More Squirrels and No Scaling on a Mature Sweetgum
Posted: November 14, 2018 Filed under: Camera Trap Photos, Cavities and Feeding Sign, Uncategorized, woodpecker anatomy | Tags: Bark, Campephilus, Carya, Dryocopus, Eastern gray squirrel, feeding sign, Fox Squirrel, hickory, Ivory-billed Woodpecker, ivorybill, liquidambar, Louisiana, Pileated Woodpecker, scaling, Sciurus, squirrels, trail camera Leave a commentI have reviewed the entire late August-late October card and some of the June-August card for what we’ve designated as deployment 5 – a three-years dead Sweetgum stub discussed last summer. Based on approximately six months of data from this deployment, I think squirrels can be excluded as the source of extensive bark removal from mature, thick-barked hardwood boles, just as the data suggest that Pileated Woodpecker can be excluded as the source of scaling on hickories.
The only potential sources of the extensive bark removal under discussion are gray or fox squirrel, Pileated Woodpecker, and Ivory-billed Woodpecker. Pileated Woodpeckers appear to be unable to remove large quantities of bark from hickories in large pieces, and squirrels appear to be unable to do so on the weaker, thinner-barked sweetgums. Based on trail cam captures obtained thus far, Ivory-billed Woodpecker is the likeliest source for the extensive bark-scaling on hickories that we’ve found infrequently in our search area and that I’ve hypothesized is diagnostic for that species.
There were no woodpecker hits on this target tree, but there are multiple sequences involving squirrels. There was minimal little bark removal, and only from previously scaled areas. In fact, I have only detected one visible change to the bark. A small quantity was removed on June 9, between 11:44:13 and 11:44:33. This is shown in the details below.
Squirrels were active on this scaled patch over the course of the deployment, but whatever removed the small strip of bark on the lower right did so during that 20-second interval and was not captured on the trail camera. I think a woodpecker of some sort is probable, since a squirrel would likely have been visible on the trunk in preceding or subsequent frames.
More importantly, squirrels were captured on or around the scaled areas on multiple occasions, and the captures shed light the way they interact with bark on standing boles and what may limit their capacity to remove it.
This deployment ran from August 19-October 21. Squirrels were detected on 17 days and on or near the scaled surfaces on at least 6 of those days. As previously documented, squirrels displayed interest in the edges of the scaling and frequently appeared to be gnawing; however, they removed little or no bark. We now have numerous captures of squirrels on target boles, both scaled and unscaled, and no captures showing them removing bark in quantity or in anything other than small strips.
Squirrels are clearly capable of rapidly and efficiently removing bark from limbs, downed trees, and thinner barked boles. However, I think there are physical limits – body structure and incisor length – on their capacity to remove thick bark from standing boles.
The following images and time lapse clips show what squirrels do when confronted with thicker bark and suggest that when hanging onto a standing trunk, they lack the leverage to remove bark quickly and leave large pieces behind. This should apparent in the selection of stills and video clips shown below as well as in the sequences posted previously. (A brief discussion of squirrels on hickories follows the images.)
Up to now, I have not been differentiating among squirrel hits on targeted trees, squirrel hits on or near scaled surfaces, and squirrel hits in other parts of the frame. Suffice it to say there many, far more than woodpecker hits on both sweet gums and hickories. Squirrels frequently show an interest in the scaled surfaces and also in other damaged areas (like the fracture in the hickory bark shown below). To date we have no examples of squirrels removing any bark from hickories, regardless of condition. It stands to reason that the limits of their capacity on hickories would far exceed what limits their capacity on sweet gums.
A Tantalizing Trail Cam Capture
Posted: August 23, 2018 Filed under: Camera Trap Photos, evidence, Uncategorized, Updates | Tags: 2017, 2018, Campephilus principalis, Eastern gray squirrel, evidence, hickory, Ivory-billed Woodpecker, Louisiana, Luneau video, Pileated Woodpecker, Red-bellied Woodpecker, Red-headed Woodpecker, trail camera Leave a commentBest laid plans . . . I’m pushing back the posts on historic range and evidence but hope to get to them soon.
In going through some of the remaining unexamined images from past trail cam deployments, Geoffrey McMullan came across an intriguing image. He sent me the file for the entire day without indicating where the image was located or what interested him about it. Reviewing cards is challenging; it’s tedious, while demanding focus and attention to very subtle changes. It can be easy to overlook hits of any kind. Nevertheless, this particular frame leapt out at me immediately, even though the object involved is indistinct and is only present in a single frame (more on that later).
I’ll begin by sharing and discussing the image, before and after stills, a time lapse video, and some additional captures comparing other animals with what’s shown in the frame. I’ll follow that with some of the discussion that has taken place among the active searchers in our group and some of the biologists who are advising us. Matt Courtman suggested that everyone on our email list give three reasons they like the image for ivorybill and three counterarguments. Not everyone followed the suggested format, but I’ll draw on those emails as well. I’m hoping this will give you some insights into our process and also give you some additional ways of looking at the image, which I believe to be a picture an Ivory-billed Woodpecker, even as I recognize that it isn’t nearly good enough to stand as proof.
I’ve done my best to present this material in a clear and careful manner. This is not an image that lends itself to immediate, easy interpretation, as some of the discussion reveals. At the same time, a lot can be gleaned from a close, careful look at the raw image, and the preceding and following frames. The various enhancements and comparison captures provide additional context.
A further caveat: I write this blog to maintain a log of our efforts and to share our results with readers on an ongoing basis, in an honest and transparent manner. As with any scientific endeavor, our search is in a constant state of flux. Everything is subject to change and reappraisal based on the evidence. We offer this image with that as background. Most of us believe subjectively that we have found an area that is used by Ivory-billed Woodpeckers, at least periodically. We all recognize that we do not have enough objective “proof” to “convince” third-parties that this is so. The subject image, so far, is just an intriguing part of the mosaic. It’s up to you to decide whether it moves the needle toward “proof” in your mind.
The image was captured on July 12, 2017. The target tree is a hickory that lost its top in a storm in March of that year. And we’ve had a camera aimed at it ever since. This is in area where we’ve found extensive scaling on hickories over the years and where we’ve had a number of auditory encounters. It is within the same contiguous forested area, several miles from the site of the March 2017 recordings. While squirrels are frequently captured on the target stub, there have been few woodpecker hits, and there was no obvious foraging sign on the trunk when I last visited in June.
Perhaps the most informative way to view the image is to step through the time lapse video frame by frame and compare the before, during, and after images. (You may have to download the clip to do this.) This will help clarify what’s object and what’s background. If you’re having trouble downloading the clip (and associated comparison clip), contact me, and I will share the files via Dropbox. I encourage you to click on the individual still frames to see larger, zoomable versions.
Here are two versions the relevant capture, one in its original, unprocessed form and another with a Luminar vividness filter applied, sandwiched between unprocessed captures from 20 seconds before and 20 seconds after. The arrow is pointed at the object of interest.
Here’s the time lapse video clip.
Here is a version of the still, resized using Topaz A.I. Gigapixel, an automated, artificial intelligence-based, image enhancement program. Following that are two enhancements, and a detail therefrom, made using another processor, Let’s Enhance. Both of these programs are automated, so except for selecting enlargement percentage and general processing parameters, I had no influence on the resulting images. Note that the prominent silhouette, which suggests a woodpecker’s head and neck, is blurred, background foliage, not part of the object. Assuming that the object itself is an ivorybill, I think the capture suggests the bird is angled slightly away from the camera, with head and neck inclined to the right.
Edited to add: A significant number of readers have misinterpreted the image, despite my explanation. To reiterate, the somewhat woodpecker head and neck-ish silhouette is background vegetation. The object’s head and neck are not visible. This detail, scaled up as much as possible, should be helpful, despite the loss of resolution.
Next are a squirrel and a presumed Red-bellied Woodpecker (9-11″ including head and tail) captured on a different day. They are included for scale. Both are a little lower on the trunk and are therefore closer to the camera. The captures are followed by a 50-frame Quicktime clip showing both the smaller woodpecker (suspected RBWO) and some squirrel activity. The comparison suggests that the object, which appears to be perched in typical woodpecker fashion, is too big to be a Red-headed Woodpecker (8.3-9.8″ including head and tail) and is slightly larger and more substantial than the head and body of an Eastern gray squirrel (9.1-12″). No tail, head, or neck is discernible, so the size of the object is in the appropriate range for an ivorybill body. (Total length is given as 19-21″ with tail at 5.5-6.7″ and bill at 2.3-2.9″) More discussion, including my responses (in italics) to some questions and comments (in bold and italics), is below.
An ornithologist wrote:
. . . I have tried every possible way to call that something other than ibwo but I can’t make it into anything else. The general impression of size and shape and even posture / body position relative to the tree is spot on.
And then in response to my explanation about the foliage that had caused some confusion:
I was seeing body only, folded wings white patch.
Early on, I had the following exchange with another biologist and ivorybill researcher:
Interesting. First, as I said before, I am no expert on trail cam photos like these. It looks like a black and white object for sure, with white on the bottom, but to my eye it is not possible to determine what kind of object it is. For sure, a bird would make a lot of sense. And if it is a bird, given the location, and pose on the trunk, a woodpecker would make a lot of sense. I am not sure if I see white at the top of the object as well?
How big is the tree that the object is sitting on, and is that scaling on the other side of the tree or remnants from when a branch that broke off? Have you seen bark scaling in that neighborhood?
I replied:
I’m pretty sure that it’s a bird and therefore a woodpecker.
I think I see a white saddle and possibly a dorsal stripe. I also think it is too big to be a Red-headed, based on the squirrel and on a smaller woodpecker that’s on the trunk in another frame from another day; I’ll have to find that image.
The tree is a large hickory stub. What looks like scaling is where bark came off when the top fell. It is in an area that has had a good concentration of hickory scaling over the years.
If you have software that enables you to step through it frame by frame, the movie clip can be very informative. Flip Player is an easy one to use.
The response:
Thanks. I just looked at the entire series step by step with Quicktime and it is very intriguing. One question: could some of the white (or all of it) actually be sky in the background? The other frames show sky in the same location. I am not saying that it is, just trying to rule out possibilities.
My answer (another person raised a similar question):
I don’t think so. To my eyes, it’s pretty clear that the white is on an intervening object. I think the white on the object actually covers some of the dark area (as well as the lighter patch) behind it in the preceding and following frames.
And the conclusion:
Good. It is a very intriguing picture.
There was also this exchange with a consulting biologist:
I replied:
If it’s okay with you, I may include a version of the comment in the blog, anonymously of course.
I can’t prove a negative, but I’d bet my bottom dollar that it’s not a squirrel.
The rejoinder:
Sure, no problem. But let me add the following.
What are the chances of a large woodpecker kind of critter showing up all of sudden in one frame and no sign that it either flew in or left or was in view beyond the one frame 20 seconds or anytime later.
An alternative could be some other sort of critter ( apparently larger than gray squirrel, perhaps fox squirrel, possibly raccoon) that worked up from the ground up the tree and then went back down out of view of the reconciliation.
As you said can’t be sure this is even a woodpecker or any other bird.
Beyond all that, still “interesting” but how many times…
I had one point of disagreement:
I mostly agree – with one quibble. It’s not unusual for birds to show up in a single frame and no others (the probable RBWO in the other clip, for example); it’s much rarer and (more difficult) for mammals to do so.
My correspondent recognized the quibble as a fair point, and it bears repeating that there have been very few woodpecker hits on this tree, probably because it is very recently dead. This exchange also led me to suspect that some of my colleagues were thinking the background foliage was part of the object in question. The discussion ended with this observation:
You are right Mark, I was interpeting the background veg as looking like the neck and head, which really made me wonder why so faded. However, now we have a frame 33 of the Luneau Video situation.
Anyway, thanks for the re-orientation.
Another member of the group also mentioned Luneau, and the similarity is striking, although there’s no accompanying video, and this single capture seems to show more than the Luneau frame.
1) first the obvious, I can’t tell much from the original picture other than it is long and somewhat “thin” relative to more stocky animals. Based on the zoomed in picture, however, it is a live bird; I can see no way it was photo shopped or that it was placed there as a wooden (or otherwise) replicate. I think it is easy to dismiss any attempt at faking it.
Definitely no fakery here 😉
2) The zoomed in image is impressive, it certainly appears to have a white back (which is a slightly different color than the white of the sky next to it) and I see what appears to be two white stripes on the back as well. The comparison of a probable RBWO on the same tree is noteworthy and clearly shows the relative size of the bird in question.
I think the size comparison stands regardless.
Negative concerns –
1) Any of the above positive impressions may be a function of zooming in well beyond the camera’s ability to correctly interpret what’s really there.
Actually, I think that it’s somewhat more compelling unaltered, if you can toggle.
3) The only one frame concern ****** brought up . . . . . . while I don’t think this is a squirrel or mammal of any kind and I’m not at all concerned about this particular series (see below), I am puzzled that the bird in question would not have shown itself on other occasions as well. Are there any pictures of this tree with a PIWO on it? How many pictures (days) do you have images from this camera on this tree? Is the primary foraging area on the other side of the tree? I’m assuming you have several days in not a few weeks worth of pictures on this tree (?)
The camera has been there for over a year, and I’ve gone through countless images. No other suggestive hits. Lots of squirrels. I don’t recall specific PIWO hits on the target tree, although there may have been some, and I’m sure there were at least a few from the deployment. This is one of the targets that has no scaling on it as yet; visits from woodpeckers have been few. As with the RBWO, I suspect birds may be hitting the tree in an exploratory manner at this point and are not staying long.
Just FYI . . . .This is [not far] from where we saw the bird that I ended up thinking was a RHWO and that you weren’t quite so quick to give up on, closer to where I had the long neck and tail silhouette sighting after some ADKs.
An additional note about not concerned about this series and only one frame . . . . .I feel strongly that IBWOs are incredibly wary, much more than we have been assuming them to be. And as any resident bird, it knows its territory very well and that anything “new” or different in that territory could spook it. I hunt as you know, and can vouch that turkeys and waterfowl are often that way . . .one thing out of place from the normal and they leave . . .
With that said, I wouldn’t be surprised, if this is an extremely wary IBW, that it knew something was not quite the same in the area and stayed on the far side of the tree on purpose . . . Even as I type it and re-read it, it sounds a little crazy but since I know about that level of wariness in other species I take it seriously. I know the discussions about wariness and “Tanner’s birds” etc but not sure birds now would act the same way as birds 60 – 80 years ago. If they are that wary, then that also has implications to where the camera is moved. It has to be close enough for a good picture but far hidden well enough to not spook the bird. (If you talk to Tommy or others about new deployment of the camera, my thoughts about how the wariness of this bird is pretty well known and doesn’t have to be anonymous).
I’ve wondered about this myself, and it seems like a pitfall when it comes to putting cameras very close to target trees. With time, however, I suspect birds would become habituated. It’s always a trade-off with these cams, and unfortunately, they have to be placed quite close to the targets.
Thanks for keeping me in the loop Mark – all in all, this has the most “real” field marks and most potential of anything I’ve seen.
I really do think it’s an IBWO . . . it’s at least more cause for optimism and grounds for staying with the trail cam strategy. As I’ve said, I think we’re finally in a position to do it right.
Here’s the response:
Thanks for more clarification Mark – yes I did toggle back and forth, now that I’m not so worried about what I thought was head, neck and bill, the unaltered is more intriguing.
Good to know its been there a year, I agree that birds will get used to it being there over time. The picture has July 17 2017 along the bottom, is that correct or is it July 2018?
I also forgot that this was a tree that you were interested in before any scaling started . . . .that’s pretty exciting and would explain my other concerns about infrequent use and no PIWO use. Pretty exciting in that (if a 2018 picture) the best is yet to come for woodpeckers. Regardless of IBWO, keeping a camera on this tree and having a sequence that shows which woodpeckers use tree, when and how (assuming there are differences based on tightness of bark etc) would be cool from that area.
Frankly, as I was looking at the picture(s), I thought a few times “Damn, I think he got it” . . . . . . Thanks again,
I replied:
The picture is indeed from 2017. But there’s no scaling on it as yet, so it’s worth staying with.
I hope these exchanges help to illustrate some additional challenges related to trail cams, while revealing something about the review process. I think the object in question is an Ivory-billed Woodpecker; so do some of my associates. It’s not proof beyond a reasonable doubt, but it is an encouraging and suggestive piece of evidence.
