Can't look between the legs if all you have is a SKULL!!! LOL

Well I found these photos and thought this would be a good thread to put them on.
This was the head from an adult female caught in March. You can see the uterine horns with young starting to form in them. Small circles. Four of them.



The question I would have is in the discrepancy of the next two photos.
I would say from the spacing that this is a two year old. Or older?? The uterine horns look mature enough to say perhaps she is getting ready to begin development of her fetus's considering the swollen nature of them or has had a litter the previous year. Which would be my guess. Or is it just the added year of growth that has done this. From my experience in other animals you don't usually see this unless they have either had a litter or in this case perhaps starting to get ready for development..


Opposed to the YOY class with no swollen uterine horns. Or is it a yearling. It is a Feb or March caught Marten. The spacing seems similiar to your photo of the yearling but I would have guess it at a YOY based on relative size to the other marten. ??


Comments from the Marten Guru's

Man, I miss all the fun when I go out for a day to check my coyote line...

Great photos White. Your first photo is assuredly an adult female (duh!).

Second photo is definitely an adult as well, post partus (meaning that she has produced young in the past, further meaning that she is probably pregnant again, but the blastocysts have not yet implanted on the uterine walls for the current year). Therefore, a minimum of three years old.

Third photo is YOY, with thread-like uterine horns and would not have produced young during the ensuing year.

With males, it is apparent that the masseter muscle closure method works well. That is, marten from anywhere in North America will show 0-3mm of muscle closure along the sagittal crest if they are YOY taken during the winter (ie, legal season), and will show > 10mm closure if they are ADU. (About 97% accurate).

Females are much more problematic. Some old ADU females (in excess of 3-yr-olds) will not show muscle closure, and size of the uterus should be noted. I see this about 10% of the time, when masseter closure indicates a YOY animal and uterine horn size indicates ADU. Always, when tooth sectioning is completed, these animals are ADU. Thus my earlier comment (on another thread) about the methodology used when looking at harvest ratios.

If any of you (and I would hope all of you) start looking at your catch ratios, I encourage you all to examine the size of the uterus on all females, as this is a better indication of age than length of visible sagittal crest. Also, strive for more than 4 total young (both sexes combined) per every adult female in the harvest.

One of these days I'll take the time to look into posting photos. Once I figure that out, look out!

Again, White, excellent photos to start us on the long journey toward accurate marten aging.

I'd call that one at least a yearling or long yearling just based on what we can see. Remember too that these gals aren't sexually mature until they are about 1 1/2 y/o. Timing of the catch can give a different view of the uterus also. Caught mid-winter, the uterus may not show an indication of past pregnancies because the scars (corpora albicantia ??? is that right Gulo ?) disappear. Also, if you catch a marten prior to the blastocyst attaching to the uterine wall, they disinegrate rapidly in a dead animal. So if you have one hanging for some time between checks it may give an erroneous indication.

I don't think comparison of body size is ever relevant by the time we are catching them.

Good pix Len. Thanks !!

Sorry. The photos I was referring to in my last post were from FamilyTrapper. However, same goes; Excellent photos, Len. Many thanks...

White,
Unfortunately, uterine scars are not persistent in marten (unlike wolves, coyotes, etc., where you can determine history of litter size back a few years). Corpora albicantia and corpora lutea are actually ovarian scars (not uterine) where the egg has developed in the ovary, and then been expelled. In marten, the egg is released, fertilized, from the ovary and descends the uterine horn. This fertilized egg develops to the eight-cell stage (the blastocyst) but, unlike most species, does not implant on the uterine wall (thus, the term, delayed implantation) for several months. The blastocysts are basically free-floating in the uterus, with arrested development. They don't start to develop until they implant (usually late winter). Thus, you can flush the blastocysts out of the uterine horns with water and a syringe during most of the winter, and count these little guys, giving an indication of population productivity (had they not been harvested).

It gets real complicated, and most of you are probably rolling your eyes. If there is interest, I'll go farther into this...