Heard it through the grapevine...

The goal was to get some flying squirrel photos on the new (is it still new after three months?) Reconyx camera trap and I thought I knew just the place. We have an old massive gnarly black walnut in the backyard with some natural cavities and an impressive dead limb. I figured this might be where my flying squirrels live. So on April 27th at about 630pm I made a set using Squirrel Paste brand (made by On Target and sort of smells like nutty tobacco to me) as the scent lure.
Now, I need to confess right up front that I do not like heights. Even small heights. Any ladder-work is a challenge for me. I have been like this for as long as I can remember. I am not saying I don't do heights, I am saying I don't enjoy doing heights. So even this set at about 12 feet off the ground meant that I needed to negotiate the aluminum ladder each and every time I wanted to check my results.
And I checked them frequently. I checked nearly every day for two weeks. I had to. As the story unfolded, I was tempted to check TWICE a day. But I am getting ahead of myself...

Camera trap in black walnut tree

The Reconyx is ready!

It took 12 hours and 13 minutes for my first capture: a red squirrel. Not the target species but evidence that the Squirrel Paste was doing its job. Note this guy's nose buried in the lure.

Red squirrel on black walnut tree

There were a few more photos of red squirrels on the 28th, but it wasn't until that night that our target arrived! On my second trap-night I captured a visit by a flying squirrel (not sure which species). Please note its nose also buried in the Paste...

Flying squirrel photo with infrared flash

Turns out this was the only visit of a flying squirrel over the two week period. In retrospect, was this just a lucky capture? Imagine how high my hopes were when it only took two nights to get my first flying squirrel visit. Now imagine me trudging up that ladder every single day for two weeks with the increasingly sinking feeling that it was not going to return. On the one hand, I had technically accomplished my goal. But in reality, I was looking for multiple photos (and of much better quality) of multiple squirrels or displaying interesting behavior. In the end, there was no story in the night. The action was all taking place in the daytime and it took several days for me to uncover it.
My first visit to the Squirrel Paste by a gray squirrel came at 8:29am on April 29th. That is a latency to detection of about 38 hours. And again it was obvious that the Squirrel Paste was the draw.

Gray squirrel visiting Squirrel Paste (TM)

Although I went on to capture many images of gray squirrels at this set, the rest all appeared to be unrelated to the Squirrel Paste. In other words, I started catching photos of gray squirrels going about their business. Red, however, seemed to remain curious about the Squirrel Paste:

Red squirrel with nose buried in Squirrel Paste (TM)

But that isn't the story either. Just how many photos of squirrels with snouts full of "Paste" can one write about? (Apparently, four...) No, the story was a different attractant that just happened to also be in the old black walnut. Have a look at the following photo:

Red squirrel

While I was enjoying opening day of spring turkey season (always May 1 here in NY) with my Father, this red squirrel was licking sap off of this wild grape vine. The camera, centered on the Squirrel Paste, almost missed the action. Let's zoom in a bit:

I looked for more. And in very quick succession, I found these:

 

 

I wasn't entirely sure what this squirrel was doing. It could have been a marking behavior or it could have been feeding. If it was feeding, Gray didn't seem to want anything to do with it. Only a few hours later, he trampled past with one of last year's walnuts:

Gray squirrel carrying walnut

Let me sidebar here and explain a bit about what checking photos is like for me. As previously mentioned, I place the ladder against the tree, level it with a small branch and wobble my way to the top. I open the camera and swap SD cards and climb down with great relief. I enter the house, sit at the kitchen table and save all images to my laptop (while wiping the card clean). I then start to scroll through them. With the Reconyx, there can be hundreds of photos each day. I scan through them quickly to see if anything jumps out at me or if I capture anything particularly photogenic for class, Facebook or the blog. And since I had not captured any flying squirrels, I turned more and more of my attention to Red's antics over on the right side of the photos. I have the camera set to take a burst of three images when triggered and it was the following three-photo series that convinced me the red squirrels were feeding on the vine's sap. In the wee hours of the morning on May 2nd, bathed in the glow of the rising sun, this red squirrel showed he was using his tongue, not his teeth, to feed:

Photo 1: The approach

Photo 2: Licking the dripping sap

Photo 3: Not missing a single drop

This was amazing! Did the squirrel bite or "tap" the vine or was the sap running freely from a natural break? Were there other such feeding stations around the yard? Why were there no grays or flying squirrels taking advantage of the meal? Or no chipmunks for that matter? What did it taste like? And as importantly, what had I missed among the data collected from the last five days??? But first things first. It was back up the ladder for me to reposition the camera so it was aimed at the vine and not the Squirrel Paste. 

Once that task was completed, I set down to the more enjoyable job of sifting through the photos collected over the previous five trap-days to see what I may have missed. I encourage my students to think of camera trap photos as data. On this day, they felt more like clues to a mystery. I had to go all the way back to April 30th to find my first piece of the puzzle. Check out this image time stamped 1:16:56 pm

Gray squirrel

I probably only glanced at this photo for a fraction of a second the first time I went through this file. I didn't think it was a particularly compelling image of a gray squirrel then and nothing has changed in that regard. But have a look to the right of the squirrel -- the exact place where Red was so fastidiously tonging in the photos above. Do you see the droplet? Here, let's zoom in...

Grape vine sap

This is the first photo I captured that shows any visible sap from the grape vine. And the very next image actually shows it falling!

WOW! I think I was grinning from ear to ear here at the kitchen table. I mean, who would have ever noticed that drop of sap in the first place? Well, Red did. I took a photo when I re-angled the camera:

Wild grape vine dripping sap

Now I had the camera repositioned to better document the story, and just in the nick of time. Whereas on May 2nd there were only a few scattered visits to the vine throughout the day, on May 3rd it was almost a non-stop lickfest for the red squirrel(s). It takes some agility to reach the sap and I believe Red tried every trick in the book to get at it. Here are some of my favorites:

 

 

And the very best:

The visits were frequent and they often lasted several minutes. I made a stop-motion animation from the photo bursts:

But just as quickly as the visits increased, they began to ebb. 

May 4th: Few red squirrel visits in early morning. Last one at 8:40 am

May 5th: Slight flurry of red squirrel activity at vine at 6:25 am

May 6th: Only three visits. Last one at 10:30 am. No red squirrel photos the rest of the day.

I investigated myself the evening of May 6th.

Inspecting the vine

Vine covered with a white scale. I assume it is whatever was dissolved in the sap

I cannot detect any taste to the white powder

This IS my happy face...

The story was really winding down now:

May 6th: one last capture of red squirrel for the day, but no evidence it was visiting the vine

May 7th: One visit to the vine all day (at 9:50 am), but perhaps just a sniff sufficed:

 

May 7th 12:38 pm: On to other food sources.

 

 May 8 and 9: No visits to the vine. Convinced the story is over, I create new set in our "half-hedgerow" targeting raccoons. 

I never did find any other dripping vines in the yard (and we have PLENTY of grape vines), nor did I find any evidence that the red squirrel or anyone else for that matter had damaged the vine in order to make it leak. I did a little research on the vine sap and as expected, there is much written about it from a gardener or viticultural perspective. I saw several articles that referred to grape vines bleeding. I guess that is as good a term as any.

Thank you for hanging in until the end of this long post. I enjoyed telling the story almost as much as I enjoyed uncovering it. When I ask my camera trapping students to look at their photos and "tell me a story", this is what I mean. Of course, I can't tell a story like this at every set, but then again, maybe I am just not looking close enough...

The Secret Life of Walter Woodchuck

Woodchuck

Last spring, I set a Cuddeback Attack on a woodchuck hole in the backyard. This year, I put a Reconyx on the same hole. The Reconyx is relatively new to me, so I have it set to take a burst of three photos then almost immediately take another burst, etc.etc as long as an animal is there to trigger the shutter. This is both a blessing and a curse. The GOOD news is I feel as if I am missing nothing. Aside from the multiple photos, the Reconyx seems to have a wider cone of detection than the Cuddebacks. The BAD news is I have become quickly overwhelmed with data. And these thousands of images are coming at the busiest time of the semester for me.
So here is my solution: Instead of half a dozen detailed posts, how about one long one with a ton of cool things that have been happening with my woodchuck? Fair enough?

Where to begin? 

Bedding material: In my last post I also wrote about woodchucks and specifically this behavior. I still do not know if this is a female making a bed for her young or a woodchuck just gathering material for its own bed.

Woodchuck with bedding material

 Last year, I created a whole video of visitors to the woodchuck burrow which you can view here. This year saw some interesting characters as well including:

Eastern Cottontail

Blue Jay

WHOA! Look at that photo above again. I have obtained many bird photos with the Reconyx that would have been missed by the Cuddeback. Occasionally, the trigger speed can't keep up with the movement though :)

A final visitor couldn't resist rubbing on the scent mark left by the woodchuck.

Feral cat

That little tree is Walter Woodchuck's favorite marking location. Not his ONLY location, but his favorite:

Woodchuck rubbing on tree

I don't believe I have ever used the word "adorable" in a blog entry yet, but perhaps I should give it a try to describe that photo above...

Walter loves that tree so much he even climbs it:

As I mentioned, Walter leaves scent on other places:

 

 Besides scent marking, Walter likes to stretch. A stretch often leads to a yawn. Observe: 

Now for a series of three...

Well, what happens when Walter STARTS to scent mark but then gets the urge to stretch?

Scent mark? Nope! Gotta stretch..

Woodchuck grooming

Finally, Walter spends a fair amount of time grooming. Although the individual photos are fun to look at, I have taken the series of stills and strung them together for a nice stop action style video. I think its worth the watch: Woodchuck in the sun

I have moved the camera. I am concentrating on other squirrel species now. But I think I will have to revisit Walter later in the season and see what other secrets I can uncover...

Woodchuck action through the lens of a Reconyx

Last year at this time I was playing with a new Cuddeback Attack and its video feature. I wrote

Woodchuck

several blog entries you can check out via the label "woodchuck" at this blog. This year, I decided to put out our new Reconyx camera at the same location and compare the results.
The Reconyx model we have does not take video, but it does take a burst of three photos in a row and then almost immediately is ready to take another burst of three. So I have been playing around with turning those still photos into a video. I am pleased with the results so far.
Two behaviors have emerged this week worth blogging about: Biting and the gathering of nesting material. 

Most, if not all squirrel species bite in order to leave scent behind. The glands are located in the cheek region and the actual bite may serve to anchor the face to the branch or serve as a visual marker or release aromatic chemicals from the wood or....??? :)

Regardless, my woodchuck has been active again this year at the small trunk at the entrance to its burrow. I have captured several nice images of it in action:

Woodchuck biting

Woodchuck biting and scent marking sapling

 

Several species have been captured investigating the entrance including raccoon, feral cat, striped skunk and this red fox. Red foxes will often take old woodchuck dens as their own and I wonder of this one had designs on housing or dinner...

Red fox at the woodchuck hole

Red fox sniffing a woodchuck's scent mark

That was five days ago and the fox has not appeared since.

The behavior I wanted to show is the gathering of nesting material. I only have images of this from a single day, but it happened twice.

I am not sure exactly where we are within the breeding process. Is this a precursor to mating or is this a sign that babies are nearly upon us? Is this a female? And is this even a natal nest being created? Why can't this just be a woodchuck cozying up the place without any expectation that the stork will be making any deliveries? Regardless, the Reconyx takes so many photos that they are of near video quality. I took all the photos associated with this event and put them in Movie Maker. Each still is up for .33 seconds. Have a look:

There are more stories to be told from this camera set. Stay tuned!

Mangy red foxes

I have not one but two sad looking red foxes on the camera traps lately. I am certain they are different foxes as one has retained a poodle-like puff at the end of its tail. I do not know much about mange other than it is caused by mites. The firs photo is from a Cuddeback Capture and the second a Reconyx...


Red fox with mange
(Seneca Falls, NY 3/13)



Red fox with mange
(Seneca Falls, NY 3/13)



One more photo. Last summer, a Cornell University graduate student placed a hair snare on my Father's property with the intention of collecting black bear hairs for genetic analysis. This is one of several photos fromt hat set. It was suggested to me that this bear had mange or some other parasite issue. It certainly looks like a thin coat on the back- compared to the front-half of this bruin. And I can say no other bear showed this pattern, so perhaps this does indicate a problem of some degree.

Black bear with thin coat
(Fremont, NY 8/12)

Are Striped Skunks Symmetrical?

Are striped skunks symmetrical? That might sound like an odd question but I have a very good reason for asking. One way camera traps are used in research is to determine the presence of species in an area. At its simplest, think of this as marking off species on a checklist each time one is

Three striped skunks at bait

photographed. At a more advanced level, multiple cameras are used to determine the presence of a species over a wider area and perhaps a range of habitats. In this case, the researchers are striving to calculate more than the mere presence of a species but maybe its relative abundance or more. And in species where individuals can be distinguished, camera traps can be used to conduct a mark-recapture study to make an estimate of population size.


 Much of the published literature I have seen involving individually recognizable animals involves cat species. Think of tigers, snow leopards and cheetahs as animals with distinctive and unique markings. In North America, our distinctively marked species are fewer and when we further narrow the field to the portion of New York where I camera trap, the list is downright pathetic. White-tailed deer (antlered individuals only!), bobcats (still a real rarity around here) and striped skunks are the mammals that come to mind. Perhaps there are others, but these are the ones I am confident in.
I have written about striped skunks before. In this post from last year, I describe numerous individual skunks photographed on my property. One limitation in determining individuals is that some skunks

Bipedal stance of striped skunk

would be photographed in their left profile while others would be oriented with their right profile to the camera. I could pair camera traps and therefore capture images of both sides of  every skunk that passes by but if I were able to safely say that striped skunks had symmetrical body markings (meaning that their left sides matched their right sides), then I would not need to pair cameras and could compare skunk photos regardless of the side captured by the cameras. Make sense?
Since this original idea came to me, I have conducted an incomplete review of the literature and not found anything written on this subject. Perhaps I am not searching properly or perhaps no one has found the need to write about this. But just maybe I have come up with an idea that is worth answering that has not been formally investigated. I thought an easy way to look at many skunks at once would be to attend fur auctions where trappers bring furs of all kinds to be sold. Alas, that plan has yet to make it to the front burner. And another fur season is past. Fortunately, an opportunity presented itself recently and I was able to obtain 162 muskrat carcasses to use as camera trap bait. I chose one large pile rather than several smaller ones and thought this would be the perfect first test of the brand new Reconyx camera I have access to through an undergraduate research grant. With literally thousands of striped skunk images over the last five weeks, I have some evidence to help me answer my question.

First, here is a look at two very white striped skunks. This photo is from a Cuddeback camera I also placed at the bait pile:

Striped skunks at a bait pile

 Let's call these SK01 and SK02. I only have a single image of these skunks during this visit, so there is nothing to help answer our symmetry question, but clearly we have two individuals so our population is at least two.
This next photo is only two days later and is also of multiple skunks but looky looky it appears to be two DIFFERENT skunks (probably three different skunks as that one in the back just seems much blacker than the two skunks in the first image), SK03 and SK04. I will not go through all the skunk photos in this entry and in fact have a student who is trying to tackle that instead. 

Striped skunks and opossum at a bait pile

I have the Reconyx camera set up to take a burst of three photos together and then to take another series of three as fast as the camera can rearm itself. This makes for many many images of the same individual and for my purposes here, it often provided images of rights and lefts of the same individual.

 Let's start with the photo on the right. As this particular stinker walks towards the camera, we get a sense that he/she is symmetrical. There is a bit of a notch in the shoulder area of both sides and the tail is uniformly white. However, we are missing the whole hindquarter. So what we really need are profiles. I will provide you two individuals in this post just to get us started, but before I do you should stop for a moment and guess at my results: symmetrical or no? I will assume those who would answer "Who cares?" stopped reading long ago....










EXHIBIT A: Again, remember that I know this is the same skunk in both profiles because of the almost continuous nature of the photos from the Reconyx camera.

Note the thickness of the stripe on this skunk's right shoulder or front quarter. Now scroll down and see the left shoulder of this same skunk....

Yipes! Look how thick the white mark is on that side. I was a bit surprised as I really thought my efforts were going to show that these guys were symmetrical. Let's look at one more:















EXHIBIT B: Again a right and a left profile from the same individual

Sigh... Again, there appears to be a marked difference. I have considered the idea that in THIS case, the difference may only be perceived due to body positioning, but I don't think that is the answer. Note that the photos are 12 minutes apart. Well, in that entire time this individual was feeding on the bait. I have many photos of this guy and I think these two represent the profiles the most accurately of them all.

A few words of caution: First, two samples is not enough to draw huge conclusions. And second, the asymmetrical skunks may stand out and were easier to find in my cursory review of the thousands of pieces of data from this camera. But one thing seems certain: Not all striped skunks are symmetrical. That makes the job of estimating their population harder. However, I am a man who tries to look at the bright side of things. I now know I need to photograph skunks from both sides in order to obtain the data necessary to make a proper population estimate. I believe I have just found the justification to ask the grantors for a SECOND Reconyx camera :)