Posts Tagged With: Dens

Young of the Year

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

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

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

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

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Categories: Field Day | Tags: , , ,

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.

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Hopefully new pictures will follow in the next month!

-CAB-

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

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