Posts Tagged With: trail camera

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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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.


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.


Hopefully new pictures will follow in the next month!


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Curiosity killed the cat (sometimes)

Now that we can see the other side of summer we begin preparing for the fall. Last fall we had an extensive trapping session on Stirling where we recaptured a number of our reintroduced fishers as well as several kits. To effectively use our traps we need to have as much information as we can get about where fishers are or where they might be. A big part of getting that information is using our cameras to detect fishers in areas that we might not trap otherwise.

In the last few weeks we have begun deploying our cameras to different parts of Stirling. We will sample an areas for about 4 weeks and them move on to a new area. Cameras are checked once a week and the station is re-baited with chicken (held in a bait sock) and gusto. While going through some of these photos I noticed a black  bear visiting one of the stations. No surprise there since bears come to bait stations quite often, and in fact we find them something of  a burden when they destroy cameras. In this sequence, however, I noticed something else. A black shadow off in the background of the picture -with eyes. Closer inspection shows it to be just an ordinary black cat, but what it was doing at a bait station while a bear was there is a real mystery. It almost appears that the cat is just watching the bear almost contemplating pouncing upon it? Eventually, the bear notices the cat and it kind of wanders away, but never very far.

In this case curiosity didn’t kill the cat (that we can tell), but it demonstrates the interesting, and sometimes weird, things that go on out in the woods. No, its not the find of the century, but its puzzling and a for me kind of amusing. I’d be interested to know what the cat was thinking. Maybe the whole incident was just coincidence.

A cat (red circle in background) watches a bear at a baited camera station


Bear sees a cat a bait station

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Fishers of the North Country

Well since I talked about female fishers yesterday I though it was only fair to give the males a little play today. Fortunately, one male in particular has given us some new and interesting things to talk about. First, a little background is in order.

As some of you might know in the first year of the translocation we had a male that almost immediately after release bolted north about 50 km near the town of Manton. He stayed in that area until his transmitter failed in June of 2010. Some recent photos from that area, just north of Shingletown, CA, indicate that this male is still in the area – though we have yet to recapture this animal to confirm. We grew to call this the “Manton male” for reasons that are hopefully apparent.

In year 2, the first male we released roamed quite a bit. As a matter of fact his satellite transmitter indicated that he was all the way into the central valley (not what we think of as typical fisher habitat) on at least one occasion in January of 2011. Unfortunately, we lost track of this fellow sometime in mid 2011 and we did not know where he had gone until the fall when we captured him near Manton (while we were trying to recapture the original Manton male). In the time since his capture he had not wandered that far from the capture area, and so it appear that this is now a big portion, if not the core, of his home range. So, in two years we had two males that found there way to roughly the same area. By the way, we have no indication that other fishers live in the area.

Okay, so now we are in year 3 of the translocation. Several new males have been released and they all stayed roughly in the areas where we released them. Well, until about 2 weeks ago anyway. On March 12 male 24315 suddenly moved about 15 km north. He then moved further north, you guessed it, to right around the Manton area. In the last several days he has moved another 15 km north of Manton! So, now we have three “Manton males”. I’ve included a couple of maps showing locations for all three of the males I’ve described. The first map is a larger scaled view and shows a good cross section of where we have located all three males. The second map is a closer view of just the northern locations and roughly centered on the Manton area. The second map also shows an approximate time line for male 24315 during the last 2 weeks.

The movements of these males are curious to me because they all went north and stopped or slowed down in the same area. We have had no males travel, and stay, south or east of their release locations though we might predict that we would observe this if males were striking off in random directions. So, why are are we seeing this apparent pattern of males traveling north? The short answer is “I don’t know”. Unfortunately, we still just don’t know enough about what sort of directional or environmental cues males might be using to guide them. Moreover, what resources or restrictions cause them to end up in the same general area is also unknown. The most logical answer is that there are female fishers in the area, but camera surveys in the area – conducted over the last two years – simply do not detect other non-collared fishers. It is possible that male 24315 will come back south. This is after all the breeding season and males have been known to travel a long way to find females. For now, I suppose why these males have traveled north will remain a mystery. So, “if you’re traveling in the north country fare” keep your eyes open and maybe you’ll be lucky enough to spot one of these males in their many travels.

Locations of three male fishers

Time series of male 24315's movements from March 12- March 28, 2012

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DENizens of the Trees

In the last 2 weeks we have managed to confirm that at least 5 of our females have settled into patterns consistent with denning behavior. We detected the first on about March 21 and that is the earliest we have detected a female in a den over the last 3 seasons (more on that  later). Three of the females were released in year 2 of the translocation. One of those females did not den last year and 2 did. The other females were those released in year 3. This is positive because it shows that the females from last year found mates and appear to have had kits. We demonstrated this last year with first year animals, but observing it for the second year adds data and understanding to important population processes. Matt observed a male fisher at female 1F111’s den tree already this year. This was a female released in year 3  and the den is about 11 km east of where we released her. I am still amazed that males show up at den trees seemingly right after females establish them, but since that is a male fishers specialty I guess I shouldn’t be surprised at all.

Black oak den tree

The dens are spread across a big swath of the district. From the west side in the Big Chico Creek Drainage to the east side near highway 70. We even have one female denning on the north side of Deer Creek. We still have a lot of females that have yet to den so it should be interesting to see the distribution of their dens when all is said and done.

Den tree (on right) of female 1F111

The first two years of the project  the earliest we ever found a den was March 23 and most were found after April 1. This year we have found 3 dens before March 23 and another 2 before the 26th, One reason for this might be that we have better access to where females are because we have had relatively little snow accumulate over the winter. The last two years we were snowmobiling/snowshoeing into dens through much of April. Alternatively, the relatively mild winter might have simply allowed females to den a little bit earlier (some anyway) because they were in a better condition. At least three of these females appear to have never given birth before (based on past tracking and physical examination), and this could influence their body condition and timing of birth. All of this is speculation of course, and the bulk of females have yet to den so we might just be observing natural variation in timing of births. It will be interesting to see if other studies detect earlier than usual denning behavior.

We’ll be putting cameras on all the den trees we find to document when females move their litters to maternal dens and to make minimum estimates of their litters sizes. More information to come….

A view of the area immediately adjacent to a fisher den

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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.


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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,


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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.



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