Trip Report December 16-21, 2016, Part 2

Part 1 of this report is here.

Patricia opted to take the day off on the 19th, so I went out on my own and covered a lot of territory. I had been thinking hard about the hickories and the fact that, in virtually all cases, we’ve seen indications that bark is removed from these trees and stubs within a very brief period or perhaps in a single visit and that other woodpeckers don’t seem to begin working heavily on these trees for extended periods, sometimes for years. Except for changes in color due to exposure to the elements, some of the scaled surfaces we associate with Ivory-billed Woodpeckers can retain their distinctive appearance for at least three years and more likely five or more.

Steve Pagans later explained that this is due in large part to hardening by compression; hickory wood is hard and dense to begin with, and when a tree or stub is leaning, the wood that’s absorbing more weight becomes even denser, harder, and more impervious to rot. Thus, on many of these trees, Pileated Woodpeckers will have worked on the rotting side, sometimes extensively, while the compressed side remains very hard and virtually untouched by woodpeckers.

I examined and marked as many of these trees as I could over the remainder of the trip. Unfortunately, we did not find any of this scaling in the 2015-2016 season. Trying to find more of it this year and trying to find a way to identify potential target trees before they’re scaled will be priorities for me.

I plan to write about this work on hickories and what I think it suggests in an upcoming post. For now, suffice it to say that these particular snags and stubs are a kind of twofer having the decayed substrate that’s preferred by Pileateds and and the hard wood that, following Tanner, is preferred or used exclusively by ivorybills. As noted elsewhere, some bark on these snags and stubs can remain tight for years, and on one of the trees I examined, it was still difficult to remove, even when it had reached a point at which some of it would crumble to powder when it was being pulled off. More importantly, the harder surfaces show modest expansion of exit tunnels and targeted digging work that appear to be associated with the initial scaling (as in the hickory on the homepage and the one in Steve’s photo at the end of this post, both of which were very freshly scaled and alive when found) and little or no other work for a period of years, even when there are signs of infestation by multiple insect species (based on the presence of exit tunnels that vary greatly in size and shape). I’ve included multiple examples, long shots and details, to illustrate.

On the 20th, Patricia, Steve, Phil, and I went to Sector 2 together. We went through the area where I recorded calls in 2013 and where we found concentrations of scaling in spring 2012 and during the 2012-13 season. There has been none since in this little patch. We found no recent looking bark scaling in the morning (as it turned out, we missed a group of three sweet gums with high branch work perhaps a quarter mile to the northeast of this area, see below.) One odd highlight was coming across a patch of forest floor with many of these beautiful ice formations that had formed around the stems of a couple of species of plant.

imgp4065

At a little before noon, Steve opted to turn back; we had already covered 2.3 miles. Before we went our separate ways, we all speculated on and were baffled as to what might have damaged this sweet gum. The wounds seem to have been caused by a scrape, but there were no downed trees or tops anywhere in the immediate vicinity.

imgp4107

Phil, Patricia, and I proceeded another half mile farther north, reaching a hickory stub that I found in the spring of 2013, shown below. The stub was still standing, and the areas with putative ivorybill work had lost more bark but showed no signs of further woodpecker activity. The presence of a click beetle in this 2013 photo suggests that parts of the tree were already starting to rot even then.

FWHickory1

We found two sweet gums with extensive scaling on large branches within 30 yards of this snag. Some of the work was recent. This is something that we’re finding repeatedly; even within clusters, the interesting feeding sign often seems to appear in tighter groupings involving two or more trees. I’ll provide a possible explanation in my next post.

We found a particularly unusual bark chip at the base of the tree on the left. While it comes from a relatively small branch, the way it was removed may be significant. Over 1/3 of the chip is cylindrical encompassing almost the entire circumference of the limb; it was not pecked off piece by piece; instead, it appears to have been loosened by several blows and then pried free. The bark is hard, suggesting it was tightly attached; it was moist and contained a good deal of frass when found. The piece is very large, approximately 13″ long and nearly 7″ in circumference.

On the return trip, we found a small group of three sweet gum snags, somewhat on the longer dead side. All three had recent to fresh scaling, and there were very large bark slabs at the bases of two of them. These slabs of bark were dense and hard, suggesting that they were tightly adhering when stripped.

We came across a massive relict cypress on the way back. It’s not the first time I’ve seen this tree, but it never fails to take my breath away.

img_2999

~7′ DBH cypress. Dec. 2016. Photo by Phil Vanbergen

On the morning of December 21st, Phil and I went to Sector 1, and Patricia and Steve went to Sector 3. We decided not to deploy a camera on the downed top we had found on the 16th. We have two functioning cameras at the moment, and it seemed more prudent to deploy them on untouched substrates. We didn’t find any new scaling or a substitute target, so we decided to head for Sector 3 where I had a couple of targets in mind.

As we were walking to the car, I got a text from Patricia saying that she and Steve had just had a possible auditory encounter. Steve is a dedicated birder with very good hearing and excellent ear-birding skills. Patricia has limited experience, but she is a retired opera singer with a good general ear. Here are their descriptions of the morning’s events.

***********************************************************************

Steve: At about 9:10 am, Patricia and I were in the bottomland hardwood area in Sector 3. The weather was overcast and cold without any wind – very good conditions to hear bird calls. We had walked southward for about a quarter of a mile in the bottomland area when we had decided to do some DKs. Actually it was Patricia’s idea to do some DKs, and we proceeded to find a small American Holly that was the right size to cut two sticks for knocking.

Patricia: I thought it would be a good location, as I remembered Frank, Steve, Mark and I had done them at the same location a few years back. I remember the fallen tree we all sat on for lunch. Steve had sardines! And where Frank sat down at the base of a tree and started to snore. When I mentioned to Mark that Frank was sleeping, Frank retorted “I’m not asleep”

Steve: The location is one where we could see for a distance fairly well. When we started the DKs, we did not keep up with how many were done or how long we did them, but I think it was for about 10 minutes. We made an effort to keep watch for an incoming IBWO that would be responding to the DKs, but we were probably not as diligent as we could have been. At a point we had engaged in some conversation. I was sitting on a sweetgum log and Patricia standing about six feet away. My right side was facing south. Patricia was talking when all of a sudden I heard what sounded like at least two distinct calls from my right. The calls sounded like textbook calls of the IBWO – a bit like a toy horn was being blown. I know White-breasted and Red-breasted Nuthatch calls very well and what I heard did not sound like either of those birds. I immediately put up my left hand to stop Patricia from talking and pointed with my right hand toward the south. I told her what I had heard while we both strained to hear any more calls. There were no more calls. Also, we did not see the bird. It is highly likely that we did not spend enough time watching and listening for the bird after I had heard it call. It is hard to say how close the bird might have been to our location because I don’t know how far their call can be heard.

Patricia: I think I did about 10 DKs, perhaps 15-30 seconds apart. When I didn’t hear anything interesting,I joined Steve, who was about 20 yards away. We started talking, and I was responding to something he said when his hands went up and his eyes widened. He whispered, “Did you hear that? Kent calls?” I shook my head no. We listened for a while, but probably no longer than 5 minutes.

Steve suggested we do another round of DKs to see if we could call in whatever made the sound again. I asked him to do the next round, as I my hands were stinging and sore; plus I wanted to hear them from someone with more experience. I think that, should someone have an auditory encounter, another person should take their place during a second round of DKs.

I stayed where I was standing when Steve heard the kents but was facing directly south. After 3 or 4 DKs, I heard something similar in cadence, but it had a sharper, crisper quality to it (similar to recorded Campephilus double knocks). It came roughly from the southwest. By the time Steve joined me later, I had convinced myself that it was caused by the logging that we heard going on in the distance, also to the southwest. If I mentioned hearing the DK to Steve, I probably downplayed it, blaming the logging or a falling limb; the winds were very calm at the time, and I didn’t hear any similar sounds from the logging that morning.

I have not spent much time in the field and am reluctant to place too much weight on my observations. I’d much prefer the IBWO (should it be out there) land on my shoulder “Sonny Boy” style and leave behind a fine DNA sample, after I manage to take a series of selfies!

***********************************************************************

Don’t we all . . . or at least that we could call them in like Barred Owls.

img_2953

Barred Owl, iPhone photo by Patricia Johnson

We met up with Patricia and Steve, and Phil set up the cams; one is currently aimed at a sweet gum stub we targeted last year before losing a camera to flooding. There is some fresh woodpecker work, I suspect Hairy, on the stub, so this may be a good  time to target it. The other cam is trained on both a downed sweet gum top and a longer dead snag. Both are within the area where we’ve had multiple possible encounters recently, not far from the heavy concentration of sign found last spring.

Toward the end of the day, Phil went to do an evening stakeout in sector 1; Patricia went with him, while I took Steve a little farther north to show him a couple of the hickory stubs. In this location as well, there were a couple of recently scaled sweet gums in within 20-30 yards of the older hickories, which were similarly about 20-30 yards apart. We also examined one of the hickories Steve photographed in 2013; it was alive at the time. This one had decayed somewhat more rapidly than many of the others I’ve found, but it’s at a lower elevation relative to the nearest water body.

Steve remarked that he’s never seen feeding sign like this anywhere else, and he has spent countless professional hours in bottomland hardwood forests.

Spscaled hickory (2)

Scaled hickory, 2013. Photo by Steve Pagans.

Frank, Phil, and John Williams will be in the search area over the next few days, so there may be another report coming soon, in addition to the post I’m planning on hickories and foraging behavior.


Trip Report December 16-21, 2016, Part 1

On this trip, I was joined by Patricia Johnson (my wife) who was making her first visit to our search area in over two years. Phil Vanbergen was along on Friday, when a classmate of his, Jeremy Irion, spent also spent the day with us. Steve Pagans, retired forester at D’Arbonne National Wildlife Refuge, was very active in our efforts until he was sidelined with back trouble. He too made his first visit in over two years on Tuesday and Wednesday. It’s great to have Steve along for his birding skills and knowledge of this habitat type. Phil returned on Tuesday and Wednesday, and spent Thursday in the woods on his own. Frank Wiley was unable to get out this time around.

Prior to our departure, rain was predicted for three of our planned field days, but as it turned out, the weather was generally tolerable, if cold at times; Saturday was the only day when conditions, high winds and predicted thunderstorms, kept us away. Patricia and I took that day as an opportunity to visit Tensas National Wildlife Refuge (on the site of the Singer Tract) and Bayou Cocodrie National Wildlife Refuge. More on these visits below.

Although I didn’t have any possible encounters (Steve and Patricia’s will be discussed in Part 2), the trip was an incredibly productive one for me. We found a good deal of recent feeding sign. I also took the opportunity to look at over 10 hickories that have been scaled within the last several years. This is the type of work I think is most compelling for ivorybill.

I got what I think are some important new insights and some ideas about how whatever is stripping bark is behaving over time; these merit a separate post that will likely follow Part 2 of the trip report; I also anticipate writing an addendum to the feeding sign page I added recently. I hope these insights can inform our strategies going forward. It’s especially helpful to get fresh perspectives, so I’m grateful to Phil, Steve, and Patricia. Each in their own way helped me think a little more deeply about my observations; a conversation I had with Frank after a long day in the field was similarly helpful.

The groups of images in this post are in “tiled mosaic” format. Clicking on any single image will enable you to scroll through the group and enlarge the individual photographs if you choose to.

We met Phil on the edge of what we call Sector 1 at 6:45 am on the 16th. The weather was cloudy, cold, and windy; later in the day, the thermometer soared to nearly seventy, but the skies remained a wintry gray, less than ideal conditions for finding feeding sign or observing birds. Nevertheless we did find some recent work on both standing and downed sweetgums and on a broken hickory limb, all of this in an area where we’ve found an abundance of scaling every search season. None of this work is in the category I find most compelling; the hickory limb is probably most interesting due to the characteristics of hickory bark and the very large bark chip we found below the limb. Given what we’ve observed on hickory boles, this may be good target tree for later in the season.

The scaling on the downed limb has some features that might point toward Pileated, especially the layered appearance at the lower right and the patchiness of the work on the smaller limb. Conversely, the shredding of the cambium on the stub is consistent with what Edith Kuhn Whitehead told us her father associated with ivorybills.

Phil and I considered aiming a trail cam at the downed limbs but decided the work was not quite interesting enough.

The weather forecast for the 17th was ominous, with winds upwards of 20 mph and thunderstorms predicted for the afternoon. Patricia and I thought we might be able to spend a couple of hours in Sector 1, but when we reached the trailhead we found a truck parked where we were planning to walk in. Given the bad weather and the presence of hunters, we decided to head straight for Tensas, a pilgrimage I’d been wanting to make for some time.

The drive took a couple of hours, and our Wayz app sent us on a couple of roads that dead-ended in bean fields, but we finally made it, only to find the visitor center closed for the weekend.

imgp3885

We took a walk on the boardwalk behind the headquarters and found a dead tree that had been almost completely stripped of bark, large soft slabs of which were lying around the base. I’m posting a photograph to illustrate how difficult it can be to explain what we’re finding to those who haven’t seen it firsthand. I doubt there are ivorybills in Tensas, but if I found this work in our area, I wouldn’t suspect ivorybill. The remaining adhering bark is loose and decaying; the large slabs we found on the ground were soft and pliable. The tree in the background has a little bit of scaling on it too, but it is in an advanced state of decay, and the bark has not been removed from large, contiguous areas.

As we drove around Tensas, we did note occasional instances of high branch scaling, but nothing remotely suggestive. Again I’m again including these examples in hopes of providing more clarity with regard to the kinds of feeding sign I find suggestive for ivorybill; this work doesn’t qualify; it is on very small, longer dead limbs; it does not involve large, contiguous areas; nor does it reach the bole or larger parts of the limbs.

We spent a couple of hours exploring the refuge from the road, stopping at Africa Lake, on the West side of the Tensas River, and then drove Sharkey Road, stopping for a somber moment on the bridge over John’s Bayou. I’m facing south in the picture below; Tanner would have walked north to the core of the home range. There are strips of maturing woods along the banks of the bayou but bean fields to the east and west. Tensas is big, extensively wooded, and an impressive restoration effort is under way, but the visit left me saddened, with a more visceral sense of what was lost when the Singer Tract was logged.

From Tensas, we went to Bayou Cocodrie, a nearly 15,000 acre refuge that’s part of a large, east-central Louisiana potential habitat complex. While the corridors are not uninterrupted, they encompass many thousands of acres of maturing forest, from D’Arbonne and Tensas National Wildlife Refuges to Raccourci Island and Tunica Hills. There’s some connectivity with the Atchafalaya Basin as well. Bayou Cocodrie is fairly isolated and hard to reach (Wayz was unhelpful again); it includes a small (775 acre) stand of old growth hardwoods (the Fisher Tract), and there may be a good deal more surrounding forest that’s suitable for ivorybills. I met a professional hunting guide a couple of years ago, and he claimed to have had an encounter there. We’re planning to visit Bayou Cocodrie and see the Fisher Tract and surrounding areas on my next visit.

Patricia and I were on our own on the 18th, which was a much colder, clearer day after some early morning clouds broke up. We spent the early part of the day in the northeastern part of Sector 1 and didn’t find anything of interest. We went to the scaling concentration in Sector 3 in the latter part of the morning and stayed in the area until about 3 pm.

I didn’t notice any new scaling worth mentioning, but we found a limb that had fallen and broken apart in the storms that had raged through the night before. The scaling had been done before the branch fell, and except for one targeted dig, there was no associated excavation. While some of the bark had loosened, it was tight (impossible to remove without an implement) on the edges. I’ve included several images because they help illustrate the difference between the very extensive scaling we’re finding in our area and what’s common elsewhere (as shown in some of the Tensas photos). Patricia is 5’9″.

Stay tuned for Part 2.