Sideways dang it. Not sure why so many around. Usually get 1 or 2 a year. My theory is unusually deep snow just to the south where there is large untrapped good habitat. (inaccessible)

Ha. That’s left over from when I tied the whole thing off so it wouldn’t get carried away by spring floods. That set has been there for years and have even caught 2 lynx in it.

Same set, different angle. Sideways again - grr..

Nice, 3 Fingers. They are also starting the mating season in Feb, it's always the best month for trapping them here.

It's so easy to flip pictures on a mac that even I can do it!

Spek is spot on. Wolverine trapping is best in Feb and early March in most areas because they are traveling more, especially the males. I know guys who never see a wolverine track until later in the season. Thats why I was against them shortening up our season. The biologist got it passed so next year our season will close at the end of February despite the fact that her own study showed the harvest male/female ratio was prefect...

Thanks Spek. Ya, Feb and March there is a lot of activity. For many years my average M/F ratio was 1:1 , but past 2 years combined is 6:1 . Seems that what I’m assuming are Females (smaller tracks) stick to the denser forest habitat up small drainages and the males work the valley floor sloughs and ponds.

You are right Yukon. Back in the 50's- 70's our season ran until the end of march for all species. Now, wolverine season here closes at the end of February . So we miss two good weeks of gulo trapping. IMO it could end about March 15th. (Towards the end of March they are sometimes losing guard hair). That's for here, other areas are likely different.

Welcome 3 Fingers. I see the same thing here. Males typically range farther than the females, Although it seems to me that in Feb some of the young females will travel a long ways. Maybe mostly because of mating season and also maybe got kicked out of the house so to speak and are in search of an area of their own to call home.

Three fingers:. Those log pens do you just use a chain saw and build them in place? Then leave them there?

I,m thinking wolverine are like marten. Breed in fall, delayed implantation, birth in April/may.
MT

Partially correct Mike.

MOST breeding takes place late spring early summer., Delayed implantation until late December through January. Most litters are born February through April. I also suspect that latitude and population density are responsible for the large variation in reproductive schedules

Ken, when they were doing the wolverine study here and I could see where it was going I did some research. I found a study done here in Yukon back in the 80s. In that study the bio said that most Yukon wolverine litters are born in December. His thoughts were that was the perfect time due to there being more carrion at that time of year. In this new study the biologist contradicted that info, but IMO her goal was to shorten the season right from the get go. One thing is clear, most females are pregnant during trapping season.

Dave, I think a lot of things are possible where this is concerned. But I would be VERY surprised to see nature arrange things so that litters are born just before the coldest conditions occur. I just doesn't sound right from a survival standpoint. Also I would think that most mom wolverines would prefer deeper snow and warmer temperatures of late spring.

So if litters are born in Dec. has anyone ever caught a lactating female? Anyone caught a female with fetuses in Nov. Dec.? I caught a female with fetuses around Nome. Well developed fetuses. Caught in April.
MT

I think Len posted some pix of a uterus a few years ago but that might have been marten.

I really have problems believing the December litter scenario. Reproduction is so costly to the female 's health that she needs every advantage she can get. Additionally, the kits are mobile and following mom at 8 weeks. I just can't see that happening in late January/February.

Just a bare majority of females breed every year and the viability of the litters is dependent on food for mom. If she isn't in good shape she can't care for the kits and they won't survive. Personally, I think mom has a better chance of finding carrion later in the winter when moose are more vulnerable to wolves and sheep are subject to avalanche mortality

In a search I found several studies that state "it is believed" that breeding can occur anywhere from May through August, with most occurring in June/July, and birthing occurring from January through April with most occurring from February to mid-March. So there is nothing in that cycle of reproduction, that I can see, would account for the very noticeable up-tick in activity during Feb-March that
Yukon, 3 Fingers and I mentioned above. Wonder if it has something to do with the dispersing of the yearlings, (and maybe even the older males?) when the older females start denning in late winter?Or is it something else that triggers that increase in movement? Whatever the cause, February is my favorite month for wolverine trapping.

I suppose it could be our old friend Photoperiod that triggers the movement. The questions is why . What purpose does it serve? I think a lot of it is caused by females looking for den sites and nearby carrion piles or areas with a good supply of squirrels, porkies, pikas etc.

If the females are moving, it sort of makes sense that the males will also be moving just to locate or keep in touch with the girls. I think when you have a species that uses huge territories as a home range, is generally solitary as well as occurring in very low densities..............it makes sense that there will need to be a good deal of searching to find mates. Also, there maybe some machismo going on.

If one or several females are located just prior to denning, it might make sense that a male will patrol the edges of that territory or territories more than he would normally. But let's remember that we same this same type of thing with marten movement in February.

I have seen pairs traveling together in March (twice).....from the air. I have seen them rolling and 'wrestling' with each other. It was clear from the size that it was a male and female.

BUT, when I think of the times that I have scored a multiple catch...........2 doubles and 2 triples...............all four times the animals in each group were same sex. 2 or 3 males or females traveling together. They were all adults too except for a group of 3 females caught in December. Two of those were clearly juveniles. I feel pretty safe in assuming that was a mom and 2 YOY females.

That makes me think again about Dave's biologist claiming December litters. Has anyone ever caught a wolverine that small or even seen a track that could be from an individual that young ??? I know I haven't.

_______________________________________________________________________________________________________________________________________________________________

A good part of the sign I see in Feb is wolverine running in pairs. And I have never caught a wolverine that was lactating, even when our season ran through March.

One of the studies I ran across made the claim that wolverine always den in holes dug in the snow at high elevations. Contrary to this, the dens I have found over the years have ranged in location from holes dug into the ground just below timberline, to holes in the snow up near the peaks. One was a natural hole in a jumble of big rocks just above timberline. One of these dens I found in late January, and showed recent use, but not what I would call heavy use. Another, found in June was in heavy use. The rest were found in May during spring brown bear hunting and all were in heavy use.

From everything I have read, wolverine are inherently difficult to age. Its pretty easy for us trappers to tell YOY from adults, but everything in between is a bit harder. Most of the studies that I have read acknowledged the difficulty in aging, yet agree that age is a factor in reproduction. I know that in the latest Yukon study, one female that was trapped was lactating. To me the whole idea that shortening the wolverine season to protect pregnant females is ludicrous. Every study ever done to my knowledge agrees that females are pregnant throughout the entire trapping season.

I agree Dave. Same is true of marten. It's just a matter of HOW we define the word 'pregnant' .

On the other hand..........what about protecting litters that have been born prior to the end of season ? Be a beneficial thing to protect mom in that circumstance IMO