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Trip Report: June 7-11, 2017

This most recent trip was very snakey, meaning I nearly stepped on several – cottonmouths and timber rattlesnakes. In all my years of searching, I’ve seen six rattlers, three on the most recent trip.

Rather than do a day by day log, I’m just going to post the highlights this time. I took few photos, mostly of reptiles.


I made this trip with absolutely no expectations, given the time of year, although I had hopes that one of our target trees might have been hit. As is so often the case, my hopes went unfulfilled, even as my expectations were exceeded.

I was joined by wildlife biologists Tommy Michot and Peggy Shrum for the entire trip. Phil Vanbergen came along on Saturday. Phil has heard Pale-billed Woodpecker double knocks, and Peggy has heard numerous Campephilus DKs while doing fieldwork in South America.

There was no fresh work on the hickories we have targeted, but we are reviewing the trail cam photos nonetheless. We found another hickory that recently lost its top and have targeted it, along with a nearby hickory and a beech, with our remaining trail cam. The cavities discussed in an earlier post are currently obscured by foliage.

We had possible auditory encounters, all knocks, on Thursday, Friday, and Saturday, and while I would label most of what we heard as “weak possibles”, the Thursday knocks were within one of our “hot zones”, not far from where the March recordings were made. The Friday knocks were in a different area, one we visit infrequently. In most instances, these knocks were heard by one or the other of us, but on Friday, we had some instances where two or all three of us heard them. And all of the Friday knocks were heard in the same general area over a couple of hours.

The Saturday knocks were a lot more interesting. Here’s a detailed description:

Tommy, Peggy, Phil, and went to deploy the trail camera. Peggy has heard many Campephilus DKs in South America, and Phil has heard them in Costa Rica. We heard a possible ambient knock (I can’t be sure if it was an SK or DK) while walking; it was quite loud, but we initially dismissed it as a gunshot. About an hour later, after deploying a trail cam, we set up and did a series of Barred Owl playbacks followed by a DK series. I turned off the recorder after about 15 minutes, but we remained in the area, talking quietly. At 28 minutes after the DK series, we heard a loud SK followed by an apparent DK 5-10 seconds later. We considered and ruled out gunshots (absolutely impossible given the context) and tree fall (light winds, no rain since Tuesday, no rustling of leaves or other accompanying sounds, length of the interval between the first single knock and the subsequent double). Both Phil and Peggy thought it was very good for Campephilus. The source of the knocks was close, probably no more than 200-300 yards away.

About three minutes later, Phil and I heard another more distant DK; we both thought it was quite good, but Peggy and Tommy missed it. My recorder was running at this time, but it did not capture the sound.

After discussing it, none of us felt a gunshot was likely for the earlier knock, since there was no other shooting all day; it seemed to have been fairly close; in June, the only hunting in the area is for hogs, and it is infrequent; the road is quite a distance away; and we hadn’t seen another vehicle in the area all week.

I’m looking forward to returning in October and hope to have enough material for a couple of posts before then. I’m also delighted to have Peggy on board as part of the team; she brings a lot to the table. I’m hoping that coming seasons will involve an expanded team and a more concerted effort, so that we can obtain something conclusive or rule out ivorybill. My only regret about this most recent trip is that I didn’t harvest more chanterelles and didn’t start collecting them until our last day in the field. They were everywhere, and they are delicious.

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Singer Tract Area Ivorybills in 1948

Just over a year ago, I quoted at length from a 1949 letter to Tanner from Arthur MacMurray (a former student).  I’m reposting that transcript below and have some additional commentary. Eckelberry’s famous “last” John’s Bayou sighting in April 1944 has become a legend, even though Peterson, writing in 1948, had the lone female remaining at John’s Bayou until December 1946.

John’s Bayou aside, the MacMurray letter suggests that at least three ivorybills remained in the vicinity of the Singer Tract until the end of 1948, although not in the areas that Tanner studied. I read these reports as involving at least three birds because Willett mentioned a pair, whereas Williams and McCallip involve a lone bird. The Williams and Willett reports seem highly credible to me, given that Willett undoubtedly knew ivorybills and MacMurray seems to have trusted Williams’s ability to recognize the species.

I have tried to identify the locations involved. Little Fork Road still exists, south of Little Fork Bayou. It is west of the Tensas, about 10 miles northwest of John’s Bayou. North Lake #1 presented a challenge. The only North Lake I could find in the area is the North Lake Marydale Oilfield, which is in Tensas Parish, about 18 miles south-southwest of John’s Bayou and 20 miles south of Little Fork Road, just outside what is now Buckhorn Wildlife Management Area. While it’s possible that MacMurray (via Willett) was referring to a designation on a lumber company map (H. Baldwin, pers. comm.), it seems reasonable to infer that this is the North Lake referenced in the letter.

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It may be worth noting that as of 1943, a number of relatively small parcels in the vicinity of Little Fork Bayou, including the McCallip property, were not owned by Chicago Mill or Singer. Perhaps these parcels provided at least a temporary refuge, MacMurray’s reference to all he saw having been cut over notwithstanding. Perhaps this hints at how the remaining Singer Tract birds were dispersing or surviving in degraded habitat. Beyond that, there may be little to infer, except that while Eckelberry and the Fought boys’ “last sighting” was valid and makes for a moving story, its lastness is folklore.

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The Singer Tract has been cleaned of all its commercial timber as far as I could gather. No Ivorybills have been seen at John’s Bayou for at least three years, according to a resident who has lived adjacent to it for twenty-two years. ( . . . but he is on the lookout for them and remembers you.) John’s Bayou has a lumber railway passing thru it and passing all the way north to some point due west of Tallullah. The Ivorybills apparently left John’s Bayou soon after the large gum tree which had been their nest tree for several years was lumbered.

Mr. Gus Willett is still the local game warden. I phoned him. He expresses his best regards to you. He says that only one pair of Ivorybills are known to be in the region (seen in late November), having moved to North Lake #1. He says that whatever Ivorybills are left are apparently wandering over much larger areas than formerly. He says that all the old stands of gum tree are being lumbered now or very soon, so he thinks the prognosis for Ivorybills is dark and apt to be very brief. He doesn’t know whether or not Ivorybills have been found elsewhere in Louisiana or elsewhere in Florida in the past few years.

A friend of the gentleman who resides adjacent to John’s Bayou reported that he saw what he thought was an Ivorybill on E.C. McCallip’s property on the Little Fork Road 6 miles south of Waverly on December 17th of 1948. So Dot and I spent the night in Tallullah and visited McCallip’s place (minus boots – It was very muddy) All the land we saw looked cut over. There were lots of woodpeckers. Saw 5 Pileateds but none of their cousins. I questioned Mr. Ward Williams (address: Del Hi, Route 1, Box 184-A, Madison Parish, Louisiana) who recognizes Ivorybills and distinguishes between them and the “native” (pileated) peckerwoods. He claims to have seen an Ivory Bill there in November. He regards them as nesting residents and thinks he can find a nest of them there without very much hunting. I left my address, and he intends to write next time he sees a bird. He and his visitors were aware of Ivorybills having been at the Sharkey place adjacent (or in) to Singer Tract.

Dot and I found it expedient under the murky circumstances to proceed on to New Orleans for Xmas day.

. . .

Wish I had more optimistic new regarding the what kind of future we dealt the big-woods peckerwood.

Best Regards,

Arthur

 


Trip Report: April 26-May 1, 2017

I returned to the search area last week and spent as much time as I could in the field. The trip was generally uneventful, and conditions – strong winds, rain, and high water – limited my field time. Woodpeckers are getting quieter generally; full leaf out, heat (temperatures in the high 80s on the 26th, 27th, and 28th), and abundant mosquitoes make things even more difficult at this time of year; nevertheless, I’m planning one more trip before summer.

On the 26th, I hiked to hickory stub that currently has two cameras trained on it, as one camera needed securing. There were no signs of woodpecker activity on the stub. This beautiful Great Egret in a beautiful spot was a highlight. There were Little Blue Herons in the vicinity too, but I couldn’t get a clear shot, too much mud and intervening vegetation.

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On the 27th, I arrived at the “listening point” (where the March recordings were made) shortly after sunrise. I opted to sit quietly, rather than doing playback or ADKs. I did not see or hear anything.

I met up with Steve Pagans at around 10 am. Since water levels were low, we were able to get closer to the snag with the cavity that I found last month. I spotted a second cavity higher on the stub, on the opposite side. IMGP4571 (1)

These cavities are large, similar in size, shape, and unusual appearance. While I suspect they are no longer active roosts, we will put a camera on the snag in June, if it’s feasible to do so. The nest John Dennis found in Cuba appeared to have two entrance holes, although Dennis thought one might be too small.

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On the hike out, I spotted this wolf spider with her young on her back.

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On the 29th, Steve and I visited one of the less accessible parts of the search area. It is an impressive patch of forest, with some oaks and sweet gums approaching or surpassing 5′ DBH. The sweet gum below is probably the largest single trunked gum we’ve found.

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Reminiscent of the Singer Tract.

Predicted wind speeds were 15-20 mph, and the gusts were undoubtedly stronger, so birds were not very active. The gusts were often unnerving, and a couple of large limbs fell, uncomfortably close to us, while we were stopped for lunch.

The forecast for the 30th was for even stronger winds, with thunderstorms in the afternoon. We decided to play it safe and stay out of the woods. Steve went home, and I spent part of the day driving scouting a large patch of nearby forest by car, but I wasn’t able to reach the bottomland area that had intrigued me on Google Earth.

The rains didn’t arrive until evening, but they were very heavy, with 3-4″ overnight. Thunderstorms continued until mid-morning on the 1st, so I didn’t venture out until about 10:30. Conditions were cool and cloudy, and everything was soaking wet. My movements were limited by high water levels; these continued to rise during the four hours I spent in the field. Avian activity was again minimal. Coming across this rattlesnake, the third or fourth I’ve found over the years, was the day’s highlight.

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On May 2nd, my last field day, I spent the early morning trying to get to the hickory stub and trail cams. Water levels were too high, so I returned to my car and drove to a more accessible location. While I have been concentrating on it less this season, there have been a number of possible contacts in this area, and we have found abundant sweet gum scaling there every year. As has been discussed in several recent posts, classic, ‘Tanneresque’ high branch scaling on freshly dead sweet gums is not necessarily inconsistent with Pileated Woodpecker.

Still, I found some very dramatic work on the dead fork of a dying gum. Phil and I first found this tree in February, but most of the scaling has taken place since then. Of particular note were the enormous bark chips found at the base, again all removed since the end of January. My hat, which is shown for scale, is 12.5″ x 12″. Note that this scaling involves some of the largest limbs. Since some gum balls are still attached to the dead limbs, I think it’s safe to assume that the bark remains relatively tight; the scaling also looks generally clean, something that I find suggestive of ivorybill. To the best of my recollection, the bark chips are the largest I’ve ever found from sweet gum limbs.

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Later that morning, I found a mildly intriguing cavity in a small sweet gum (~18″ DBH). While it’s almost surely PIWO, I’m including it because the shape and skewed angle are somewhat interesting and also to illustrate that even smaller trees can host substantial cavities. The original image was badly backlit, so I’ve brightened it and rendered it in black and white to make the cavity easier to see. Referencing Dennis again, he estimated the diameter of his Cuban nest tree at 12″. While DNA evidence suggests the Cuban IBWO is/was a different species, more closely related to the Imperial than to the US IBWO, the conditions under which Dennis found a breeding pair seem relevant to the survival of the North American species, and the ‘old growth specialist’ caricature:

There was a sprinkling of deciduous trees, some quite large. Although this region had been heavily logged and burned over as well, growth was quite luxuriant in spots. A watercourse, as well as the generally rugged terrain, had prevented a clean sweep of all the timber. The pine  trees, on the whole, were limited to less than five inches in diameter.

There may be more on this in an upcoming post.

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Project Coyote’s Future and Two Trip Reports from March

The audio obtained in March took precedence over the trip reports and a few other things I’ve been meaning to address for some time. They’re worth a listen if you haven’t done so already.

Longtime readers of the blog have probably noticed the donate button and the advertising that now appears on the site. Project Coyote has been mostly self-funded from the start, except for a few donations from anonymous individuals and the Rapides Wildlife Association. Some used equipment has been passed on to us by other groups of searchers. I’ve long believed that we’d be able to document ivorybill presence (or go a long way toward ruling it out) with more consistent coverage in the area and a relatively modest budget.

At this point, remote recording units and a couple of additional cameras are at the top of the wish list. Ultimately, I’d love to be able to cover costs for our core group and to provide funding for one or two people to be in the area steadily, at least during February, March, and April. I can dream . . . Anyway, your contributions can help make some of this possible.

Before Frank’s passing, I had decided to ‘retire’ from active searching after this season, for a number of reasons – the sense that I had nothing further to say about feeding sign and the fact that I did not personally see or hear anything strongly suggestive of ivorybill presence in the 2015-2016 season among them. The lack of recent work on hickories was particularly discouraging.

Things started to change when Frank was in the hospital. It became clear that our search was important not only to Frank but also to his family and friends. A number of long-time, mostly quiet, enthusiasts and supporters (including Matt Courtman who had visited the area with Frank some years ago) reached out and encouraged me to continue and even to intensify the effort.

Shortly thereafter, Phil Vanbergen found some recent scaling of the kind that I think is diagnostic for ivorybill on two hickories, though it turned out the work was not as fresh as initially suspected. The trail cam capture of a PIWO removing a strip of bark from one of the trees led me to begin my first March trip in a somewhat pessimistic frame of mind. It didn’t take long for that to change – another ride on what I’ve taken to calling the IBWO-llercoaster.

I arrived in the search area on March 9 and met up with two out-of-state birders with whom Frank and I had been corresponding for some time. I showed them around the search area. They were impressed by the habitat, but we did not see or hear anything significant. On the morning of the 10th, I sent an email to some of the team expressing my frustration over not having had a “compelling recent encounter” and stating that my possible October sighting didn’t meet that standard (even now, I don’t think it compares to the March recordings.)

I was on my own on the 10th and had a slightly less discouraging day; I got my first opportunity to examine the scaled hickories Phil had found. This strengthened my suspicion that the recent PIWO work was “wake feeding”.  Later, I met Matt for dinner and a strategy session.

Everything changed on the 11th. In addition to satisfying myself that the extensive scaling on the hickories was at least several months old and that the recent Pileated activity was likely secondary scaling (based primarily on the small bark chips); over the course of the day, we deployed three of our four trail cameras.

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Even more importantly, we had auditory encounters in both the morning and the afternoon. Here is my write up from that day, with a few redactions.

At about 10:15, we were in close proximity to where we’ve had several possible contacts, most recently when I was out with Frank in October. We’d just deployed a second trail cam, and Matt had gone about 50 yards north and west of Phil and me. He texted and asked if he could do some DKs (he’s using two wooden blocks that he knocks together.) He did several, no particular pattern, mixed ASKs in with the ADKs.

I did not take notes, and my memory of the exact sequence is weak, but I heard 5-6 DKs and SKs coming from the east in response. If I remember correctly, there was at least some interplay between the ADKs and the DKs, meaning that there were a couple, and then a pause, then Matt DK’ed and there were replies. Matt said he heard 4-5, and I think Phil said he heard 3-4.

Whether or not I’m misremembering, it was far and away the most compelling series of responses I’ve ever heard, and I’ve done hundreds of ADK sessions. **** this was similar to what you encountered on your first trip, in the same general vicinity, but a lot more dramatic. In addition, there was no ambient foraging, and other than the responses, all we got was one PIWO drum from a different direction. Phil said that one of the DKs was very similar to the Pale-billed DKs he heard in Costa Rica last summer. 

For the kents, we were at a different location a few miles away; the time was approximately 2:45 pm. Phil and Matt heard a number of calls, of which I only heard two. Of the two I heard, the first was on the low-pitched side, I’d say close to the pitch of the what Tanner called “conversational” calls on the Singer Tract recordings or what Frank and I called the “wonka wonkas”; it had a trumpet-like quality, maybe more than I’d expect for an IBWO, but still in the ballpark. The second was higher pitched and more tooty/reedy, very close to the Singer Tract recordings. The wind was dead calm for the second call, so it was not a tree squeak. In both cases, the calls came from the East.

. . . 

So there we are. Quite a day. Now, if we could only find out what’s making the sounds and what’s knocking the bark off the hickories at the outset.

For those who missed it, here’s Phil’s recording of two of those calls – headphones or good speakers recommended. We did not record the knocks we heard in the morning.

On the 12th, Steve Pagans, Matt, and I returned to the location and heard 1 ambient DK and 2 SKs, at approximately 1:55 pm.

These sounds came from roughly the same direction as the calls we’d heard the day before. The possible DK was not as loud as the SKs, or as yesterday’s knocks, but it was distinct. Matt did some ADKs. There was a Red-bellied Woodpecker foraging to the south of the direction of the knocks. Matt’s ADKs seemed to induce it to bang more frequently and forcefully, but we didn’t hear any distinctly IBWO sounding knocks in response. Steve and I heard a single possible kent from the same direction as the possible SKs and DK. It was faint. Steve heard it better than I did and thought it was good; Matt didn’t hear it all. This was probably due to how we were positioned in terms of proximity to the sound.

Under normal circumstances I’d label this episode as a fairly weak possible, marginally worthy of mention on the blog. But given the location, it seems more significant.

The 13th was also eventful. Matt and I opted to return to the area where we’d heard the knocks on the morning of the 11th and give the other location a rest. Here’s my write up of the morning’s possible auditory encounter.

We decided to do a mix of playback and DKs at 9:40 AM. I did about a minute and a half of playback, using the iBird app (3 rounds – 28 seconds of Kents, “conversational” calls, and tapping). Matt followed with perhaps a minute of knocking wood blocks together. Over the course of the following five minutes, we had several knocks. Initially, Matt heard a single that I think I missed. It was followed by a very loud knock coming from the East. It was VERY loud and clear, what Frank would have described as some banging on a tree with a baseball bat. Shortly thereafter, another sound came from my left, roughly north of us. Matt heard it as a single, but I heard it as a double, with the second to my ears perhaps the closest thing to what Tanner described as an echo of the first I’ve ever heard. After that, we heard another loud single roughly from the southwest. The last was more distant and somewhat less striking.

The first single knock and the one I heard as a double were astonishing. There’s no doubt in my mind or his that these were neither mechanical sounds nor foraging. I am kicking myself hard for not having my recorder running; I’ve gotten too jaded about auditory encounters, and it’s a little tough to manage both recording and generating sounds.

A little later, I found a dying chestnut oak with some mildly intriguing feeding sign. There were some huge, thick bark chips on the ground and this, more than the appearance of the work on the tree, struck me as potentially suggestive; this is the first interesting work I’ve found on an oak in several years.

Matt and I returned to this location on the morning of the 14th. Matt did ADK series on the half hour until shortly before noon. It was a cold and windy morning, uncomfortably so. We heard nothing of interest.

On the 15th, I headed for New Orleans and my flight the following morning. Phil and Matt returned to the woods and captured numerous calls between 7 and 11 am. When I heard the recordings I cleared the decks and made arrangements to return as soon as I possibly could.

Patricia and I were back in the woods by lunchtime on the 23rd. Louis Shackleton – a good friend, professional photographer, and birder who happened to be in Louisiana – joined us on the 24th. We didn’t see or hear anything of interest and left early ahead of predicted heavy rains.

At shortly after 11:00 am on the 25th, Patricia and I heard some possible double knocks in apparent response to some very aggressive knocking on my part; two of these knocks came from roughly north and one from the east (the same direction from which the March 15th calls were coming).  I’m still reviewing the audio from this trip and may have additional material to post in the future.

I went out alone on the 26th, returning to the same vicinity, and did not see or hear anything interesting.

We were rained out on the 27th. On the 28th, I found a large cavity not far from where the calls were recorded. It does not appear to be fresh enough to be a recent nest, but we plan to target it with a trail cam in the event that it’s being used as a roost. This find illustrates how difficult it is to spot cavities in our search area – six people had spent the better part of multiple days in the immediate vicinity before I noticed it, and the snag is in plain view.

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More storms came through on the night of the 28th, and the next morning Patricia and I decided to take a break from the “hot zone” and instead visited the area where Phil found the recently scaled hickories and where Matt, Phil, and I had heard knocks on the 11th and 13th. We found that one of Phil’s scaled hickories had lost its top, which gave me a chance to examine one of the scaled areas up close. As expected, the wood was somewhat punky, and and the bark was fairly easy to remove by hand.

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We also discovered that the top of one of our target hickories had been blown off. The tree shows signs of beetle infestation, which gives us reason to hope that it will be visited by woodpeckers before too long.

It was interesting to get a close look at this freshly fallen top and examine how hickory bark separates from the trunk under these circumstances. While it seems to come free fairly easily in very large strips, the bark is extraordinarily tough and strong. When fresh, it’s flexible but very hard to break; doing so requires twisting, and it won’t fracture. Within about 48 hours the piece I collected had dried out and become surprisingly hard. This further reinforced my view that Pileated Woodpeckers are not anatomically equipped to scale large chunks of bark from live or freshly dead hickories.

It was a beautiful day in the woods, and some of the other highlights included recently hatched Wood Ducklings, a posing Yellow-crowned Night Heron, and the first ‘gator (a small one) I’ve ever seen in the area.

The next morning, I returned and redeployed a second camera, which had been trained on another nearby hickory, to the one with the downed top so that we can cover the entire stub.

We spent the morning of the 31st in the area where the calls were recorded before catching an afternoon flight. We did not note any interesting sounds while in the field, but after listening through Patricia’s recordings, I noted the possible double knock discussed in the previous post.

I’m planning two more trips before summer. I anticipate that we’ll have all cams deployed and have high hopes for the hickory stub.

Meanwhile, I thought I’d throw in some additional images that may help to convey what a special and magnificent place this is.

 

 

 


Possible Double Knock in Reaction to a Barred Owl

For a slight change of pace, I’m posting this possible double knock in reaction to a calling Barred Owl that Patricia Johnson captured at 8:40 AM on March 29th, within 50 yards of where the calls were recorded on March 11 and 15. I’m posting this particular double knock because the context may give it added significance – the apparent reaction to the Barred Owl call and the fact that there was no temporally proximate ambient foraging.

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I’m somewhat hesitant about posting recordings of knocks, especially those not noted in the field, for a number of reasons: our field tests have revealed that in deep woods, ADKs can sound like single knocks at a couple of hundred yards; it’s also not uncommon for observers to disagree about whether knocks heard in the field are singles or doubles, and the same is sometimes true about recordings. In addition, most of the interesting knocks captured last month are faint on the sonograms, and in the case of the knock posted below, the second knock does not show.

Nevertheless, this double knock appears to be in the right range for Campephilus in terms of the interval and the pattern – louder first knock followed by a softer second one.

Edited to add: Another reviewer has suggested that the knocks are “too slow”.

I’m two trip reports behind and hope to get to them before returning to Louisiana.


More Recordings from March 15: Approximately Three Hours of Kent-like Calls and Analysis

On March 15, Phil Vanbergen and Matt Courtman recorded numerous kent-like calls at the same location where we heard several calls on March 11 and 12. Phil was able to record two of the March 11 calls. That capture is included in the post, along with Phil’s audio from the morning of the 15th. I heard two of the calls on the 11th; the second one in particular struck me as being consistent with the Singer Tract recordings; the first seemed a little low pitched to my ears, an observation that’s captured on the recording. Steve Pagans and I heard several calls on the 12th, but these were not recorded.

Matt obtained nearly three hours of audio, and to my ears the sounds are coming from 2-4 distinct sources; I had the same impression after listening to some of Phil’s clips. I have now listened all the way through Matt’s recordings several times and will share my analysis below. Matt and Phil are likely to weigh in later with their perspectives. I also have a couple of trip reports pending, so there should be a lot of activity on the blog in coming weeks.

To start with, I counted over 200 kent-like calls in all.

On the long clips posted here, I’ve edited out all of Matt’s ADK (anthropogenic double knock) series, which he did on the half hour. The knocks are very loud, as can be heard from the one trailing sound I’ve left in. I also snipped out several minutes of conversation between Phil and Matt. The ADKs seem to have led to more frequent calling and may have provoked some double knocks, something we may address in a future post.

Edited to add: On further review, there does not appear be a correlation between ADKs and more frequent calling. Clips like the one posted below can be deceptive. One kent-like call that overlaps with a knock has been deleted. There is also one possible knock in response. Caution, ADKs have not been completely spliced out, and they are loud. See bottom of page for brief clip and sonogram.*

Between 6:12 and 6:25 on the last long recording made that morning, there are five calls of differing durations and volumes, followed by what may be a double knock. Similarly, at the end of the full clip, starting at 14:14, 3 calls are bracketed by some potentially interesting knocks, 2 before and 1 or 2 after.

The first four clips below are shorter, amplified extracts on which the calls can be heard easily.

The first two of these are extracted from the final segment described above and include the interesting, tooting sounds and possible knocks.

The third clip includes multiple calls over 2 minutes and nine seconds, along with a wide variety of other sounds.

The fourth is four minutes long (pardon the airplane noise) and should provide additional context while also revealing some of the variations among the calls.

For those, like me, who don’t have professional sonogram software, I recommend using Sonic Visualizer – an easy to use, free program that enables you to watch the sonogram as you listen.

And for those who are unfamiliar with avian bioacoustics, this is a great place to start. I’m on a very steep learning curve myself and am prepared to stand corrected about any misstatements in this post.

Many of the sounds are audible on built-in computer speakers, but playback through headphones, earbuds, or external speakers is highly recommended.

 

I think these calls were likely made by Ivory-billed Woodpeckers. My perspective is based in part on the fact that I have spent all or part of nearly 40 days in close proximity to where the calls were recorded, starting in 2014. A considerable amount of this time was spent sitting quietly, and the total person hours spent in the area is well into the hundreds. We have had occasional kent-like calls, possible double knocks, and possible sightings over the years, but nothing approaching what transpired on the 15th.

Matt spent the morning of the 16th in the same location and did not hear any of the sounds, and Patricia and I spent 4 mornings and one afternoon there between the 23rd and 31st and heard no similar calls. I think this militates strongly against the idea that the source of the sounds is a common resident of the area.

Three alternative hypotheses have been suggested.

On the morning of the 15th, Phil proposed that the sounds might be tree squeaks. There appear to be multiple tree squeaks on the recording, some with similar pitches, but they bear little resemblance to the kent-like calls on the sonogram or to the ear. In addition, the calls sometimes come singly, sometimes in groups, and they vary in pitch, volume, and duration and seem to occur independent of wind velocity (on the 11th we noted that there was no wind.)

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Sonogram of first clip, showing apparent tree squeaks before and and immediately after two kent-like calls – the stacked horizontal lines right of center.

The first sound, at just after 4 seconds on the second clip, seems ambiguous. The sonogram is somewhat similar to the kent-like sounds, but the duration is very short, and it has a creaky quality. It’s also associated with the two creaky sounds that follow. These can be heard frequently over the course of the morning, and their appearance on the sonogram is nearly uniform.

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Sonogram of second clip showing tree squeaks.

One reviewer proposed Wild Turkey and Blue Jay as possible sources. I think turkey can be ruled out due to the absence of other turkey-like sounds associated with these very persistent calls.

Blue Jay strikes me as a more plausible alternative. Blue Jays can be heard at numerous times on Matt’s recordings. And Blue Jays are known to make kent-like calls, some of them very similar to known Ivory-billed Woodpecker sounds. This is likely not mimicry, since the most similar recorded calls I know of were obtained in upstate New York. The recordist noted the similarity. On the sonogram, the resemblance between these calls and either known Ivory-billed Woodpecker sounds or Matt’s recording is not as strong as it might seem to the ear. While they share a strong third partial, the Blue Jay fundamental is higher and some of the higher partials are considerably stronger.

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Kent-like, suspected Ivory-billed Woodpecker calls recorded by Matt Courtman on March 15, 2017. Note the relatively strong base frequency and 3rd partial, and weak 2nd, 4th, 5th, and 6ths.

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Kent-like Blue Jay calls. Note the relatively weak fundamental and strong second through fifth partials.

It’s also important to note that on the Cornell Blue Jay recording, the kent-like calls are intermixed with typical Blue Jay vocalizations. Over the three hours of Matt’s recording, kent-like calls occur during periods when Blue Jays are vocalizing and during periods when Blue Jays are silent.

Some of the kent-like calls have harmonics consistent with Cornell’s recorded playbacks of Singer Tract calls at 145 meters. Many are lower in pitch. Most have a considerably longer duration, although to my untrained eye/ear, some seem close to the 80-100 ms duration on the Cornell recording. More on duration below.

On March 28, I did some playback of Singer Tract calls using an iPhone and a bluetooth speaker. Patricia recorded them on a Roland Edirol R09HR digital recorder. I’m including the recording and the sonogram for comparison. Like Matt’s recordings, the second partial is strong throughout, and the 1st, 3rd, and 4th appear to be weaker than for the Blue Jay shown above.

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At various points, Phil also experimented with doing playback, using calls recorded in 2010 at the old Project Coyote site. (He also played back several other species – Red-bellied, Golden-fronted, and, possibly, Gila Woodpecker to gauge Red-bellied response, and Eastern Towhee out of personal interest.) Examples of putative ivorybill playbacks can be heard over the first 3 minutes of the fourth long clip posted above and also during the first part of the fifth. These sounds are longer but similar in tonal quality to the lower pitched calls. Their harmonic structure is different, however, with a fundamental at around 800 hz, a second partial at around 1600, and a fairly strong higher partial at approximately 5000 hz., and should be readily identifiable on the sonogram.

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Higher pitched playback calls, at middle left and far right.

Phil’s playbacks do not seem to have provoked any kent-like replies. Blue Jays can be heard during the same time frame, but it’s not immediately apparent whether the recorded Blue Jay calls are responses or merely contemporaneous vocalizations. This segment includes some Blue Jay vocalizations.

With regard to Blue Jays and the numerous kent like calls heard from March 11, 12, and 15: to reiterate, many hours have been spent in this vicinity, with close attention being paid to kent-like sounds. These are heard infrequently and never before in such quantity or over such an extended period. If Blue Jays in the area were making these sounds, we almost certainly would have heard and recorded many of them over the years. In addition, both Steve Pagans and Matt Courtman are experienced and skilled ear birders and neither thinks these are Blue Jay calls.

It’s also worth pointing out that another potential confusion call can be heard on the recordings – White-breasted Nuthatch. The sound is similar but much weaker, as should be clear from the amplified March 15 excerpt. On the sonogram, just below the amplified recording, the calls show up very faintly, with dominant frequencies of around 2200-2400 hz and a relatively strong partial at 1700-1800.

 

 

I encourage people to listen through and draw their own conclusions. Input from those with expertise is welcome.

While I can’t say if any of these calls are a perfect match for the Allen and Kellogg recordings (some may be), many of them are close on the sonogram and similar to the ear. It’s important to bear in mind that the Singer Tract birds were likely agitated when those recordings were made, even though Tanner described some them as being good examples of kents. It’s also important to read Tanner’s descriptions carefully, though as is so often the case, his writing can be opaque. Perhaps his most important observation was that “all of the notes have the same nasal, trumpet-like quality.”

According to Tanner, “The notes of the nuthatches are the only bird calls I know that sound like the voice of an ivorybill; the Ivory-bill’s calls are much longer and pitched higher than the calls of a White-breasted Nuthatch, are more in the range of a Red-breasted Nuthatch.” (Emphasis added.) By contrast, Hasbrouck, writing in the 1890’s, described it as being “exactly like the note of the White-breasted Nuthatch” only much louder and stronger.

Tanner’s reference to Red-breasted Nuthatches has always confused me. I’m very much in Hasbrouck’s camp; I think the Singer Tract kents sound far more akin to White-breasted than Red-breasted Nuthatch. Either way, most of the Allen and Kellogg kents are lower pitched than typical White-breasted Nuthatch calls, as are the ones on Matt’s recording. In addition, the Allen and Kellogg kents seem to be of similar in duration to typical nuthatch calls, rather than longer or “much longer”. This too suggests that they are not typical but are more rapid and perhaps higher pitched due to agitation. Tanner wrote further, “[t]he kent note, given in monotone or infrequently, is the ordinary call note. When the bird is disturbed, the pitch of the kent rises, and it is repeated more rapidly, frequently doubled, kent-kent, with the second note lower. The prolonged and slurring, kient-kient-kient call I always heard when two or more birds were together.” This call was never recorded.

According to Allen and Kellogg, “kenting varied a great deal” and a male bird called “loudly and deliberately”, again suggesting that many calls were of longer duration than those on the recording. Tanner’s notes also point to this variability. At one point, he wrote of “1 and 2 syllable yaps”; he has the Mack’s Bayou bird (whose voice he claimed he could recognize) making a “kient-kient” and also transliterated calls with “keent keent” and “yeenh yeenh” (Bales). These renderings all suggest a more drawn out call than those on the Allen and Kellogg recordings. George Miksch Sutton described the Singer Tract birds’ calls as, “strange, bleat like, not quite sharp enough for a woodpecker’s cry. It was slightly nasal in quality and it sounded to me like ‘Gip!’, with a hard g“. Sutton’s description also suggests that many kents had a fairly long duration.

Edited to add: similarly, several observers (Audubon, Beyer, Hoyt)  described ivorybill calls as “plaintive”; this too seems to imply calls of longer duration than what’s heard on the Singer Tract recordings.

Given the resemblance to the Singer Tract recordings and the lack of plausible alternatives, I posit that these calls are at worst highly suggestive of Ivory-billed Woodpecker.

*Possible knock and kent-like calls temporally associated with ADK series. Caution remnant ADKs are loud.

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Wake Feeding on a Hickory?

This is my 100th post on the blog. It has been on hold for a while due to the new developments. There’s another coming soon with more discussion of recent events and the audio Matt obtained with numerous kent-like calls. I’m now even more firmly convinced that IBWOs were the source of those calls, but that’s a topic for the future.

On the weekend of March 4-5, Phil Vanbergen visited the search area and changed out the card on our deployed trail cam. He found that Pileateds had hit the target tree, scaling a single and large strip of bark during one of several visits. The raw sequence and a slowed version by Steve Pagans are immediately below. Phil also found a nearby hickory that had been extensively scaled and some fresh bark chips at the base. Footage of that tree is also below.

When I was in the search area earlier this month, I scrutinized both these trees quite closely, and it appears that the extensive scaling was not recent. Moreover, we did not pass near enough to have seen the scaling when we were in the vicinity in December.

The first of these trees could not be approached on foot, but no large chips were visible at the base, based on careful examination through binoculars. In addition, the strip of bark removed by the Pileated appears to have been exposed on three sides by whatever did the initial scaling. Nevertheless, it took the PIWO over a minute to remove this compromised bark strip.

The chips at the base of the second were either fairly long strips or small chips, many of which had adhering and punky sapwood (first set of images). This contrasts with large chips found at the bases of recently scaled hickories (second set of images).

I now suspect the scaling on these two trees was done no later than early fall of 2016 and quite possibly in late spring, based in part on what we know about the life cycle of the beetles that appear to have been the initial prey species. As discussed in my post on hickory bark, I think this initial work is beyond the physical capacity of Pileated Woodpeckers.

As I was preparing this blog post, Phil asked to see my notes on Tanner’s field notes, and I ran across an observation about which I had forgotten: Tanner observed IBWOs on a partially dead sweet gum, scaling bark in chunks from dollar to hand sized. Shortly after they left a pileated arrived and started knocking off bark. But, also did a little digging. While other scaled hickories monitored for months have shown no signs of subsequent visits by Pileated Woodpeckers, I suspect that what transpired with these two is what Jon Young, author of the outstanding What the Robin Knows calls “wake feeding”, a reference to seabirds following boats for the food they churn up or throw overboard, although the concept applies in a variety of circumstances. This behavior might help to account for the abundance of scaling in our search area relative to other locations in the southeast.

We’re currently targeting three hickories that have multiple old wounds, in fairly close proximity to trees of that species that have been scaled in the past. A fourth tree we had planned to target has fallen. I hope to deploy a fourth trail cam on a wounded or dying hickory in April. This is a very long shot, given the number of hickories in the area and our limited equipment and resources, but it still seems worth a try

 

 

 

 

 

 

 

Pileated Hickory Bark Snip