Fishers proposed as threatened by the USFWS

On October 6, 2014 the U.S. Fish and Wildlife Service announced its proposal to list the west coast fisher population as a threatened species under the Federal Endangered Species Act.

Fishers have been part of the forests in on the west coast for thousands of years, but now their numbers are diminishing and have virtually disappeared from forests across Washington, Oregon, and parts of the Sierra Nevada in California. Their range was dramatically reduced in the 1800’s because of trapping, pest control, and the conversion of historically multi-aged, closed forests to single-age, open forests through logging, fire, and farming. Current threats include small population sizes, habitat loss and fragmentation associated with logging, severe wildfires, and rodenticides which have become a recent and troubling threat to fisher populations.

The announcement of the proposal initiated a 90-day comment period. The process allows the U.S. Fish and Wildlife Service to conduct a scientific review of the proposal and receive public comment. The final determination on listing the fisher will be informed by all scientific and public comments and is expected by September 2015. More information can be found on this U.S. Fish and Wildlife Service page.

Researchers are currently investigating the direct and indirect effects of each of the identified threats to fishers. Rodenticides have been found in fishers in Olympic National Park, Klamath and Siskiyou Mountains, and Southern Sierra Nevada. Rodenticide use has been documented at illegal marijuana sites on public, private, and tribal lands in California. According to published data (see Gabriel et al. 2012 and Thompson et al. 2013), 58 carcasses were tested for the specific toxin found in rodenticides. Seventy-nine percent tested positive in California, and 75 percent tested positive in Washington indicating an emerging threat to fishers and other wildlife.

Fisher_in_log_Kevin Smith CDFW

Female fisher hiding in a log – Kevin Smith CDFW

In California, there are estimated to be less than 500 fishers in the Southern Sierra Nevada Mountains. In the Klamath Mountains of Northern California and Southern Oregon the population is estimated to be less than 5,000 individuals. Although fishers are found throughout North America, their range on the West Coast has been reduced dramatically, which spurred our current reintroduction to the northern Sierra Nevada.

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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.

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A Transition

Rob Swiers has dedicated as significant portion of his academic and professional career to of Northern Sierra Fisher Reintroduction.  He began working on the project on the Eastern Klamath Study Area using non-invasive genetic sampling and mark-recapture analyses to evaluate the removal of fishers from the population for translocation to the northern Sierra Nevada.  He successfully transitioned the work into his master’s thesis at North Carolina State, completed in 2013. Beginning the same year, Rob assumed the Project Manager position on the Stirling study site as Aaron Facka transitioned back to course work and writing at North Carolina State.  Rob has done a tremendous job keeping track of project research objectives, field staff, budgets, accounting, cooperator communication; in short everything a successful field project requires, and then some.  Thus we are sad to report Rob is transitioning out of the Project Manager position to take on some other project-related responsibilities prior to moving on to other opportunities.

RSwiers-capture 2013


Rob Swiers holding an immobilized female fisher, fall 2013


Rob will be focusing on noninvasive analyses for Stirling and the Eastern Klamath Study Site over the next several months.  A more complete understanding of the rich data set from the Eastern Klamath will further support our understanding of non-invasive protocols and their implementation in Stirling for long-term population monitoring.  He will also be supporting the U.S. Fish and Wildlife Service in reviewing the current state-of-knowledge of fisher habitat selection that will assist the Service with developing conservation guidance for fisher habitat.

Rob, we sincerely appreciate all of your efforts on the project, look forward to your continued investment in our non-invasive analyses and review of fisher habitat selection, and wish you the very best in your next step.

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Fisher poisoning state-wide, linked to illegal marijuana cultivation

Marijuana is a contentious social issue. A component of the debate that is becoming alarming more clear is that illegal marijuana cultivation is killing wildlife and wreaking substantial environmental damage on public, tribal, and private lands. A collaboration of dedicated wildlife biologists, conservationists, and volunteers are working to evaluate the impacts of rodenticide and insecticide toxins used to protect marijuana plants. National Public Radio’s Elizabeth Shogren produced a terrific piece for All Things Considered which aired on 14 February 2014. The story focuses on the impacts on the Hoopa Valley Indian Reservation in northwestern California. The U.S. Forest Service also recently produced a video highlighting the detrimental impacts of marijuana cultivation on national forests.

Toxins used to protect marijuana plants are killing wildlife throughout the range of the fisher. Testing revealed over 40% of fishers in Stirling were exposed to at least one type of toxin. Throughout California the percentage is a nearly-unimaginable 80%. In the Sierra National Forest colleagues found the chances of exposure was related to the presence of cultivation sites, and female fisher survival was negatively influenced by the number of cultivation sites in its home range. We suspect the lower percentage on Stirling has to do with many of the areas roads being gated, which is often not the case in areas with higher rates of exposure. Efforts are now underway to determine how widespread the impacts are to both wildlife and human health and to identify cost-effective methods of removing toxins from the environment.

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Warm winter nights….and happy endings.

When you wake up in the morning, you never really know what the day is going to have in store for you.  We do, after all, carve out our niche in the world by following the daily habits of small furry critters in a predominantly wild landscape.  We often grow attached to our fuzzy wards (how could we not?).  So when something in our data collection portends trouble for one of them, we mobilize to see what we can do.

Males that we capture and deem healthy enough to carry the weight sport ARGOS collars.  These collars communicate with orbiting satellites to determine the collar’s location and the satellites then relay location information via email right to my laptop.

There’s me in the corner!

Armchair biology.  Technology!  While this sounds like a road to obsolescence for field biologists, we still need to track the collar (and fisher) down when the data tells us something is amiss.  The collars are only on during certain times each day, and during this window the collar transmits once a minute to the satellites.  We’ve got a nifty receiver that lets us track it down via strength of the signal and distance from the collar as it transmits.

Male 190 was released in December 2011, and has been with us a little while.  He’s often seen at female den trees during mating season, and all in all, he’s just a sturdy, well built fellow.  It was distressing, therefore, to see some of the data from his collar suggest that he might no longer be with us.  To figure out if 190 was ok Julie and I looked into when the collar transmits and, lucky for us (sarcasm), it transmits from 5PM – 9PM and again from 1AM-5AM.  With the weather being wet as it has been for a time, we knew it was going to be an interesting hunt.  Just what we enjoy, if you can believe it.  We hoped for a dropped collar, and tried not to think about finding a carcass.  It was wet, getting dark, and we were heading into uncertain terrain.

Andria volunteered to go out hunting with me.  With the rain and the wet muddy roads, going in by truck was out of the question. Not to mention our only access was a long and partially closed road that would have required chainsaws, and more time (and daylight) than we could afford.  So ATVs were on the menu.  We knew the area we were headed to, and had a rough route planned (no one had visited this area since the rain, so all routes are tentative).  After dropping the trucks and heading out on the ATVs we began hearing the signal we had hoped for.  We continued on our pre-planned route, as a time or two doing this has taught me that signals broadcast up from a creek bottom can give misleading readings from a ridge top.  Along the way we had to move downed trees and rocks.

After getting all the way down to where our most recent data suggested 190 may be, we could hear no signals from the collar.  This had me daring to think that maybe, just maybe, he’s still alive – but somewhere other than where the recent points told us he might be.  We rushed as best we could back to the top of the ridge and posted up for a few minutes.  Lo and Behold, the signal boomed in to our receiver and continued to change in direction and intensity, quite quickly.  He was not far from where we randomly stopped, doing his thing and probably oblivious to our racket!  

Relief.   Elation.  High fives.  Back to the truck.  We were able to get out there, nose about, and determine that this guy is still hanging around, though probably weathering the worst of the rain in a tree hole somewhere, shielding the collar from reaching the satellites.  A good nights work, and home before 10PM.


UPDATE 2/15/2014:  Activity data from collar came through tonight and shows good readings across the board.  Sweet.

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A Single Hair

It might not look like much. In fact, you might not notice it at all. But a single hair is all Jesse Hogg needs to help tell an important story. Jesse is working with the U.S. Fish and Wildlife Service and other project collaborators as a Klamath Basin Tribal Intern. Jesse began his work with us on the Eastern Klamath Study Area (EKSA) which straddles the California/Oregon border. The EKSA is one of several locations where project biologists captured and relocated fishers to the Stirling District of Sierra Pacific Industries. We are using non-invasive methods to monitor the fisher population of the EKSA to evaluate if the removal of the fishers we relocated was detrimental to the population. Jesse set, checked, and collected hair samples he found in devices designed to snag hair from local fishers. The genetic material stored in the root of hair can reveal an animal’s species and sex and characteristics used to identify unique individuals. After wrapping up a successful season, Jesse is now working in Stirling to help monitor radio-marked fishers.

The Klamath Basin Tribal Internship Program seeks to inspire young native community members to develop the technical skills required to monitor and manage species and habitats, to pursue college-level educational opportunities, and to succeed in conservation-focused careers. The program provides employment and professional development opportunities for members of six native communities of the Klamath Basin of northwestern California and southwestern Oregon.

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Miscellaneous Field Fun

The past few months have been diverse on the project for several reasons. Firstly, radio-tracking takes up a majority of the time spent in the field every week–checking in on up to 8 or 9 fishers a day in their respective territories means a lot of driving! However, before trapping started, finding radio-collared females was no problem, since we knew where each girl’s home ranges were. After the trapping frenzy this fall, it got a bit more hectic as all the females who were re-collared or new females who were fitted with collars began roving around the district like crazy, traveling several miles between days to different locations, and then moving again! However, it has since “settled down” quite a bit as all the females are beginning to settle nicely into their own ranges and are almost always found at any given time.

One of the other aspects of the project after the trapping frenzy of October/November was…yet more trapping! There are a few female fishers whose collars are dying, or who didn’t get captured during the first effort, that we are trying to catch before denning begins so we can check up on them (and give shiny new collars to!). So far, we have not had any luck catching “target” females but we did manage to catch a few incidental critters-as during the first bout of trapping!


Here is a frisky spotted skunk…


And a gray fox-

Ok, I can’t resist throwing in a female fisher captured from trapping in October! She is just too darn cute.


As many of you may know, this is the driest California winter since records have started being kept. Despite this, about a month ago we did get a big dumping of snow, which halted field work for a few days while we waited for roads to be safe to drive again. This was an great change of pace as we were able to see tracks in the snow that we don’t often get to see.

Here is a monster of a black bear’s prints–and my size 8 boot to compare:

2013-12-12 09.17.58

Not far from this was a set of bobcat prints:

2013-12-12 09.18.18-2

After a while, the fun dissipates as the snow melts and all the prints meld together into an indistinguishable muddy mess. In some colder drainages, like this one on Big Chico Creek, the snow made the scenery quite enjoyable:

2013-12-12 12.49.18

But usually, there is always a “view of the day” no matter what the weather is like.

2013-12-14 10.36.04

In a few months, mother fishers will be denning and we will be able to see exactly where they will choose to rest with telemetry and motion-activated cameras-so stay tuned!

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Tracks, Hairs, and Bears, Oh My!

Tracking fishers using VHF telemetry is an extremely useful method for obtaining lots of different information about the animals, it’s also pretty fun! However, in order to implement this method, fishers must be trapped, handled, and fitted with a collar. As biologists, we love having the opportunity to work so closely with a species, but we also love the idea of gathering quality data without ever having to touch an animal. We call this type of data collection “non-invasive”, and it is the eventual goal of this project to use only non-invasive methods to monitor the fishers here on Stirling. In order to reach that goal, we recently ran a pilot study to test how well non-invasive techniques would work in collecting the information we need.

In mid-September, I ran this six week pilot study using track plate boxes fitted with hair snares (see “Field Methods” tab), as well as remote cameras. I placed 45 boxes and 15 cameras in the woods, spread throughout the western half of our district. I checked each box once every 6 to 8 days, collecting tracks, hair and photos that were left behind during that time. The baited boxes attracted lots of different visitors! Bears were especially fond of them; I commonly found the boxes ripped open and dragged away from where I placed them. Gray fox, squirrel, wood rat, ringtail, spotted skunk and even mountain lion are some of the other species I detected.

The most important visitors were the fishers, of course. Adult and juvenile animals, both male and female, investigated my boxes regularly. It appears the non-invasive methods will be a very useful tool for monitoring the fisher population here, and we plan on continuing the pilot study later this year. We are very excited to see what the data will tell us!

Below is a slideshow of images I captured using remote cameras during the study.

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Comings and goings.

Hi Folks, 

We’ve been without an update for awhile, and I apologize for that.  There is always a lot going on, and on top of that we’ve had some changes to our crew.  Some of the crew has moved on to other things, and we’ve gotten some new faces to carry on the work we do out here.

Kevin Smith, the man responsible for a majority of the posts you’re read on this blog (and some of the more interesting stories), has moved on to another project after being with us for 2.5 years.  Kevin is an amazing worker, and was a pleasure to have on the crew.  He helped us all out continuously, and his insight into where our animals were and what they were up to helped the project run its smoothest.  Kevin will continue to do great things working with Pete Figura at the California Department of Fish & Wildlife on their Sierra Nevada Red Fox Project:

The primary study objective is to “investigate and document Sierra Nevada red fox habitat use, reproduction, health, survival, and diet in order to identify factors limiting the its recovery in the Lassen Peak region of northern California.”

Through the use of radio collars that transmit daily location information to satellites, we should be able to track captured red foxes year-round with a high degree of accuracy.  As a result, we hope to identify den locations, monitor reproduction and kit survival, improve knowledge of habitat use and diet throughout all seasons, identify migration routes, and determine causes of mortality.  By taking blood and other samples from each animal captured, we will be able to determine whether they are infected with or have been previously exposed to several ecologically important diseases (e.g., canine distemper, parvoviruses, canine herpesvirus, Toxoplasma gondii) known to affect mesocarnivores in northern California.


We’d also like to welcome Andria Townsend, Julie Shaw, and Jesse Hogg to the crew.  They’ve been with us for several months now, and they’re doing a great job of keeping us in data!  Stop over to the Field Crew page and learn a little about them.  You’ll be hearing from them regularly this year, and we’ve got some cool things coming!

Thanks for stopping in,


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“What’s past is prologue”

For those of you not aware, our annual fall trapping effort on Stirling has been underway for several weeks now and we are getting lots of exciting results. Probably the most exciting, at least for me, is that we recently captured a female (ID: F8B8D) that we released in year 1 (2009-2010) of the project. Capturing this important for a number of reasons and I’ll explain those reasons a bit better a little further along. First, I wanted to give a little history on this female to give some context for why her recent capture in important.

Fisher F8B8D in the fall of 2013 (top) and the in january of 2010 (bottom). We photograph the undersides of all fishers to describe and identify their unique patterns of markings. If you look closely you can tell this is the same fisher by examining her pattern of white blazes.

Fisher F8B8D in the fall of 2013 (top) and the in january of 2010 (bottom). We photograph the undersides of all fishers to describe and identify their unique patterns of markings. If you look closely you can tell this is the same fisher by examining her pattern of white blazes.

Female F8B8D was captured in January of 2010 north of highway 299 and between Shasta and Trinity lakes. We deemed her a good candidate for translocation to Stirling because she appeared to have reproduced in the past and she was in good physical condition suggesting she was mature and good handle the stresses of being hauled off to a new landscape. Like all females in the first year of the translocation she was implanted with a VHF transmitter so that we could track her movements. After she cleared our disease protocols we translocated her to Stirling on January 10th and released her in a tributary of Butte Creek near where most of our year-1 fishers were released. I can tell you she didn’t stay there for very long and the next day I found her on the east side of the ridge in the West Branch of the Feather River. For the next 6 months we often found her on the ridge between these two drainages (see the map of her 2010 home range). Unfortunately, we could never confirm that she had kits, because she never stayed in a den tree for very long. We suspect this may have something to do with the timing of when she was released, but that is another story. In the middle part of the summer F8B8D started moving south towards Stirling city and in fact the final time we found her signal in 2010 she was just to the east of Stirling city. Unfortunately, we were never able to find her signal again and all indications were that the transmitter had failed in early August of 2010.

on the left is veterinarian extraordinaire Diana Clifford, along with ANF, examining fisher F8B8D prior to surgery to surgically implant a VHF transmitter on the right.

on the left is veterinarian extraordinaire Diana Clifford, along with ANF, examining fisher F8B8D prior to surgery to surgically implant a VHF transmitter on the right.




Estimated home range (black lines) of female F8B8D in 2010 as well as the location of her original release site (red star), last known location in 2010 (blue circle) and both recapture locations in the fall of 2013 (red circles). The green line is the access road used for setting and retrieving those traps.

Estimated home range (black lines) of female F8B8D in 2010 as well as the location of her original release site (red star), last known location in 2010 (blue circle) and both recapture locations in the fall of 2013 (red circles). The green line is the access road used for setting and retrieving those traps.

Since we lost track of F8B8D in 2010 I’ve often wondered about what became of her. Each time we’ve trapped she has been a female that I’ve specifically thought about and tried to places traps in her former home range and in places I thought she might have settled into. We never had any success catching her and frankly we’ve had very poor success trapping any female that we released in that first year. In fact, up until this fall we had only recaptured 1 other female from the year-1 cohort and that was back in the spring of 2011. In truth, I had resigned myself to the idea that those females were all dead or were just of the disposition to never be captured again. Of course, not knowing which of those two possibilities were true was a problem because we it left us without important information.

The recapture of F8B8D helps to answer a few of those questions. Or, at the least it gives us insight into what the truth really is. Most importantly, we know that some (at least one) females that were released in year 1 are still alive. Maybe there are more out there living in places that we released them and hopefully giving birth to new fishers that will help to maintain our young population. Now that F8B8D has been recaptured (twice now actually) and collared we can see what her current home range looks like and how it compares to the areas she was using in 2010. We can also see how other fishers have been responding to her current home range by studying their space-use in relationship to hers even while she went untracked. F8B8D was recaptured not too far from the last place we tracked her and so perhaps she has been living in that same area this entire time. We also learned that the implants that we gave these females can remain in them and have relatively little impact on them. Upon removal the transmitter was still intact and doesn’t appear to have done any internal damage. F8B8D was about the same body mass and condition as when we released her and that suggests that she has been making a reasonable living for herself since we released her. Based on her teat size we also think that F8B8D likely had kits in the past year and this demonstrates that the year-1 females are not only living but also reproducing. Now, it’s possible that this is the only year-1 female still alive, and we just don’t’ know for sure, but it is a positive sign.

The underside of Fisher F8B8D showing large teats, indicative of a female that gave birth in the past year. Note that her belly has been shaved so that the implanted transmitter can be surgically removed.

The underside of Fisher F8B8D showing large teats, indicative of a female that gave birth in the past year. Note that her belly has been shaved so that the implanted transmitter can be surgically removed.





Fisher F8B8D in a transportation box after surgery to remove her implant. She was also fit with a new collar, re-vaccinated for rabies and canine distemper, and her general condition assessed. Fishers can be released back into the wild  within a few hours after surgery without any obvious impacts to their well being or behavior.

Fisher F8B8D in a transportation box after surgery to remove her implant. She was also fit with a new collar, re-vaccinated for rabies and canine distemper, and her general condition assessed. Fishers can be released back into the wild within a few hours after surgery without any obvious impacts to their well being or long-term behavior.


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