Posts Tagged With: pennanti

Spot Trapping

At the end of our Fisher Frenzy last fall, most of us were pretty satisfied with the fruits of our labor. We had captured more fishers than in any of the previous years’ efforts, affixed all of our available VHF collars on females, caught a good crop of juveniles, and all of the fishers we examined seemed to be in pretty good health. What else could we ask for?

Well, there was one question that I couldn’t get out of my head – Where are all of the adult males? We only captured three, and knew of a 4th that was on the air but never captured. This is in contrast to 17 adult females caught during the same time period. Of course, we expect to find fewer males due to their larger home ranges, but only capturing three adults? Something seemed wrong here.

After we finished up our main Fisher Frenzy, the team here continued to run a small number of traps, attempting to target particular fishers that avoided capture. For most of December and January, we didn’t have much success. We kept recapturing fishers that we had caught during the Fisher Frenzy, but the target fishers wouldn’t enter our traps.

However, to our delight a couple of weeks ago, we caught a fisher that we had never seen before. It ended up being a large 4.8 kg male!  He was in excellent condition, and we put a collar on him. He was in an area that we aren’t currently tracking any other adult males (but we did have plenty of traps in this area during the Fisher Frenzy).

Starting to wake up.

Starting to wake up.

Dustin and Pierce monitoring the first male captured.

Dustin and Pierce monitoring the first male captured.

Fast forward three days later. In the exact same trap, another unmarked fisher was captured. Once again, it was an adult male! This guy was slightly smaller than the first (4.3kg), but was also in really good condition. We put a collar on him as well, and let him go.

Capturing these males was important for a variety of reasons. First off, it will allow us to gather some location data on them so we can see what areas they occupy. Secondly, it reinforces to me that there are fishers out there that can go undetected for years, and that we aren’t catching all the animals that are out on the landscape. We won’t know the exact age of these males for a while, but based on their size and developed sagittal crests, both of these guys were probably older than two. This means they avoided capture during the Fisher Frenzy 2013 and 2014, and possibly even 2012. Of course, is could be simply that they spend most of their time outside of the main Stirling tract, and were just now passing through the area for some reason (perhaps scoping things out as we get nearer to breeding season). We don’t have the resources to trap many of the areas adjacent to Stirling, so any fishers occupying those lands might go undetected. Hopefully their collars will give us many good locations over the next year.

Personally, it eased my fears of something more serious going on with the males. It’s hard not to go through all the doomsday scenarios after not catching very many. Possibly they simply aren’t as prone to entering traps as females, or maybe many males are partially occupying areas we don’t end up trapping. Whatever the reason, it was a welcome relief to capture these two guys.

Sean babysitting as he was starting to wake up.

Sean babysitting male #2 as he was starting to wake up.

Andria, Roger, and myself waiting for the drug to take effect.

Andria, Roger, and myself waiting for the drug to take effect.

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First male captured.

Getting a weight.

Getting a weight.

Categories: Field Day | Tags: , , , ,

Dens!

It’s hard to believe that 2013 marks the 4th year that we’ve had fishers on the Stirling district denning and giving birth!  Over the last couple of weeks we have been busy trying to locate dens.  As of today, I am happy to report we have confirmed that 9 of the females we are tracking have settled into behavior consistent with denning (using the same tree over multiple days).  So far we have located dens from 4 of the year-2 translocates, 2 from year-3 translocates, and 3 from fishers that were born on Stirling.  We found the first den this year on March 18th, the earliest recorded over the 4 years!

As Colin pointed out a few weeks back, this year marks the first time that we are able to document fishers that were born on Stirling giving birth to kits of their own.  It is very encouraging to find 3 of these individuals in dens!  We are hoping that within the next week, we will have a fairly complete picture of denning throughout the district (well, those we are tracking).  There are still a couple of fishers that seem to have not settled yet, or that we haven’t been able to get to.

As we are starting to collect pictures from the remote cameras, we have been seeing a lot of males visiting the dens.  In fact, we have documented males at each of the 7 dens that we have retrieved pictures from, with many having multiple males visiting!  Included in these are a few males which have no collar, or collars without any transmitter.  We definitely missed a few during the fall trapping!

I’ve included a slideshow with some of the more interesting photos we have collected so far.  Hopefully it won’t be too long now before we start seeing some kits!

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To Den Or Not To Den?

That is the question. That time of year is rapidly approaching once again, expectant mothers on and around Stirling will soon have to pick their spot and settle down to the task of raising kits. The den season, particularly the early rush to pinpoint natal dens (those in which a female gives birth as opposed to the maternal dens she will use later in the season) is one of our busiest periods on the ground and from a personal perspective, one of the more rewarding.

This will be the fourth season in which Fishers have denned on Stirling since the reintroduction began and again it offers some potential milestones for the project. We have already seen the birth of the first kits sired on the district, the one to watch out for this season is the potential to confirm the first litters born to females native to the district. Although it is very possible that this happened last year we were not actively tracking any females born on Stirling who were potentially reproductive during the 2012 den season. Currently we are tracking 4 such animals and barring any mishaps we expect to locate natal dens for each of them should they give birth this season.

From the table below you can see that this year we are tracking 11 females which we believe could reproduce. Besides the 4 animals mentioned previously we have 5 year 2 translocates, all of which have produced kits previously and 2 year 3 translocates, only one of which has reproduced before.

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Females with the potential to reproduce in 2013

As a point of comparison, ahead of the 2012 season we were tracking 10 potentially reproductive females, consisting of a spread of year 2 and year 3 translocates. Ultimately we confirmed natal dens for each one of these animals.

There is also a slight possibility that some of the 4 females we caught in the fall of 2012 and deemed to have been born that spring were actually born in 2011 and would therefore be able to reproduce this year. So, although we think this unlikely we will have to keep a close eye on what these animals are doing to be sure we don’t miss anything.

Doubtless you will see more from us as we start confirming dens and setting remote cameras. Over the first 3 years we have seen the den season really start to kickoff in late March with our median date of den confirmation (this date can sometimes be a day or 2 later than the kits actual date of birth) being March 30th. The majority of dens are generally found within a week or so around this date although our data shows a spread of about a month for the population as a whole. Our earliest record thus far is March 17th, only 1 week away!

Here is something you’ve seen before to whet your appetites.

714C2

Hopefully new pictures will follow in the next month!

-CAB-

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In The Field With Fishers

Our situation on the ground has been a little hectic over recent months and some of you avid followers may have been feeling a little neglected when it comes to field updates. Well, fear ye no more, I shall share a few details regarding the animals we are currently tracking on and around Stirling as of late February.

We are currently tracking 23 Fishers with active telemetry transmitters on and around the Stirling District. Of these, 16 are fitted with VHF transmitters that we must actively track. 15 of these animals are females wearing VHF collars, the other is a male born on Stirling in 2012 who was given an implanted transmitter due to his age and potential to outgrow a collar. The remaining 7 animals are males of greater than 1 year of age fitted with ARGOS collars, these collars collect locations via satellite and can be conveniently tracked from the comfort of our desks. A breakdown of these animals by year of birth/translocation can be seen in the table below.

Right now we are unable to account for 3 more animals (2 females, 1 male) with potentially active transmitters who we hope are still going about their business out there. They were all born on Stirling in 2012 and have been missing for over a month. Sometimes such animals turn up in unexpected places (see previous post “The Grass Is Always Greener”) or are recovered during our trapping efforts and sometimes we never learn their ultimate fates. Either way, they are young and wild and all we can do is to keep searching.

You can get an idea of the spread of our animals across the study area at the moment from the aerial photos below, to give a little perspective the lines on the image represent the county lines of Plumas to the East, Tehama to the west and Butte in the South.

Female locations:

Year 2 translocates in Yellow, Year 3 translocates in Blue, Juveniles from 2011 in Red, Juveniles from 2012 in Green

Year 2 translocates in Yellow, Year 3 translocates in Blue, Juveniles from 2011 in Red, Juveniles from 2012 in Green

Male locations:

Year 1 translocates in Purple, Year 2 translocates in Yellow, Year 3 translocates in Blue, Juveniles from 2011 in Red, Juveniles from 2012 in Green

Year 1 translocates in Purple, Year 2 translocates in Yellow, Year 3 translocates in Blue, Juveniles from 2011 in Red, Juveniles from 2012 in Green

As you can see we have a pretty wide spread of animals across our study area at the moment, and we are aware of uncollared individuals in many of the intervening areas. As denning season creeps up on us we will be kept busy trying to keep tabs on everyone, this year is shaping up to be an interesting one with more potential dens than any previous year, I will update you all with some of our denning predictions in the near future.

-CAB-

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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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Categories: Updates | Tags: , , , , , , , | 6 Comments

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.

Categories: Updates | Tags: , , , , , , | 1 Comment

Red-tailed Peril

To add to my previous post I thought I’d share one of the more impressive series of images from a den thus far;

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We believe the Red-tailed Hawk you can see entering and exiting the upper left of frame in this series was attempting to steal the prey item being carried by female 199B9 (center frame) to her natal den in April 2011. Whatever the reason, she survived unscathed and went on to occupy 2 maternal dens through the 2011 season before her VHF transmitter finally failed.

-CAB-

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The Great Kit Debate

In a somewhat desperate bid to up my posting rate I’m going to revisit old ground in this post and return to a brief email debate from last April.

And so a brief background is in order…

As we build up to this years denning season we have begun the task of collating and analyzing our camera data from the first two denning seasons on Stirling. As many of you may know the season really begins to heat up in early April as we confirm natal dens (a natal den is the den in which a female gives birth to her kits) by performing walk-ins on stationary females. It is usually on the second walk-in to a given tree that we consider the female has indeed denned. At this point we set a series of remote cameras around the den structure in order to passively monitor the females activities. Through the denning season a female Fisher will usually progress from her natal den through a number of maternal dens (a maternal den being any den occupied after the natal den). Thus one of the most exciting things we see on our cameras is the female carrying her kits out of the den, this gives us a great opportunity to count the number of kits.

So here the debate arises. While going through our pictures of female 17582’s natal den from the 2011 season I came across some familiar images, the first image is of 17582 moving her first kit from the natal den to her first maternal den roughly 100 yards away. Nothing too contentious there.

The picture below was taken 20 minutes later and appears to show her moving a second kit, or potentially a second and third kit at the same time, as the wily Roger Powell contended.

And here is the same image expanded;

So I ask your opinion,

-CAB-

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Springing the trap

Though the aim of our trapping efforts is to catch fishers, we sometimes find non-target species in the traps.  Striped and spotted skunks, ringtails, grey fox, and squirrels are the usual suspects.  Some of them even seem to find the wooden cubby of the trap comfortable!  Last time I caught a ringtail, I opened the back door of the trap and left to do other work.  Upon returning 4 hours later, it was still resting in the box!

Kevin

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Creatures of the night

With the belated and thus far underwhelming winter storms making an appearance recently a few of us have found ourselves with time on our hands away from the field. In light of this situation the ever industrious Aaron has, among other assignments, set us to work organizing a digitalized mountain of trail camera pictures.

As a (more?) naïve youth I used to quite enjoy going through these pictures, then I came to work in bear country…needless to say, the novelty has worn a little thin. For the uninitiated; it is a favorite pastime of black bears to find, wander around in front of and then try to eat trail cameras, this can become a little tedious to watch the 10th or 100th time you see it. Nonetheless, we do get to see some of the more reclusive local residents going about their business too.

I thought I’d share a few recent favorites to add a little color…then I realized they were all night shots.

Enjoy!

-CAB-

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