Fisher Frenzy 2014

We recently wrapped up our month-long fall trapping event (aka Fisher Frenzy).  This is the 4^th 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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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.

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.

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:

Not far from this was a set of bobcat prints:

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:

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

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!

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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Fisher Motion Pictures

Over the last few months, our cameras placed around fisher dens have captured loads and loads of pictures (over 18,000).  We often post some of the better photos to the blog, but there are many that don’t make the cut.  The main purpose of these cameras is to document kits, but in addition they collect all sorts of other information.  We often see various predator and prey species around the dens, males visiting during breeding season, mom bringing back food items, as well as many photos of females simply entering and leaving the den on their daily travels.

We sift through all of these photos, recording what is in each one.  Doing this gives us a little insight into life around the den.  When all the photos from a specific camera are strung together and played like a movie, they are pretty cool to see.  I’ve put together 3 short “motion pictures” from a few of the dens that we collected photos from (the links will take you to a Youtube video):

21392 – Over a month and a half of pictures from the natal den of this two-year-old fisher.  She is a native Stirling born fisher, believed to have had one kit this year.

21FB6 – Pictures from a maternal den of one of the year-2 translocated females.  This spring was her third time denning on Stirling.  This den was one of her maternal dens she first used back in 2011.

23955 – These photos are from a maternal den / rest tree found in mid-July, when the kits were pretty mobile.  23955 is also a native born fisher and this was her first time denning.

Enjoy!

The Grass Is Always Greener

One of the pleasant surprises during the fall trapping was recapturing an adult female, 1E003.  She wasn’t captured the previous fall, so it was the first chance we had to examine her since her release nearly two years ago.  Over the course of her time here, she has been a particularly challenging fisher to follow.  A brief history of this fishers’ time on the Stirling district:

During the spring of 2011, three months after being translocated, she denned and had kits over in the far eastern portion of our study area (at the time further east than any other females we were tracking).  This is a remote area of the district, and where she settled had fewer access roads than other areas.  We failed to capture her during the fall of 2011, but were able to catch a juvenile in her home range.  Through this past spring, we were still tracking her near her usual haunts on the eastern side of the district.  We found her in trees within 100m of each other on several days and believed she was about to den.  Then in mid-April, she vanished.  Her collars’ batteries were due to expire at any time, so we figured that was what had happened.  Thinking she had established a stable home range and would stay there, we weren’t expecting her to make any large movements.

Area covered during 1E003’s move from the east to the west.

Much to our surprise, during a June 2012 flight, we heard her signal again!  This time however, she was on the complete other side of the district. Given the distance from where we normally heard this signal, we were skeptical that this was indeed our fisher.  Instead, we thought it might be the transmitter of some other species associated with a project unknown to us.  For much of June and July we continued to track and estimate the locations of the animal, but we could never confirm that it was a fisher by visually identifying it. Shortly thereafter, the collar disappeared from the airwaves again and we were left wondering if this was actually her or not.  As mentioned above, we captured her during the trapping effort in November, indicating that she had probably been living in this new area, on the west side, since June.  Sometime between April and June she made a 25km trek (as the crow flies) across the district and set up shop in a new area.

IE003 denning area near burn

Naturally, we were left wondering why an animal would make a huge move such as this.  Immediately after being released, translocated fishers often roam around for a couple of months before they settle in an area. Often, juveniles and adult males make large movements as well, but this is more uncommon for an adult female.

This eastern side of the district is much rockier than other areas of the study area, and was hit by a large fire a few years ago.  I remember being surprised the first time I went out there to look for her den that a fisher would settle in this area (you can see in the map the differences in the sides of the district).  It is possible that the pressure of denning and giving birth made her pick and stick to a place that wasn’t ideal.  Since she was released in January, she only had a couple of months to find a good place to den. She may have not had ample time to find the best possible place, and simply chose the best in the area she happened to be in.

1E003’s tracks from a few days ago.

The fact that she was able to survive, and likely raise kits, meant that she was getting enough food and other resources in the area.  However, it could be that with kits reaching adulthood there wasn’t enough to go around.  Possibly there was sufficient food, but maybe there was a paucity of mate choices (few males were known to frequent this area).  Fact is, we will probably never know exactly why she decided to pick up and leave an area she had occupied for over a year, or why she made such a long move instead of finding an area much closer.

Today, I was able to find her in a rest tree, about a mile from where she was re-trapped.  Since we captured her, we have been tracking her faithfully, and are starting to get a feel for the new areas she is using.  We know there are a few other female fishers right around her, so it will be interesting to see how she fits in.

Fisher Frenzy

Fall brings about a good time to try and trap fishers, and we have been very busy over the past month doing just that.  This intensive trapping effort of the Stirling district, dubbed “Fisher Frenzy”, finally concluded this past week.  The trapping that we conduct here serves many purposes (some of which will be discussed in future posts).  Importantly, it allows us to examine the condition of both juveniles and adults, and affix radio-collars on selected fishers so we can track them in the future.  This year, we split the trapping effort between two different sides of the study area, running the first 14 nights of trapping on the eastern portion of the study area, and the last 14 nights on the western side.  When we talk about different sides of the study area, we are using the north-south running Butte Creek as the divider.  This split has more to do with logistics than actual geography.  The sides are accessed from different highways (and getting across the creek is time consuming).

The beginning of this years’ event coincided with the first major storm of the fall, which soaked the lower elevations and left 1-2 feet of snow up in the higher areas of the study area.  This made for a challenging couple of days, and closed many of the traps temporarily.  Luckily, a dry spell followed which allowed us to get nearly everything re-opened, and over the two week period we were successful in capturing quite a number of animals.

On the east side, 16 individual fishers were trapped.  We captured a good mix of both adults and juveniles, males and females.  Total number of fisher captures on this side was 26, with a few animals being trapped more than once.  In addition to the fishers, we caught a variety of other mesocarnivores in the traps.

After the first two weeks we left our comfortable accommodations (the former SPI office in Stirling City) to camp out on western side of the study area.  Again we got a fair amount of rain and a bit of snow, but caught a good number of fishers on this side as well.  Over the final 14 days, we were able to capture 13 individual fishers (17 total).

In addition to only looking at fishers, this year some of the folks from the CDFG Wildlife Investigation Lab and the Integral Ecology Research Center came out to do examinations of some of the other animals that we catch.  Spotted skunks, ringtails, and grey foxes were processed, with the general purpose to look at disease exposure in fishers and these other forest mesocarnivores.

Overall, we are pretty pleased with the way things went.  Between both sides, we caught a total of 29 individual fishers during 28 days.  We know that we failed to capture a few animals (those with collars which are still working), but that is expected.  Some of the animals are in areas that were hard to get to (especially after the first snow), and some seem to just be very trap shy.  Now we have the task of keeping track of all these new animals, and it will be interesting to find out where some of these younger animals will end up living.

Over the entire month, we ran somewhere in the neighborhood of 2500 trap nights.  This was a massive effort that could not have been done without the help of many people.  Specifically, we got some much needed labor from Sierra Pacific Industries, as well as the use of the old Stirling City office so we didn’t have to completely rough it for a month.  US Fish and Wildlife provided many helping hands, as well as a life-saving wall tent and stove in the latter parts of trapping.  Among many other things, Fish and Game provided the mobile lab which made processing fishers less stressful than working them up out in the field. A huge thank you to everyone who came out to lend a hand!

Here are some pictures of the event.  Enjoy!

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Hide and Seek

Fisher 1FE60, a 1 ½ year old male who was first captured last October, has been notoriously hard to walk-in on.  It isn’t that the area he is generally in is especially remote, but has more to do with the fact that he seems to always run away when you start to get close to him.  So I was pleasantly surprised today when I was able to get right on top of his signal without him bolting from the area.  There were, however, a couple of things about this walk-in that were a little strange.

First, I had heard this animal a few hours earlier from a point about three miles south of where I currently was, and the bearing did not point in the direction of where I was now.   Next, the signal I was getting while doing a triangulation (before walking in) was much weaker than I expected, and was going in-and-out like the animal was moving even though it seemed like he was stable.  Finally when I got close, I found myself standing in a rocky area where none of the trees in the immediate area were over 15 feet tall, and I felt the signal was emitting from around one of the rocks.

Because of these factors, I was starting to wonder what I was going to find here.  I have heard of fishers using rocky areas for resting, but I had not encountered it in our study area before.  I looked into the most obvious areas around/under the rock and didn’t see anything.  After about 20 minutes of searching in vain for any sign, I was starting to think that there were a couple of other likely possibilities instead of me finding a resting fisher:

1. There was a test collar (radio-collar not on an animal put out to test our accuracy for triangulations) in the area that I wasn’t aware of which was close to the frequency of 1FE60.
2. 1FE60 was dead and I was looking for remains and an implant.

Both of these things were not what I was hoping to find.  As I searched around the rock some more, I found a small hole that I had overlooked which went down under the rock.  It was definitely big enough for a fisher to fit in, but it was too dark to get a good look into, even with a headlamp.   This left me with a bit of a dilemma.  I didn’t want to leave the area without finding out what was going on, but I sure wasn’t going to stick my arm into a dark hole where there was possibly a fisher dwelling (probably good advice to live by).  I thought about poking a stick into the hole, but I couldn’t help but picture a pissed off male fisher lunging out and attacking me.  With ideas running out, I decided that I would lower my camera down and try to take a picture to see if anything was in there.  With a bit of apprehension I reached down and snapped a picture.

1FE60 under rock.

Hole he was in.

 

 

 

 

 

 

 

 

 

 

 

I guess I made the right decision!  He was probably less than 3 feet away from my camera (and fingers) as I took this picture.  From what you can see of him, it looks like he’s doing all right for himself.

“Fire Ferocious”

“Fire! Fire! Ferocious fire! 
You restless wall of flame. 
Fire! Fire! Roaring higher! 
Your fury to never tame.”

                                     – Mark R. Slaughter

 

Fire is an omnipresent threat to both individuals and populations of fishers. Fires that burn very hot can devastate the over story trees and with them the places where fishers forage, rest, and den. So, we are always aware of the potential effect that a large fire might have on our relatively small population of reintroduced fishers.

In the last week a fire just to the east of our study site (the Chips fire) has been putting up a lot of smoke and growing ever larger. Presently, the fire doesn’t directly threaten any of the fishers we are tracking, but its western boundary is within 5 miles of at least 2 females. Since the fire began on July 29^th it has grown to nearly 16,000 acres and is not predicted to be contained for at least another 2 weeks (see the link already provided).

If you examine the included map you can compare the current area of the fire to the area where the majority of our female fishers have been found (blue dots; these data are incomplete and unedited) and where they have denned (black crosses). Though I have not delineated individual females in this figure you can see that a fire of similar area positioned in the middle of the study site would encompass a large number of dens and female home ranges.  Additionally, when you consider the fire shown here is relatively small (the largest wildfire can be over 100,000 acres) you can begin to appreciate how easily a single fire event could have dire ramifications for any fisher population in the west (in particular reintroductions).

Hopefully, the Chips fire will have little (preferably no) effect on our reintroduced fishers, but as with most things, we just don’t know what will happen. Fishers are obviously not the only species that are threatened by fires (marten are found in or near this fire), but they are our primary focus in this forum. Eventually, fire will likely have some impact on this incipient population. Those impacts will be related to the population size and spatial distribution of the animals. With luck, the population will grow and expand so that it can withstand perturbations such as wild fires.

Map comparing the area of the Chips Fire to female fisher locations