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...

Out on a limb...

Sometimes I am reluctant to pronounce with authority what is happening in my camera trap photos (Going out on a limb so to speak). But this time, I feel I can safely say I have solved "The Mystery of the Barkless Branch". When I came upon the branch in question, my first thought was "This is the work of squirrels!" But I had never seen anything quite like it before. I have seen thinner branches stripped and I have seen smaller patches barked, but never have I seen such a large limb laid so bare. The second thing that gave me pause was this was a downed limb. By the looks of it, it seemed dead rather than a living branch ripped from a tree. So I was puzzled as to who did it and why. A camera trap was in order! Now, someplace on this laptop or in one of the dozen SD cards floating around my workspace are the photos that I took of that limb to show you good people the extent of the damage. I will add them if I ever find them.

Squirrel bite marks
(Stony Brook SP, NY)

As for WHY, I felt there were three options. First, it could be feeding. Squirrels and other rodents  (as well as rabbits) are known to "bark" trees for food. The prize is the tender cambium layer under the bark. Take your fingernail and score a young tree and you will easily find the green cambium layer. Second, this could be a marking behavior. As it so happens, I have been increasingly looking for squirrel bites after first learning of them in February. I wrote about woodchuck bites here. (and remember that woodchucks ARE squirrels). Here is what a typical squirrel bite looks like -->
Notice that it is a long stripe on the tree. The purpose of this biting seems to be to transfer scent from glands on the cheek rather than to feed. The bites themselves never make it all the way to the cambium layer. So what I was seeing on the branch in front of me was nothing like this. But I am no squirrel-marking expert so I was reluctant to eliminate any possibility. Finally, I felt it was possible that the bark was being collected as nesting or winter den material. The only flying squirrel nest I have ever seen was in a bluebird box and was completely made of shredded bark.

Look closely to see the individual incisor marks of the squirrels.

One last shot to give you an idea of how large this stripe is. According to Mark Elbroch, the squirrel bites are likely to be on the sheltered side as this one is -- they are taking advantage of the natural lean of the tree to keep the scent from being washed away too quickly.

As for the WHO, I had several suspects in mind. I was pretty confident this wasn't a bird, but I considered woodpeckers. However, the wood was really not compromised at all as one would expect from a woodpecker. That left mammals and more specifically rodents (this just wasn't the work of rabbits). I was thinking gray squirrel since the are bigger and this was some big damage and the woods were primarily deciduous; the prime habitat for gray squirrels. I remember thinking Eastern chipmunk as well and as it turns out we never got a single image of chippies.

So our game of clue was upon us. Was it Professor Pileated with the candlestick in the library? Or Ms, Squirrel in the kitchen with a lead pipe? Time would tell.....

Here are the results:

First, the most images obtained were of mice. I never saw the mice engaged in any behavior that would account for the damage. It appeared they were using the log as a highway. I made a single composite photo of several mice just for fun:

But the second most common critter was the red squirrel. I didn't really consider this prime red squirrel habitat so I didn't really think of him as a suspect, but perhaps that is exactly WHY he was eating bark. In prime habitat, the red squirrel is eating pine seeds. I am under the impression that bark eating in squirrels is a sign that there is not enough of their preferred food. We had a very poor beech nut and acorn crop this year so maybe that had something to do with this behavior as well.

Red Squirrel
(Wayland, NY 10/12)

I have done this once before but here is a composite image of a gray and red squirrel so you can easily compare their sizes.

Red and gray squirrel compared
(Wayland, NY 10/12)

But its the video that really helps tell the story of what is happening:

Camera trapping with my Black Bear Management class

On Friday, I took my Black Bear Management class to my Father's property in Wayland NY to retrieve 10 camera traps I had set out two weeks earlier. Let's see -- 10 cameras X 2 weeks = 20 camera/weeks. In other words we had squeezed in five months of work into two weeks by setting out so many cameras at once. Special thanks to Lisa Tracy of North Hennepin Community College (NHCC) for assisting with the camera sets.


I conducted a similar field trip last year with my students and had excellent results which I reported here. At that time, I was unsure if we would even get a single bear photo. Well, we obtained several including some nice video. So a approached this year's venture with more confidence. I repeated several of the sets and even used one of the cameras to target rodents instead of bears. So for class this past Friday, we all packed into the van and made the hour-long drive to retrieve the cameras. We were also targeting bear sign and any other interesting natural history finds along the way.

Our total species count (in no particular order):
-Black bear
-White-tailed deer
-Coyote
-Red fox
-Opossum
-Raccoon
-Gray squirrel
-Red squirrel
-White-footed mouse
-Eastern cottontail
Obvious missing species:
-Striped skunk
-Eastern chipmunk
-Wild turkey
-less common species like gray fox and bobcat

Coyote
(Wayland, NY 10/12)

Here are some of the highlights. The first camera set was on the same trail that produced a ten-point buck last year. No such luck in 2012 but a nice coyote and some antlerless deer. The second set was not too much farther, perhaps only a 100 yards away, but produced far more photos. This second camera was set on the mowed ATV trail and even eliminating the photos of Dad going back and forth to his tree stand, we got the greatest variety of species on this camera. Some of the better photos include:



White-tailed deer

Red fox

Raccoon

And our target species, BLACK BEAR

Last year, we had a bear on this camera heading on the other direction. So I believe we have a regularly used path, but an infrequently used one -- in the two weeks, this was the only bear photo at this location.
Set #3 was specifically targeting rodents. I will have to share the full results in another dedicated post, but here is a teaser photo. I stumbled on this downed limb that was being barked. I just HAD to set an Attack camera and get some video of the culprit. Although we photographed several species here, this was the only set that produced red squirrel.

Set #4 was a new location from last year. I saw a faint trail leading into some pines and when we went to investigate, the area was so vegetation-free that it was just begging for a set. We only got one species here, white-tailed deer, but multiple sightings made up for the lack of diversity.

Our fifth set was also a repeat from last year. As we approached the camera, I told the students that LAST YEAR, we had a black bear walk in front of this camera and camera set #2. Wouldn't it be cool if that happened again? Well, it did, except this year the bear was going in the opposite direction. Remember, camera #2 was on the ATV trail. Camera #5 was about 300 yards farther down that trail.

We were excited, but diversions to examine scat and identify trees had put us a little behind schedule. It was correctly pointed out to me that next year I should just plan for that and allot more time. :) Camera trap #6 was a bust. It was Dad's camera and although I thought i put fresh batteries in it, it was inoperative. No photos, and a new project for me this weekend as I am testing it out in the back yard. Camera trap #7 was the one I was most excited to check. Last year I had placed some scent lure into an old rotting log and we managed a nice video of two bears checking it out and one even licking the camera. I am not one to argue with success so I repeated the process this year. Well, we did not get a video of two bears, but we did get two videos of one bear!!! I have combined them below:

Let's discuss the behavior a bit. The lure is a sweet scent that is supposed to smell like something good to eat. This bear shows no signs of trying to ingest the scent or even to find the source of the smell to eat it, but rather looks more like a dog that just needs to roll in whatever stink they just found. the bottle is about four ounces and has now lasted two years. I am anxious to try some more scent luring for bears in the future.

Our eighth camera set proved to be a bust. When the batteries on the Cuddeback Attack get low the camera tends to respond by randomly or continually firing. I can accept that, but by "low" I mean a reading of 75%. To me, that is a design flaw. Anyway, I have to count this set as a total loss, despite the (are you ready?) 847 photos and videos recorded!! None of them were triggered by a critter. That left us with two sets. Set #9 was only a few yards away from #8 and I was silently seething at the failure of two cameras so close to each other. My annoyance soon melted as I checked the captures and found:

As we passed around the little preview camera we brought, I told the students "Fourteen hours ago, a bear was standing right here." It was a nice thought...
Our final camera set was anticlimatic. A few nice photos, some false triggers and no new species. Well, unless you count these creatures --

Brent and Ben
(Wayland, NY 10/12)

The day will come when we won't have to drive an hour to get into serious bear habitat. The "expanding bear range" is only 30 minutes to our south, which includes both of the College's field stations. Bears are resident but still relatively few and far between there. Although the bears have more chapters to write in their story as they move north and increase in numbers, they are increasingly being edged out of the wildlife headlines here in the Finger Lakes by other wildlife stories such as the newly arriving bobcat and fisher. These are exciting times to be a camera trapper!