Posts Tagged With: Pekania pennanti

Young of the Year

It’s been nearly 3 months since we found our first dens of 2015, and we’ve been busy continuing to try and track females and get pictures of kits.  It hasn’t always been easy, and many of the females this year managed to move out of their natal dens unseen.  However, our persistence has finally been paying off over the past few weeks.  So far, we have confirmed a total of 19 kits from 11 denning females!  This averages to 1.7 kits per female, which is on par with what we have found in previous years. Mostly we’ve seen fishers with either 1 or 2 kits, although we did confirm a 3-kit litter from one female.

It’s enjoyable to me to see how fast the kits are growing. In just the last couple of weeks we have started to see some of the kits climbing down trees on their own, and playing around outside of dens (with adult supervision).  In some instances, the kits seem to be following mom to the new den instead of her carrying them.  It also appears from the photos that the females are starting to bring back more prey items to the dens.

At this point, it is very difficult to pin new maternal dens down. The females are out foraging the majority of the day, and since the kits are becoming more mobile it is probably easier for her to pack up and move to a new home.  There are still a couple of females from whom I think we have missed seeing a kit or two.  We will continue to opportunistically walk in on everyone to try and get as accurate of count as possible before the juveniles dispersal in the fall.

Below is a slideshow of many of the kits we have confirmed thus far. I have tried to put them chronologically so you can get an idea of just how fast these fishers are growing up. The first picture is from April 3rd, and the latest from June 8th.  Also, a camera from a log den found about a week ago captured hundreds of images of a female eating a squirrel while her kits were around! I put these into a slideshow you can watch HERE.

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Categories: Field Day | Tags: , , ,

Fisher Frenzy 2014

We recently wrapped up our month-long fall trapping event (aka Fisher Frenzy).  This is the 4th year we have conducted this large scale trapping event, and 2014 proved to be our most successful to date.  Over the course of the month, we were able to capture 32 individual fishers!

We conduct this trapping effort for a variety of reasons.  First and foremost, it allows us to affix radio-collars on fishers.  Most of our collar’s batteries tend to last a little over a year, and thus the collars we put out in 2013 do not have very much life left.  The new collars we put out should last us until next year at this time and allow us to track the fishers throughout the year.  We also learn a lot by examining the fishers we do catch.  We can get an idea of overall condition, age, past reproduction, parasite load, and old or new wounds.  Sometimes, we even get the shock of seeing something completely unexpected, like imbedded porcupine quills!

On a more personal note, trapping is the time of year that we actually get to see fishers (as well as some of the other forest mesocarnivores) up close and personal. This is immensely enjoyable to me, as most of the year it’s rare even to get a glimpse of the fishers we are tracking on a daily basis.

As in previous years, we spent the first two weeks trapping the east side of the district before moving to the west side for another two weeks.  On the east side, we totaled 36 fisher captures of 24 individuals (18Female:6Male).  11 of these were fishers that we had never captured before (6F:5M).  Our success slowed down on the west side of the district, but we did manage 17 total fisher captures of 8 individuals (5F:3M).  Of these, 4 were fishers who had not been caught before (3F:1M).

In total, we ran over 2,700 trap nights!  We recaptured 17 fishers from previous years (14F, 3M), as well as picked up 15 fishers (9F:6M) that we had never caught before.  Our overall trapping success rate for fishers was 1.9%.  Besides fishers, we also capture quite a number of other animals in our traps.  We managed to catch 45 spotted skunks, 32 ringtails, 15 grey foxes, 3 striped skunks, 2 raccoons, and even 1 bear cub (luckily mom didn’t seem to be around).

Every year, there are a few wise fishers that manage to evade our traps.  At the end of trapping, we had 4 known on-air fishers that we did not catch.  Adding those animals to the number of fishers we did catch gives us a “minimum known alive” population size of 36 individuals.  Of course, it’s likely we are not capturing all the fishers that are out on the landscape (we are also not able to trap every area we would like to because it’s not logistically feasible).

In order to run trapping at such a large scale (~100 traps open per night), we require a large amount of personnel, time, and effort.  This year, we had over 25 people come out to help us with our daily trap checks and examinations! All of the project cooperators (California Fish and Wildlife, North Carolina State University, Sierra Pacific Industries, US Fish and Wildlife Service, and Wildlife Conservation Society), made large contributions to help pull this event off.  A HUGE thank you to everyone who gave their time and effort to help make this year’s trapping a success!

Here are a few pictures from this year:

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Categories: Updates | Tags: , , ,

Getting the Point

Getting the Point            

October is long gone and the shortening days of November signal that fall trapping is coming to a close. Unfortunately, we have not been able to update all of you with the happenings as much as we’d like, but I suspect we’ll be putting out more posts in the coming weeks.

One of the parts of trapping, and handling fishers, that I most anticipate is in the moments after we’ve sedated a fisher and get to physically examine it for the first time. One of the first priorities is to  see if it has any major wounds or ailments that need immediate attention or that give us concern. Recently, while examining a female fisher (captured on Stirling in the fall of 2012) we noticed that there was something odd about the area around her right shoulder and neck. Not coincidentally Roger and Kevin both spotted the same thing when I did and all three of us were looking on at several very large, stiff, and prominent hairs jutting from the fisher. I found myself thinking ‘those don’t look like fisher hairs, and I wonder what they are?”. Kevin and Roger were apparently thinking the same thing and nearly in unison we shouted “PORCUPINE!”. A little further examination confirmed our suspicions. Three porcupine quills were embedded in the young female’s right shoulder suggesting she had an encounter with porcupine in the not too distant past.


Close up of 3 porcupine quills in right shoulder of female fisher captured on Stirling in 2014


Female fisher with porcupine quills in right shoulder

Perhaps you are wondering why such a fuss about a few porcupines quills? Well, there are a few reasons that this got us excited, but mainly it was because we have never found a fisher on Stirling with porcupine quills. The discovery is significant because fishers are one of the few consistent predators on the spike-laden rodents when they occur together. As  you probably know, or can deduce, porcupines have all those spikes as more than just a bold fashion statement – they offer pretty good protection from most predators (view a recent video of an African porcupine vs lions). Fishers are uniquely adapted to capture and kill porcupines and they may have an important role in regulating porcupine populations in some areas. Porcupines are large relative to other prey fishers catch and kill (e.g., squirrels and hares) and they provide a large source of energy to fishers (read this if you want to learn more). We have never documented porcupines on Stirling, since we’ve released fishers, and this suggests that porcupines are rare. Having porcupines and fishers on Stirling at the same time might alter the dynamics of how and where fishers forage, their home ranges size and structure, and even their population dynamics.


Porcupine (Erethizon dorsatum)

We don’t know if our female fisher actually killed a porcupine, but she certainly ran across one and we have a pretty good idea of the places she likes to hang out in. For now, it is only a fun little anecdote about one of the fishers on Stirling. Nevertheless, it is an exciting story and perhaps the first in a series of important observations. Such information is one of the reasons we endure a long trapping season and why we subject animals to the burden and stress of capture. Ultimately, it is all important information about what fishers are doing and how their daily lives translate into their ability to persist.


Depiction of a fisher capturing a porcupine (painted by Consie Powell)


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All Eyes On Me

Throughout my career in wildlife work, I have had a number of awe-inspiring experiences.  Often, these are times when I’ve managed to catch a rare glimpse into the life of a wild animal.  While tracking fishers, I have had a few awesome encounters (many of which have been written about in previous blog posts).  A couple of weeks ago, I was fortunate enough to have two experiences back-to-back which I know will stick with me for the rest of my life.


A little blurry I know, but that’s 2 fishers!!

The first of these happened during a opportunistic walk in of fisher F8B8D.  This fisher was among the first group of fishers translocated to Stirling back in ’09-’10.  A few months after her release, her transmitter failed, and we were left wondering what happened to her.  To our delight last fall, we re-captured her!  Since that time we have been faithfully tracking her and learning what areas of the study area she has settled down in.

As the VHF signal grew stronger and I knew that I was getting close, I looked around at the nearby trees for any sign of her.  About 30ft up in a Douglas fir, I noticed a nest.  I’ve found fishers resting in nests many times before, so I moved upslope of the tree to get a better look.  Sure enough, I saw the tell-tale silhouette of a fisher head. I got my binoculars out, and to my surprise I found not one, but two fishers returning my stare from the nest!

The very next day I had a similar experience, only this time it was with a different fisher (36A8B, a two-year old).  This time as I got close, I looked up at a nest and again saw two fishers staring back at me.  As I was looking for a collar to try and identify who was who, 36A8B came into view from a higher branch, made her way down the tree, and briefly joined the two kits in the nest.  I was staring at three fishers!

It’s always very exciting to get a glimpse of a fisher.  Even though I often get fairly close to them while conducting radio telemetry, they are very hard to see, and are usually resting in the cavity of a tree or run away when I try to approach.  This is the first (and second) time in my many years of tracking to get to see a mother with her kit(s)!

Besides from just getting an awesome look at five fishers in two days, these two particular cases were also helpful for us. Both of these females were suspected to den this spring, but we were never able to confirm kits from them with remote cameras.  These visuals confirmed that they had reproduced this year, and have raised at least some of their offspring to this point!  By this time the kits are getting to be pretty large, with the juvenile males being about the same size as an adult female.  It won’t be too long now before the kits will disperse and be on their own.

Categories: Field Day | Tags: , , , , ,

Love is in the Air

Okay, so maybe love isn’t the best choice of words.

The other day I was searching for the natal den of one of our trans-located females.  Having narrowed the signal down, I thought I knew where I needed to go in order to find her.  As I was riding on the ATV past an old road, I caught a “fisher log” out of the corner of my eye.  Now I often see fisher shaped rocks and logs, and 99 times out of 100 they are just that.  This time however, as I backed up to get another look, this particular log turned around and loped off!

I quickly grabbed my gear and started walking after the fisher, thinking it was probably the female I was looking for.  As I walked a ways down the road I realized that although I was extremely close to the female, her signal indicated that she was not moving.  Just then, one of the Argos collared males appeared and started to approach me!  He got about 15 feet away, then moved up-slope towards a large tanoak.  After sniffing around the base of the tree for a few seconds he slowly walked off.  Not surprisingly, this turned out to be the tree the female was in!  This was the first time I have personally spotted a male at a den (although it isn’t too uncommon among the field crew, and our cameras detect it frequently).  It was certainly nice of him to lead me to the tree she was in.

The spring denning time coincides with the breeding season for fishers.  For us on the ground, it is probably one of the best opportunities to spot the males out in the woods.  Males are busy seeking out the females, and just like in this case, often end up at their dens.  I put up a camera pointing at the tree, and it caught a cool series of pictures.


The male in the picture is not the male that led me to the den.  He is un-collared, and appears to be quite a bit smaller than the one I saw there.  It wouldn’t surprise me to catch some larger males visiting the den in the next few days.  This particular female has been in the same tree for a few days now, indicating this this is probably her den.  We are starting to see many of the females we are tracking settling into denning behavior, but more on this in a few days!


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