Monthly Archives: May 2012

Kits, Part Deux!

We’ve recently got some more pictures back from den cameras and verified a few additional kits!  Thus far, we have seen kits from 5 of 9 denning females, for a total of 9.  The other females have either not moved dens yet, or made it past our cameras without triggering them.

714C2, Kits 1,2, &3.

First came pictures of three kits from female 714C2, who was released last fall.  She moved these kits back into her first den (though possibly a different cavity) for a few days, which was something we hadn’t seen before.

Next we saw two kits from 2189C, an animal who was also released last fall and has since made her way to the northeast side of the property.  She has denned up fairly high at ~5500 ft., and interestingly there was a marten that came by her den!

Some of the coolest pictures (in my opinion) from this denning season came from cameras on 182F4’s den.  She brought her kits down the tree and allowed them to explore for a few minutes before they headed off to the new den (only about 50m away).  It appears that females are beginning to spend less time in dens and more time out foraging, which makes the task of finding new dens more difficult.

Anyway, here’s the pics.  Enjoy!


2189C’s Kits 1 & 2.


182F4 letting the kits explore.

Keeping a lookout.











182F4’s kits playing.

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Ominous Signals

The other day Aaron wrote about male 18308, who recently died.  I had the task to go out and locate the collar, so I thought I would expand upon what he wrote and discuss the search process.  I have added a couple of pictures of the remains at the end, and though I don’t think they are particularly gruesome, fair warning.

When we get a mortality signal (VHF), or consecutive days of locations in the same spot (Argos), we know it’s not good.  It’s likely that either the collar has fell off, or the animal has died.  I have been fortunate that in the last year and a half of helping out on this project I’ve only had to search for one other collar.  In that instance it appeared that the animal had simply slipped her collar.

Because Argos collars send us daily locations, I was unaccustomed to searching for them.   I quickly realized that searching for one is a lesson in patience and can be very frustrating.  Our VHF collars that we follow on a daily basis give off a signal at around 60 beeps per minute.  The Argos collars, on the other hand, only give off one signal per minute.  Determining what direction the signal is strongest, which would take seconds with a VHF receiver, takes at least 4 minutes with an Argos receiver.  Instead of a simple beep which we get from a VHF, the Argos reads out a number from 0-239 (239 being the closest).

The saving grace in this search was that I had a couple of points from which to start my search, and these were likely no more than 400m from the actual collar.  I started slowly, heading one direction for a few minutes, and then turning around when the strongest signals reversed.  After an hour of searching, I had ended up back at the truck.  Frustrated as this point I headed off in the opposite direction that I had been going, and after another 45 minutes of searching, finally found the collar (40m from where I parked).

As you know if you read Aaron’s post, this wasn’t a happy ending.  I found the collar, along with very few remains.  In situations like this we try to treat the site like a crime scene, and see if there are any obvious clues to the cause of death.  In this instance I wasn’t able to find much of anything, certainly not anything conclusive.  The location was close to a public road (dirt road but traveled fairly regularly), so perhaps he was hit and then scavenged.  Or possibly he was simply taken by a larger predator (i.e lion).  We sent off the remains to be tested for DNA of possible predators, so hopefully they can give us a bit more insight to the possible cause of death.

Obviously a tough day.  This was the first fisher (and second also) I helped to trap and conduct the physical examination.   It was an awe-inspiring experience to actually see one of these animals up close, and left me with a new-found respect for them.


What was left of the jaws.

Argos collar.

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It is Monday as I check the website ( that allows me access to our Argos data. I go through each tag number, which represents a different male fisher, to see where his travels have taken him and to check his general activities. Today as I get to male 18308 I immediately notice that his collar has been in the same place for 3 days, and the dreaded “0” is unambiguous in the activity data. Those two facts clearly indicate that the male is dead or at the very best has dropped his collar. Tomorrow someone has to go find out which one it is.

Tomorrow (Tuesday) I am scheduled to attend a meeting in Yreka where I will update folks about the translocations’ progress at the Interior Fisher Working Group (a collection of folks interested in fisher biology and management in California and Oregon). Since I’ve committed myself to attend the meeting Kevin volunteers to go find the collar or a dead fisher (or both). I tell him approximately where the collar’s signal is coming from and give him the best locations from our recently downloaded data. I convince myself, as I always do, that all we will find is a collar and no signs that the male is dead.

For most of Tuesday I don’t think much about what Kevin will find. At the meeting I tell everyone that we have documented only 7 fisher mortalities on the project but that this figure might change by the end of today. For most everyone this is a trivial fact and probably impacts the overall tone of my update very little. At about 1 pm I start looking at my phone every few minutes hoping to see a text message that says something about finding only a collar. By five I still haven’t heard anything, and at a quarter to 7 – just before we leave Yreka headed home – I call to see what has been found. The response I get needs no clarification. He is dead.

On the ride home I think about male 18308. I captured him on the EKSA in early 2010 in the first year of the translocation. While he was in the captive facility that year I took to calling him “Big John” primarily just because he was one of the bigger males we had. He was the second male that was released on Stirling and he stayed relatively close to his release location. We tracked him successfully in each year of the study. He was the first fisher we recaptured in late 2010, and he always seemed to be amenable to recapture after that. It’s always exiting to capture our fishers and see how they have done since we last handled them. 18308 was the most exciting to me because he was always the biggest fisher we had (he weighed in at 5.8 kg in February of 2011) and I always wondered how big he would be the next time. We found him at the den trees of females in each year of the study  and sometimes at multiple trees in the same year. Though we cannot yet be definitive I suspect he fathered kits in all three breeding seasons he was on Stirling. He was 6 years old at the time of his death which is pretty good for a wild male fisher. Currently, we don’t know what caused his death and it may take several weeks to learn this – we may never know.  I tracked 18308 for longer than any on the project.

As biologists we probably feel, or at least I do, as though there is some connection to the animals we study. Let’s face it, if I didn’t enjoy working with, and learning about animals, I wouldn’t be doing what I’m doing. At best, the animals are indifferent and at worst they have a deep resentment towards me as I trap and follow them around in their daily lives. Strangely, it is the thousands of hours of effort spent in trapping, handling, and following these animals that causes their deaths to affect me. I enjoy working with and learning about fishers, and each one has taught me something important about what they do and how they live. When they die we lose the opportunity to learn something new about that individual and the species. Maybe just as importantly, we lose the experiences and enjoyment that comes from that learning. I learned a lot from 18308.

18308 at 1st den tree 2010

18308 at best of den tree

18308 after sedation in 2011

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We recently got confirmation of the first kits of 2012, as a couple of female fishers moved their dens!  Although we suspect that nine of the females we are tracking have denned and had kits, it’s nice to get some actual photos of them.

93B5A’s kit.

The first of the year belonged to female 93B5A, who was released in the fall of 2010.  This is exciting because even though she did appear to den last year, we never got any pictures of her kits.  The picture was taken only two weeks after we found her den, and as you can see the kit is pretty small.

The most recent picture of a kit came from fisher 20058, an animal that was released last fall.  This kit appears to be larger, which isn’t surprising as it was moved six weeks after we first suspected she had denned.  It is interesting to see how fast the kits are growing at this stage.

We only captured one kit on camera for each female, but it wouldn’t be at all surprising to learn that they have more.  Although the cameras we use are pretty good, fishers have a habit of getting around without triggering them.  In the case of 93B5A, she returned to the den tree shortly after moving one kit, but the camera didn’t detect her coming back down again.


20058’s kit, another view.

20058’s kit.

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