Matt Courtman Records Three Kent Like Calls – March 19, 2018

Matt spent several days in the search area after my departure. On the afternoon of March 19, he staked out a fresh cavity approximately .25 mile from a location where I recorded a double knock in apparent reaction to an ADK in 2014 and where we captured some intriguing trail cam images. This is about a mile from where Matt and Phil recorded numerous kent-like calls last year.

After more than two weeks of steady presence in the area, and no possible contacts, Matt heard and captured one distinct kent-like call a few minutes after sunset. On reviewing the audio, I found two additional calls about 16 minutes earlier on the recording. There’s also a very faint possible call that comes approximately 2 minutes and 35 seconds before the most distinct one; it’s so faint that I’ve opted not to extract and include it here. Before providing some commentary, Here’s Matt’s description of his experience and observations:

While on the stakeout described above, I began recording at 6:51 p.m., exactly thirty minutes prior to official sunset for that date and location of 7:21 p.m. For the four days prior to this one, I had been keeping notes on “last of the day” woodpecker sounds. Small sample size, but the woodpeckers had consistently gone silent at six to four minutes prior to official sunset on each preceding day. Falling into the trap of unwarranted speculation, I noted with some sadness that sunset had passed without any intriguing sounds.

The mosquitoes on the evening in question were particularly persistent.  Based on my observation (of a whole four days . . . and involving species other than ivorybills), I almost stopped recording at sunset so I could retreat from the mosquitoes. Honestly, had I not been hearing great coyote howls just after sunset,I probably would have closed up shop for the day . . . but I wanted to record the coyotes.
Almost five minutes after sunset (the 35:52 mark of my recording), I heard a single kent-like call that sounded very much like the ones that we had heard the previous March. The sound seemed to have come from between 80 and 120 yards north/northeast of my position. I continued to record until last effective light, but heard no more similar sounds.*

The following clip runs approximately 1 minute and 45 seconds (to give a sense of the ambient sounds and conditions); the kent-like call comes at 1:36.  

Here is a much shorter, amplified extract. The call should be easy to hear.

The sonogram suggests that the call has a fundamental frequency somewhere between 515 and 550 hz. There’s a strong second partial and a weaker third partial (the horizontal lines to the right of center). While the sonogram is not a perfect match for last year’s recordings (or the Singer Tract recordings for that matter), my ears and my common sense tell me that the source of the calls is the same. While the frequency is slightly lower than most of the calls recorded by Hill et al. on the Choctawhatchee, the structure is very similar. (See figures E and F.)

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Kent-like call recorded March 19, 2018

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Kent-like calls (longer horizontal lines) and tree squeaks recorded March 15, 2017

The two additional calls I found are very faint and presumably more distant. I was not able to tease out a sonogram with my software, even with a lot of amplification. The calls may be hard to hear without headphones, so listen carefully. The first clip is unamplified, and the second is pushed as far as was practical.

Bob Ford had the following to say about the first call (heard by Matt in the field):

“I spent a little more time on this one than I usually do . . . . I don’t do the sonogram analysis work myself but instead listen, compare to other known/recorded sounds, use my field experience etc.

I cannot think of a single thing that would make this sound other than ivory-bill. For me, it’s easy to dismiss the usual suspects like Blue Jay or tree squeaks etc. I fall back to turkey and wood duck. I’ve heard both species make sounds I never knew were possible from those animals. But in this case, even stretching, I can’t make it into turkey or wood duck. The sound is too robust, too “direct” (hard to explain, maybe I mean punctuated?), it’s a single sound (my experience turkey and wood duck continue even if its same sound). It’s not artificial, I believe it came from an animal. I agree, this is about as hot as it gets lead-wise.”

As I pointed out to Bob and the rest of the team, Matt’s call and the ones recorded last year have frequencies and structures that are closer to geese than some of the other confusion species, though I’m convinced that none of the calls we’ve recorded came from geese. These Canada Goose sonograms illustrate the similarity. Jackson, pp. 179-180, also notes the similarity between IBWO sounds and those made by geese.

Cornell’s criteria call for fundamental frequencies between 580 and 780 hz. (the frequency of the kents on the Singer Tract recordings). As already noted, Matt’s sound is somewhat lower pitched, but not outside the capacity of an Ivory-billed Woodpecker. The calls on the Singer Tract recordings that Frank and I described as the “wonka-wonkas”, examples starting at around 3:14, are both goose like and have lower fundamental frequencies.

It’s also worth reiterating that the Singer Tract birds were obviously agitated when those recordings were made, and as Tanner put it: ” . . . the kent note given in monotone and slowly 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. (p. 62, emphasis added.)

Rob Tymstra, an accomplished Canadian birder and IBWO searcher, visited the search area a couple of weeks later, and on April 5, he reported the following from a location a few miles south of Matt’s capture:

“. . .at 11:55 am yesterday, I heard one clear kent-like note about 50-100 yards north of the bridge. I noted the pitch of the sound (using my ukulele) and compared it later to the soundclip Mark sent me a few days ago. The quality of the sound is similar but the pitch of my sound was about a whole note higher than yours. I didn’t hear or see anything unusual after that. I can’t say that it sounded like an ivorybill but it’s certainly a sound I’d never heard before (and I know most of the birdsongs).”

A whole note higher would likely place the fundamental frequency at the low end of Cornell’s range.

I’m personally convinced these calls and the calls recorded last year came from Ivory-billed Woodpeckers. It’s also my view that the recordings Matt and Phil have made are among the strongest evidence for the ivorybill’s persistence obtained to date.

I’m more puzzled by the difference between last year, when birds were calling very actively on at least one day, and it appeared that the sounds had at least two and possibly as many as four sources, and this year when calls have been so few and far between. I can’t help but wonder whether the difference might be due to nesting success last year and failure this year. Pure speculation on my part, but perhaps we’re getting close to resolving some of the mysteries.

If the sounds Matt captured last month were Ivory-billed Woodpecker calls, it seems likely that he was in the vicinity of a roost; however, Matt returned on the morning of March 21 and did not hear anything. (There was lots of avian and woodpecker activity.) No suggestive sounds were apparent on my review of that morning’s recording, so if there is a roost in the area, it seems unlikely that it was used on the night of the 20th. Whatever the case, the location is very short walk from the road, and I plan to devote several mornings and evenings to sitting in the area with recording device running and camera at the ready.

Edited to add: When Matt and I first discussed the call, I remembered that Don Eckelberry’s account and his description of the Singer Tract ivorybill calling around sunset. I’m grateful to Houston, of IBWO.net who was reminded of it too and sent me Eckelberry’s exact words:

. . . At 7:20, after I had finished all my notes and we were about to leave, she popped out and raced up the trunk to its broken top where, bathed in rich orange light of the setting sun, she alternately preened and jerked her head about in a peculiar angular way, quite unlike the motions of any other woodpecker I knew. I was tremendously impressed by the majestic and wild personality of this bird, its vigor, its almost frantic aliveness. She flew off after five minutes and in another five returned, calling once and going in to roost at 7:30 on the dot. By the time we regained the road it was quite dark.

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Bits and Pieces Part 5: More on Range and Habitat Variety

I intended this long-delayed installment in the “Bits and Pieces” series to be the year’s final post. I also intended it to the be final installment in the series. While this may end up as the last post for 2017, I’ve decided to cut this short and save some discussion for what I anticipate will REALLY be the final installment.

Follow the links for Parts 1, 2, 3, and 4.

I’ll begin by reiterating that my focus here is not just on records from outside what’s commonly believed to be the historic range but also on records from habitats that depart from the stereotype that has emerged since the 1940s. Those who have studied the ivorybill’s natural history in depth understand that the species was not limited to Singer Tract-like habitats, and Tanner himself made this clear. Nevertheless, there’s a widespread tendency to think about habitat quality with a somewhat romanticized image of the Singer Tract – a vast contiguous area of old growth or virgin forest with huge trees and a high canopy – as the touchstone; Matt Courtman blamed this tendency on internalized beliefs. And for my part, I sometimes find it hard to shake these beliefs.

Ivorybill anatomy is specialized and particularly well-adapted to scaling bark, but the specialization pertains to securing food sources not easily retrieved by other woodpeckers (including Pileated) during the breeding season; it is not a specialization tied to particular tree species or habitat types.

Before moving on to a discussion of other records that don’t fit the Singer Tract model, I wanted to address something Cyberthrush said in an October post linking to this series. He wrote:

One of my hopes for the widespread USFWS/Cornell search was that it would at least narrow any possible IBWO persistence down to a very few (perhaps 2-3) localized areas; instead the failed endeavor left open the possibility of 2 dozen or more (sometimes little-birded) areas that scarce IBWOs might conceivably utilize. The lack of a single Ivory-billed Woodpecker appearing on remote, automatic cameras by now at more traditional and well-searched areas remains a pretty devastating obstacle to hope for the species… unless indeed it has found a home in the canopies of less-obvious, lightly human-trafficked woodlands.

I don’t want to hold out too much false(?) hope for this species, but on the other hand I believe most southeast woodland habitat is rarely birded in any regular or significant fashion and the vast majority of individual woodland birds are never systematically recorded — moreover, the ornithological literature is rife with weak, unscientific conclusions/generalizations/assumptions about bird behavior, and perhaps even bird biology. There’s just a lot we don’t know, while pretending we do.

While I don’t share Cyberthrush’s perspective on the lack of remote camera photos (or canopies), he makes very good points about the overall paucity of birding activity in many southeastern forests (I have never encountered other birders in the field) and about the limits of our knowledge.

With regard to his disappointment in the organized search effort, I suspect his hopes were founded in part on similar internalized beliefs; these beliefs were reflected to some extent in the excellent lists of potential habitat compiled by Bob Russell and Bill Pulliam that were so widely referenced a decade or so ago. That’s not to say the listed locations were unworthy of attention (and some of them have yet to receive much); however, there are many other areas that were not included.

In discussing his search efforts in one of these areas, Bill summed it up very well:

Many forest birds have modified their habitat usage in recent decades and centuries. Chimney Swifts are an obvious example; also quite telling is the Vaux’s Swift which has only begun moving out of old growth and into chimneys in the last few decades. But of more direct relevance, consider the following quotes:

When found they are usually in regions of original forest growth, rarely being seen where the woods have been once cut over. […] As this Woodpecker seems not to possess the faculty of adapting itself to the new conditions created by civilization, it is quite possible that it will not long survive the passing of our primeval forests. T. Gilbert Pearson, Birds of America, 1936.

Its presence in a region is more often revealed by the large cavities it excavates in dead stumps and trunks than by actual observation of the bird itself. […] This species is common only in the wilder parts of its range. Frank M. Chapman, Handbook of Birds of Eastern North America, 1939.

Both of these early 20th Century characterizations are of the habitat requirements of the Pileated Woodpecker. In fact, as we all know, over the intervening decades Pileateds managed to adapt to forest fragmentation and second growth quite well, thank you, and are now widespread in habitats well beyond the range of what was described in the 1930s.

There’s also another fundamental, perhaps somewhat tautological factor at work. If in fact Ivorybills were an obligate old-growth bird, then yes, they are now extinct. If they were never able to utilize second growth and fragmented forest, then there is absolutely no reason to be looking for them now anywhere. But even given the historical accounts of their habits they demonstrated a bit more flexibility than this; and given the actual history of Pileateds and various other forest birds since the industrial revolution, it seems brash and unjustified to presume that the habitat utilization of a 21st Century Ivorybill would be the same as that of one in the 19th Century.

We now know that even within the Singer Tract, ivorybills nested successfully at Mack’s Bayou, an area that was predominantly second growth, and I’d suggest that ivorybills showed more than “a bit more flexibility”, when one looks at the historical record.

As Fangsheath at ibwo.net has pointed out both on the forum and in an email, most of the ivorybill localities referenced by Tanner are from within 20 miles of the coast, and “[t]hese coastal forests are quite different from the Singer Tract.” In many of these coastal areas, tree size would have been smaller, the understory would have been thicker, and the canopy would have been lower due to hurricanes and other factors. In addition, the coastal records may have implications for survival in fragmented habitat types.

There are a number of records from Florida and South Carolina involving offshore islands. While most if not all of these offshore islands would have been covered in old growth forest at the time of collection, reaching them would have required crossing expanses of open water or marsh.

In South Carolina, there were multiple reports from barrier islands into the 1880s. A specimen collected in 1879 or 1880 is now lost. Hoxie, writing in 1918, reported that ivorybills were generally “unpersecuated or harmed by man” and that they had opportunistically fed on the barrier islands, following hurricanes, but disappeared when the food supply was exhausted.

My knowledge about Florida and conditions there is limited, but it seems clear that ivorybills lived and bred in a variety of habitats. Florida is also the largest single source of specimens and probably had the largest ivorybill population in the country. What may also be relevant is their apparent use of of mangrove forests, including potentially some 1-2 miles away from the mainland, especially in the Everglades region. As with barrier islands, use of this habitat may have involved crossing some open water between mainland forests (e.g., Big Cypress, associated forested sloughs, and open pine woods, leading to the Gulf of Mexico) and mangrove forests, both along the coastline and in the area referred to as the Ten Thousand Islands, extending south to where Tanner relayed reports during the 1930s from Shark and Lostman’s Rivers within what is now Everglades National Park.

To end this tour of ‘unexpected’ habitats and ‘extralimital’ records, let’s jump north and west by a thousand miles or so and consider records from Arkansas/Missouri and Virginia.

The Arkansas/Missouri records are from George Featherstonhaugh who explored the area in the 1830s and published his account in 1844 as Excursion Through the Slave States from Washington on the Potomac to the Frontier of Mexico; with Sketches of Popular Manners and Geological Notices. Featherstonhaugh reported seeing ivorybills in two different locations – one from a bottomland area above the confluence of the Ouachita and Caddo Rivers, in the vicinity of present day Arkadelphia, AR. This passage is from Volume 2.

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The second location appears in Volume 1 and is more interesting for the purposes of this discussion, since it involves fire damaged upland forest, likely oak-dominated, with hickory and perhaps some shortleaf pine. It’s not clear whether the site is in present day Arkansas or present day Missouri. Either way, it appears to be on the edge of the Ozark Plateau where it meets the Mississippi Alluvial Plain. As an aside, Featherstonhaugh seems to have had an eye for detail and a dry sense of humor:

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Whether the birds were resident in this area or were merely feeding opportunistically in the fire damaged table-land, the habitat involved bears no resemblance to the Spanish Moss festooned, swamp forest stereotype.

Back in October, Matt Courtman discovered that Thomas Jefferson included the ivorybill on his list of Virginia birds found in Notes on the State of Virginia (1785). While some authors have suggested that Jefferson was merely following Catesby, it has also been argued that Jefferson’s list was “a product of his personal observations”. If this is true, Jefferson’s observation would not have been from the Great Dismal Swamp (where Pearson thought ivorybills might be present in the early 20th-century), since Jefferson never went south of Norfolk.

Thomas Nuttall, writing in the 1830s, described the ivorybill as being “seldom seen to the north of Virginia and rarely in that state.” In The History of Ornithology in Virginia (2003), Johnston dismisses Nuttall’s assertion but also points to a much earlier and unambiguous record from an upland site, one that seems to have been otherwise overlooked.

The record is from a Native American midden dating to the early Woodland period, ca. 300 CE (AD). The site, Daugherty’s Cave, was used for millennia. It’s in the western part of the state, far from the coastal plain, at an elevation of approximately 2000′. The context suggests that the remains were not trade goods, and Johnston deems it to be “the only known record of this bird from Virginia”.

I’m struck by the fact that if the ivorybill had gone extinct before 1700, and we only had the scant archaeological record to go on, we’d imagine it to be a bird associated with upland forests. On a more serious note and perhaps one more relevant to the discussion that will follow in the next post, I wonder whether the appearance of ivorybill remains in Appalachian middens around 1800 years ago is related to the spread of maize agriculture and tree kills associated with this new farming technology.

So what inferences can be drawn from all this information and what are the implications? I have some thoughts, not all of them had occurred to me before I began  this exploration, and I hope they’ll inspire readers to reflect and come up with their own new insights.

The first and perhaps most mundane observation is that the range maps with which we’re all so familiar, like the one below from the IUCN, reflect the ivorybill’s status after what was likely a long period of decline, especially east of the Mississippi. Unfortunately, these maps reinforce ideas about habitat requirements and tree species associations that are, at best, oversimplifications.

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For contrast, I’ve updated the map I created showing most of the records discussed in this series.

This is not to suggest that reports from outside this “historic” range should be taken seriously today. The map is a fairly accurate reflection of the reality post-Civil War. The more important questions are why the range started to shrink, probably during the 18th-century, and what this more complex analysis of potential habitat types might imply for the species’ survival. That will be the subject of the next and final installment.


Trip Report: October 17-23, 2017

The first trip of the season was relatively uneventful, although we heard possible single and double knocks on Thursday morning and afternoon. Unusually heavy hunting activity and bad weather kept us out of the field on Saturday the 22nd and most of the Sunday the 23rd. Peggy Rardin Shrum joined me from Tuesday through Friday.  Tommy Michot was with us Tuesday, Wednesday, and Thursday, and Steve Pagans joined us Wednesday through Friday.

Tommy has been very good at encouraging us all to do more stopping and listening. My focus on looking for feeding sign has probably led me to do more walking than I should.  We’ve also started experimenting with playback of a couple of the March calls, cleaned up, amplified and looped by Phil Vanbergen and would like to offer it other searchers for their use. Feel free to email me for an MP3 if you’re unable to pull it from the site.

The amplification and cleaning up highlights the differences between many of our sounds and those recorded in the Singer Tract (though I still think the species involved is the same). Agitation and disturbance may account for the shorter, sharper sound of the John’s Bayou calls, and as has been discussed in prior posts, written descriptions of the calls, including Tanner’s, point to a good deal of variation.

We observed that playback of these calls often provoked responses from woodpeckers of all kinds at close to the same level as Barred Owl playbacks, though this was impressionistic not quantified. Crows and raptors sometimes seemed to react as well. I played around with some other sounds chosen more or less at random – Goldfinch, Blue Jay, Ring-billed Gull, Black-backed Woodpecker. None of these seemed to have much effect, though the Black-backed did appear to evoke a smaller number of woodpecker reactions.

Water levels were low enough to enable us to get into some of the less accessible areas, but the need to  deal with our trail cams prevented us from spending a lot of time exploring. There were no indications of woodpecker activity on the target trees, and we continue to have problems with camera malfunctions. Two of the four we had deployed seem to have failed since June; one of these may have been damaged by a tree fall, but both cams have the same issue – shutting down after booting up. We’re trying to identify the glitch and determine whether the cameras are reparable.

Tuesday, October 17

We visited the northern sector to check on our two northernmost camera deployments. The first of these (now discontinued) was a standing hickory with signs of insect damage. Tommy and Phil Vanbergen had changed out the batteries in August, and 64% of the charge remained. The second target is a hickory about 200 yards away that had lost its top in a spring storm and an adjoining beech that had also been damaged. Since August, a large hickory had fallen, bringing down a number of limbs from other trees in the process and perhaps damaging the camera without hitting directly. In addition, a large fallen oak limb obscured most of the trunk of the main target. We pulled the camera when we discovered the apparent malfunction. On the return hike, we headed east to a part of the area I had not previously explored and that has had little coverage.

Wednesday, October 18

On the morning of the 18th, I stopped for breakfast at the place closest to our search area.  Early on weekday mornings, it’s a hangout for law enforcement officers and older folks, as well as various people passing through on their way to work. A sheriff’s deputy and a couple of older men had been in the place on Tuesday, discussing local history. All three were familiar faces, as no doubt, I was to them.

For the first time, this particular bunch engaged me in conversation, asking whether I was hunting. I said no, I was looking for birds and taking pictures. They asked what ‘what kind of birds’, and I said woodpeckers. “What kind of woodpeckers?” “Rare ones”, I replied. They initially thought I was referring to “itty bitty ones”, Red-cockadeds, but I explained that I meant big woodpeckers. “You mean those Indian Hens” (meaning Pileated), one asked. I told them what I was looking for was similar but not the same and took the opportunity to show them pictures from my iBird Pro app.

The Deputy Sheriff and one of the men recognized the Pileated but said they’d never seen an ivorybill. The third guy pointed to the ivorybill image, and said, “I used to see them when I was hunting over on . . . but I gave up hunting seven years ago.” This is the second or third local claim I’ve heard from this area, which is several miles away from the focus of our efforts across a major highway.  It looks decent on Google Earth. While I’ve been wary of engaging in too much conversation with locals, it sometimes provides interesting intel, and this evolved organically; I didn’t reveal our location; and I hope it won’t result in too much gossip.

I met up with Tommy and Peggy, and we went to the southern sector to check on the other camera deployment (another tall hickory stub) to discover that one of the two cameras had failed in the same manner as the one at the northern location. We changed the batteries on the functioning camera and pulled the malfunctioning one. We met up with Steve, who had arrived later and followed another route, in the early afternoon and hiked out with him.

Thursday, October 19th

Peggy, Tommy, and I devoted the morning in the northern sector, exploring the less-visited eastern side. At approximately 8:35 we did a series of double knocks, which did not produce any immediate responses. We remained in place, and shortly before 9, we heard several single and double knocks from south of our location.  We were not recording at the time, and I considered them to be moderate possibles. We met up with Steve, who had been some distance north of us, about an hour later; he had heard our ADKs but not the apparent responses.

In late morning, we headed west and moved the functioning trail cam to the nearby hickory/beech blowdown. This is where Peggy, Tommy, Phil, and I had heard some knocks in June. It took a group effort, but we were able to move the large oak limb that was obstructing the view of the hickory bole. We redeployed the camera, trained on the bole. Given the season, it seems unlikely that this stub will be scaled in the next several months, but I anticipate leaving these camera traps in place for an extended period.

We stayed in this spot for lunch and did a little more exploring in the immediate vicinity before heading back toward the trailhead in the early afternoon.  At approximately 2 pm, as we were approaching the spot where the March recordings were made, we heard several ambient knocks, also moderate possibles, but were unable to generate any responses.

There was more shooting than usual in the area during this trip and there were distant industrial noises from time to time. These were all easy to distinguish from the possible SKs and DKs.

Friday, October 20th

Peggy, Steve, and I returned to the same vicinity and spent our time in the less visited eastern half, some of which was familiar to Steve. In addition to be being hard to reach, the terrain in this area is difficult, making it more difficult to explore.

We did not see or hear anything of note, although I found some suggestive older scaling on boles – one example on a sweet gum and one on the dead side of a still live hickory. I’d estimate that this work is at least a year old. The hickory work is of the kind I think may be diagnostic for ivorybill, and the sweet gum work is interesting for being on the bole and also for apparent large exit tunnels. I also find the excavation on the hickory to be of potential interest. The wood does not appear to be soft, and the digging does not look like typical Pileated Woodpecker work. In a couple of instances, Tanner mentioned how Ivory-billed Woodpecker work resembles that of the Red-bellied Woodpecker except for appearing to have been done by a larger animal. This hickory excavation may fall into that category.

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Old scaling on sweet gum bole

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Scaled hickory bole with unusual excavation

Saturday, October 21

I met Peggy at the breakfast place, which was unusually busy and filled with hunters. It became clear that I had not picked the best time to be in Louisiana, as this was a big hunting weekend. In addition, the weather forecast called for heavy rain by late morning. Peggy had a long drive ahead, and we agreed that there would be little point in going into the field. She left for home, and I opted to drive around, specifically to see if I could find any easy access point for searching in the vicinity that local people had mentioned and also to scout other nearby areas for potential. I had very limited success, getting a look at part of the bottom, which looked like it might have potential at a cursory glance.

The rains came on Saturday night and continued through Sunday morning.

Sunday, October 22

The rains kept me out of the field until noon, at which time I went to the eastern sector and and spent about three wet and unpleasant hours there. It rained sporadically, avian activity was generally low, and visibility was poor due to cloud cover. I didn’t see or hear anything of interest.

On Monday, I awoke to an email with a very detailed account of a sighting by someone I’ve known for several years. I may devote my next trip to following up on this report and to looking at areas in another part of the state. In any event, the next post will likely be the final in the series that this one has interrupted.

 


Bits ‘n’ Pieces Part 1 – Louisiana Conservationist, Matt’s Take on the March Calls, and More

I had planned on writing just one more post before my next trip to the search area, but based on a small but important new development, I’ve decided to divide it into two parts. Part 2 will follow within a week or so. It will focus on the historic range both pre- and post-contact, beavers, and some further thoughts on how the ivorybill might have survived.

First, a small news item from the search area: last month Tommy Michot and Phil Vanbergen visited to check on the trail cams. One of the deployments (two cams) was inaccessible due to high water; unless flooding was extraordinary, the cameras themselves should be okay. Phil and Tom were able to reach the other two locations without difficulty. The target trees were untouched, and there was sufficient battery and card-life to keep the cameras operational until my next trip. They did not see or hear anything suggestive of ivorybill during their visit. I appreciate their braving the August heat and taking the time to get to the area.

I’ve been reviewing copies of Louisiana Conservationist (formerly Louisiana Conservation Review), the official publication of the Louisiana Department of Wildlife and Fisheries (formerly the Department of Conservation). Copies of the magazine, which is in the public domain, can be found in the Louisiana Digital Library. In the course of my research, I found one real gem and a couple of interesting pieces of less significance.

The gem is the initial report on the 1932 Singer Tract rediscovery and T. Gilbert Pearson’s visit to the area. Pearson was the first professional ornithologist to observe the Singer Tract birds. I’ve written previously about Pearson’s visit and have referenced newspaper accounts of his observations. At the time, I was focused on feeding sign and the statement about feeding on rotting stumps. As a result, I overlooked the important fact that Pearson had been searching for ivorybills to no avail since 1891; this highlights the difficulty in finding ivorybills, even during the era of relentless collecting.

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The Ivory-Billed Woodpecker: Rare Bird Considered Extinct – Found in Louisiana, Margaret A. Coogan, July 1932, Louisiana Conservation Review

The newspaper articles were somewhat less detailed than Coogan’s account, which includes some interesting tidbits. It seems likely that Pearson himself provided the information to Coogan, either directly or via Armand Daspit. There’s an inaccuracy; the mention of carpenter ants as prey is not supported by the literature.* The only record of nesting in pines is in Thompson (1885), a record that Tanner deemed “questionable”.

Edited to add: Hasbrouck (1891) included a second-hand claim of a nest in pine from northwest Alabama. Tanner accepted the report but possibly not the claim of a nest, as the latter is not mentioned in the monograph.

Somewhat more interesting is the observation, “Occasionally it feeds on the ground like a Flicker”.  In 1937, Allen and Kellogg would publish a paper describing their 1924 observation of a female ivorybill foraging on the ground and “hopping like a Flicker”. It’s possible that Pearson was aware of this observation, and the reference to scaling the bark of dead pines suggests this is so. (There were no pines in the Singer Tract.) At the same time it’s also possible that Pearson observed the Singer Tract birds foraging on the ground or described foraging behavior based on general knowledge of how ivorybills in Florida, where he grew up, typically fed.

More significant and relevant to the recordings Matt Courtman and Phil made in March of this year is the description of ivorybill calls and the pattern of calling observed. I didn’t pay much attention to the description, but Matt, who was present during the extended period of calling on March 15 was struck by it. For Matt, the correction of Audubon was significant, and as he posted on Facebook: “Please note the description of the calls being from “one to fifty” over a few minutes. This matches perfectly what we recorded in March. Very exciting!!!” Matt’s strongest doubts about the calls had to do with cadence and the lack of calls in groups of three.

Matt elaborated in an email this morning. I asked him to allow me to post it in full, and he graciously agreed. His perspective sheds additional light on the March recordings, among other ivorybill related matters. It’s worth reading.

The following explanation might be excessive, but an appreciation of my history with the ivorybill is necessary to understand the visceral response that I had to reading the 1932 article reproduced by Mark.
 
My love of nature generally, and of birds in particular, was cemented by a visit to the LSU Museum of Natural History when I was eight. In reading George Lowery’s Louisiana Birds, I was beguiled by his account of having seen ivorybills in the Singer Tract (Madison Parish, near Tallulah) on Christmas morning, 1933. In a letter that I wrote to Dr. Lowery (adorned with my drawing of a pair of IBWO), I asked him if he thought that any ivorybills still existed. He promptly replied that he sure hoped that they did. I can’t be certain about all of the contents of a letter from almost 50 years ago, but I THINK that he expressed a belief that, due to the relative inaccessibility of the ivorybill’s putative environment, that isolated pockets of ivorybills could have survived undetected for decades.
 
In his reply, Dr. Lowery offered to show me the ivorybills in the LSU collection. The very next week, my father and I went to Baton Rouge for the LSU-Mississippi State football game. In an act typical of his unfailing grace and generosity, Dr. Lowery waded through post-game traffic to open up the Museum at 10:30 p.m. just for us. Holding ACTUAL ivorybills in my hands, set me on the vacillating belief/disbelief course that I still follow five decades later. Based on recent developments, my current course is trending overwhelmingly toward the shores of belief.
 
Dr. Lowery’s national preeminence as an ornithologist was impressive: under his direction, LSU was responsible for the discovery of more new bird species than any other institution during Lowery’s tenure; during this period, an entirely new GENUS of owl was discovered by LSU in Peru and named in Dr. Lowery’s honor. Despite that, his relative optimism about the ivorybill was not shared by ANY serious Louisiana birders that I knew. In fact, other ornithology professors around the state would scoff at Lowery’s optimism behind his back. This all came to a head when, in 1971, Dr. Lowery announced that he believed that photographs (subsequently revealed to have come from Mr. Fielding Lewis) sent to him depicted a LIVING ivorybill. Whispered skepticism gave way to thinly-veiled ridicule: everyone whom I knew to have an opinion on the matter voiced their belief that Dr, Lowery was a gullible victim of an obvious hoax. 
 
At the October, 1971 meeting of the Louisiana Ornithological Society, two (inebriated…birding WAS a different culture back then:)) men tried to coax me into asking Dr. Lowery exactly where the photographs had been taken.  They figured that since Dr. Lowery and I were close, and, since I was only 10 years-old, that he might tell me. Though young, I wasn’t stupid. I declined.
 
In sum, although I wanted to believe Dr. Lowery, the birders with whom I was in constant contact with had nothing but contempt for anyone who “believed in” ivorybills. Aside from Dr. Lowery, everyone seemed to accept the Gospel According to James Tanner: after 1944, no remaining virgin bottom-land hardwood forests meant NO remaining Ivory-billed Woodpeckers. 
 
To demonstrate the sway of the Tanner Gospel, even during flickers of hope regarding IBWO, circumstances were viewed through Tanner’s lens. For instance, in 1999, as (past) President of the Louisiana Ornithological Society, I was invited to participate in a state-sponsored search of the Pearl River Wildlife Area (near Slidell) to follow-up on David Kullivan’s reported sighting of a pair of ivorybills. Having some familiarity with the specifics of Kullivan’s report, I was surprised when I saw a map of the grids that we were assigned to search. The following colloquy ensued:
           
              Matt: [pointing to a specific spot on a map] I thought that Kullivan reported the ivorybills to have been near this campground.
              State Fish & Wildlife guy: That’s right.
              Matt: Well, why are we not searching any place NEAR that campground?
              State Fish & Wildlife guy: Because Tanner’s research showed that ivorybills were found only in really big trees, and there aren’t any really big trees there.
              Matt: So you believe that Kullivan was correct in saying that he saw ivorybills, but you think that he was incorrect about WHERE he saw them?
              State Fish & Wildlife guy: [insouciant shrug]
 
Moral of the story: with the vast majority of people, historical, remote Tanner Gospel trumps actual, recent, credible observation.
 
So, for most of my life prior to 2017 I had been surrounded exclusively by Tanner-quoting ivorybill “deniers.” Despite my veneration for Dr. Lowery (who had passed away in 1978), I could not but help to have their rigid doubts shape my views regarding the existence of IBWO.  In February, 2017 my friend, Frank Wiley passed away. Along with Mark Michaels, Frank had founded “Project Coyote,” in hopes of finding and documenting ivorybills. As a tribute to Frank, I decided to visit the Project Coyote search site in Louisiana. I had zero expectations regarding the trip. In fact my dominant thought prior to the trip was: “I am going to make a concentrated effort, spend several days in the woods, observe nothing to suggest the continued existence of ivorybills, and, then, FINALLY extinguish any lingering delusions about ivorybills so that I can get on with more productive, practical uses of my time.”
 
In preparation for the trip, I began to read through all of the blog entries on Project Coyote’s website.  There, through the heroically-diligent work of Mark Michaels, I discovered something shocking: that Tanner’s own data did not support the chief tenet of the Tanner Gospel, that ivorybills were found only in virgin bottom-land trees. As with the Bible, many people quote Tanner to support a particular assertion, but few people have actually read all of Tanner’s work.
 
Back to the issue at hand (finally!): why was the 1932 statement regarding the ivorybill call so meaningful to me?  The passage in question was: “The bird’s note is a peculiar nasal ‘yank,’ NOT REPEATED THREE TIMES as Audubon states, but as many as from ONE TO FIFTY in a few minutes (emphasis supplied).” For me this was like finding the missing link. The only thing that had conjured doubts (about the sounds being from ivorybills) in me about my recording was that the notes did not come in series of threes, but rather were relatively monotonous and evenly-spaced over an extended period of time. Prior to reading this 1932 description, I had never even considered that Ivory-billed Woodpeckers would call in any way that was NOT a series of three notes.
 
My myopia had been further compounded by my frequent exposure to the only widely-accepted recording of the ivorybill. The 1935 Cornell recording definitely presents as a series of three notes. As anyone can attest who has used the Cornell recording as playback when looking for ivorybills, hearing it repeatedly primes your brain to expect a series of three notes to be the only “valid” response that would indicate the presence of an ivorybill. Mark has since informed me that the literature contains many references to “non-three” note descriptions. In fact, I probably have encountered many of those same descriptions over the years. As with Tanner-induced single-mindedness, however, I had never INTERNALIZED anything other than, “If I ever hear an Ivory-billed Woodpecker call, it will come in the form of three notes.”
 
As I was reading the 1932 passage, my wife, Lauren, could tell that I was reacting emotionally to what I was reading. For the ONLY time in our eight years of wedded bliss (actually, not hyperbole) regarding something that I was reading, she asked: “Are you OKAY?” I find my visible, somatic response to be at least as important as all the intellectual reasons that I could adduce to explain the importance of the 1932 description. 
 
In sum, that 1932 description removed whatever lingering doubt that I had maintained regarding the probable source of the sounds that I recorded on March 15, 2017. Subjectively, I am convinced that I recorded at least two (and probably three) Ivory-billed Woodpeckers that day. Objectively, I can state unequivocally that the calls were consistent with those to be expected from ivorybills. While acoustics alone will never be sufficient to establish the continued existence of the ivorybill, for me the only pertinent question that remains regarding the 3/15/17 recording is: “Could anything other than an ivorybill also account for those sounds”?
 
Congratulations on reading my tome in its entirety! Please feel free to share with anyone. Of course, I would be happy to answer any questions raised herein.

The other interesting tidbits from Louisiana Conservationist pertain to possible ivorybill sightings in the 1950s. Both items (letters from readers and responses from state officials) are certainly questionable, but they also point to the way Pileated Woodpecker became the default, even when the description was inconsistent with PIWO.

The first is interesting for its location. Urania, Louisiana is southwest of the Singer Tract and is relatively close to the Project Coyote search areas. It was founded by Harry Hardtner in the 1890s and is considered the birthplace of conservation and reforestation in Louisiana. The image that prompted the letter is included for reference.

Screen Shot 2017-09-15 at 3.44.14 PMScreen Shot 2017-09-15 at 3.28.27 PM

The second letter is peculiar, but the description is considerably more suggestive of ivorybill than Pileated – like a Red-headed Woodpecker but the size of a chicken.

Screen Shot 2017-09-16 at 8.45.06 AM

There’s one additional tidbit that doesn’t pertain to Louisiana. In the past, I’ve wondered about record committee submissions and how many there may have been over the years. A divided Arkansas committee accepted the Big Woods report (a fact that’s often glossed over in the literature), while the Florida committee rejected the Auburn reports. Other than these submissions, I was aware of one from Texas, from out of range and in unlikely habitat. I recently ran across another, from Florida, also rejected but interesting nonetheless. Here it is, for what it’s worth:

Ivory-billed woodpecker, Campephilus principalis.
FOSRC 2011-852. This bird was described from an observation in suburban St. Augustine, St. Johns Co., on 13 April 2011. Although the observation included key characters of the Ivory-billed Woodpecker, such as a white bill and white pattern on the back while perched, the observation was at a distance of 30 m and made without binoculars. It is the Committee’s opinion that the only acceptable submissions of this species would be those with veri able evidence (e.g, identifiable photographs or video). The recent controversy over video recordings, audio recordings, and sightings in Arkansas (Sibley et al. 2006) and Florida (FOSRC #06-610, Kratter 2008) calls into question whether the species may have persisted into the twenty-first century.

More soon.

*Ants are described as a prey species in Bendire (1895), but this is based on a misreading of Thompson (1885). Allen and Kellogg (1937) mention an observation involving suspected feeding on ants but found no ants or termites when they examined the substrate. The closest thing to evidence for ants as prey involves a Cuban Ivory-billed Woodpecker with a hugely overgrown bill that was observed feeding on arboreal termites – a species not native to the continental United States. It was observed and collected by Gundlach in 1843 and was also being fed grubs by its companions. Jackson speculates that this might have been a young adult bird, but given the extent of the hypertrophy, this strikes me as being somewhat unlikely. I’ll opt for the altruistic possibility that Jackson also posits. (Jackson 2004).

 


Repost with Addendum: Ivory-billed Woodpecker Sightings and Evidence 1944-2003: The Partially Hidden History

I’m reposting an entry from February 2015 with some new commentary as prologue.

I recently received a Google alert about a new paper on statistical approaches to extinction relying on sight records. According to the paper, which has not yet been peer reviewed:

We have shown that the rate of sightings is the strongest indicator to infer extinction, and too much information about the quality of the sighting can actually be detrimental. Ideally a sighting record would be a list of certain and uncertain sightings only.

I’m curious as to how this model might treat the ivorybill, using the sighting data compiled and analyzed by William C. Hunter in the U.S. Fish and Wildlife Service’s Recovery Plan, a document with which many extinction modelers seem to be unfamiliar.

I’m not trained in statistics, and the literature on this subject is often over my head, but I’m familiar with the concept: “garbage in, garbage out”. Unfortunately, when it comes to the ivorybill, information that is repeated in the statistical papers is often inaccurate:

“For example in 2005, based on a brief sighting and a pixelated image, the ivory-billed woodpecker was declared to have been rediscovered (Fitzpatrick et al., 2005), resulting in the mobilisation of resources for management strategies and recovery plans (Gotelli et al., 2012). However, based on the evidence its rediscovery was brought into question (Sibley et al., 2006), and subsequent extensive searches have failed to result in further sightings (Gotelli et al., 2012).” Roberts DL, Jarić I. (2016) Inferring extinction in North American and Hawaiian birds in the presence of sighting uncertainty. PeerJ 4:e2426c 

An example of a species with a high false detectability is the ivory-billed woodpecker. After 2006, when the US Fish and Wildlife Service offered $10,000 for information leading to an ivory-billed woodpecker’s nest, it was ‘observed’ 14 times and audio recorded 300 times. Nonetheless, the reward remained uncollected (Newton 2009). Lee, T. E. (2014), A simple numerical tool to infer whether a species is extinct. Methods Ecol Evol, 5: 791–796.

Neither of these papers applied the models described to the ivorybill, and I’m not commenting on the validity of the models themselves. I’m pointing to how peer-reviewed literature can sometimes function as an echo chamber in which inaccurate information gets repeated as fact.

While it’s true that extensive searches have failed to obtain indisputable proof, the Luneau video, however controversial, cannot be characterized as a “pixelated image”. There were many more sightings in Arkansas and elsewhere, and in Arkansas, numerous kent-like calls and double knocks were heard and recorded over several seasons.

The book by Newton cited in Lee is Hidden Animals: A Field Guide to Batsquatch, Chupacabra, and Other Elusive Creatures, clearly not a serious scientific treatment of the ivorybill and apparently not a very well-researched one. There were in fact 15 Arkansas sightings between 2004 and 2005 and 14 in 2005-2006. The reward, which was for $50,000, applied to Arkansas only and was offered by the Nature Conservancy, not the USFWS, in June 2006. The source of the claim that audio was “recorded 300 times” is not clear, nor is the meaning. Inaccuracies aside, it’s an enormous logical leap to base an assertion about high false detectability on the inability of an unknown number of bounty hunters to locate a nest in ~500,000 acres of forest.

It may well be true that the ivorybill is more prone to false detectability than some other species; its iconic status makes this seem likely. It’s also true that there have been a number of organized searches for the ivorybill and that the number of sightings has increased as a result of publicity and search activity, at least during the first decade of this century. Nevertheless, many of the records between 1944 and 2003 listed in the USFWS Recovery Plan were unrelated to publicity or organized searches and were incidental to other activities, including bird surveys. In addition, the Recovery Plan tally included some qualitative analysis of the sightings, and an unspecified number of reports were excluded as probable false detections.

I find it odd that Appendix E of the Ivory-billed Woodpecker Recovery Plan is seldom if ever referenced in the recent literature, including Birdlife International’s species account (which I’m honored to say does reference the post below). It’s an official government report and is the most extensively researched document of its kind. I suspect that many readers will be unfamiliar with it and think it merits quoting at length; I’ve bolded some important passages.  I encourage people to click on the link above and read the rest.

Here, a potential encounter is defined as a report not easily explained as something other than an Ivory-billed Woodpecker on the basis of description of the bird, the type of habitat in which it was encountered, and distribution. After the Arkansas announcement was made, post-1944 reports were compiled prior to the 2005 announcement of an Ivory-billed Woodpecker being sighted in Arkansas. A map was produced of these potential encounters in Service brochures. These potential encounters were based on those discussed by Jackson (2004) or otherwise in Service files as “probably reliable,” defined here as not obviously another species. A review of other published literature and files maintained by some State working groups included other potential encounters that are cited and used in this treatment (both before and after 1950). Excluded from further consideration were reports that likely described other species (especially Pileated, but also Red-headed and sometimes other woodpecker species), as well as those reports outside the historical range of the species (as depicted in Tanner 1942) and in unlikely habitats such as golf courses and backyards. The reports between 1945 and 2005 considered further vary in detail, with some accepted based solely on the credibility and reputation of the observer. Reports since April 2005 (i.e., the Arkansas announcement) are similarly treated, but at least one diagnostic field mark had to be observed (most often the white trailing edges on a flying or perched large woodpecker).

It is important to understand the type and level of documentation accepted for this species’ persistence at the time when most collecting of specimens began to trail off (i.e., after 1900) compared with those reports which were accepted without question previously. While most previous treatments break down reports by State, here it is believed that important insights can be made by comparing reports, type and level of documentation, by decade starting with the 1800 and ending with the present. References for those reports besides those of Tanner himself prior to 1940 are provided in Tanner (1942, with cross-reference to location on his maps, his figures 3-10) and are so noted here.

Results and Discussion

The number of locations with Ivory-billed Woodpecker reports peaked between 1880 and 1910, the same period when most specimens were collected (Figures 1, 2). The number of locations with potential reports after 1940 generally dropped below the number of locations with all reports between 1900 and 1940. However, when including only potential encounters between 1900 and 1939, the range in number of locations among decades was roughly similar to the number of locations with potential encounters in the decades between 1940 and 2009, only dropping below 10 locations during the 1990s. The number of locations within each decade with multiple reports among years never exceeded 10 per decade prior to the extensive efforts underway after 2005 to search for this species.

Prior to 1940, only a small percentage of locations from decade to decade provided the source of reports from multiple years within any one decade, ranging from 12 to 28 percent of all locations with birds reported within each decade (Figures 3, 4). After 1940, there was a slight increase in the percentage of locations with multi-year reports in the later decades, ranging from 9 to 51 percent of all locations with birds reported within each decade. Despite this increase in locations with reports from multiple years there was no definitive documentation of persistence at any of these locations. Similarly, a very low percentage of locations with reports spanning more than one decade is documented in the historical record, but again with a slight increase during the latter decades (Figures 5, 6). Reports continue to come from most of Tanner’s regions into the present day with an obvious shift from those regions that included Florida to regions elsewhere (Figure 7).

In summary, there is no evidence that the Ivory-billed Woodpecker was ever widely or consistently relocated in the same areas from year to year or from decade to decade prior to 1940, despite the impression one may have about birds at the Singer Tract during the 1930s. Actually, during Tanner’s study the chore in locating birds often took days or weeks even where pairs or family groups were known to occur from previous years (and actually only one nesting pair at John’s Bayou was consistently relocated during his entire study). Whether the birds were truly more nomadic than previously thought, or whether the low percentage of repeated locations historically has been due to the search patterns of ornithologists and collectors is unclear. What is clear is that the present pattern of reports that do not effectively document occurrence of the species has been repeated from decade to decade for more than a century and that the number of locations with potential encounters within the same decade has varied little since the 1870s.

Whether or not many or all post-1944 reports pertain to actual Ivory-billed Woodpeckers will continue to be debated in some circles, and it also is possible that some of the reports dismissed for purposes of this treatment perhaps should not have been discounted so lightly. However, the pattern of credible-sounding reports accepted for this treatment from locations without firm documentation was from decade to decade slightly lower between 1940 and 2009 than the pattern recorded between 1890 and 1939. Most interestingly, the exceptional increase in locations with potential encounters during the present decade is on the surface similar to what was recorded during the 1930s, given both of these decades experienced a notable increase in amount of effort to firmly document the persistence of this species (with similar results despite substantially fewer observers involved in the 1930s than in the present decade).

 

RecoveryPlanE1&2RecoveryPlan3-4RecoveryE5-6RecovE7

One caveat about this material: the specific information in Appendix E is potentially subject to change in the future, but the overall patterns are likely to stay similar or the same.

Here’s the February 2015 entry.

This post is inspired in large part by an exchange of emails with Chris Sharpe, an ornithologist who is working on an IBWO literature review. Our correspondence revolved around the IUCN’s species account, which describes the ivorybill as “possibly extinct” and cites recent statistical analyses that suggest extinction is likely, as well as one that indicates survival is possible and another that concludes “very large search efforts are needed to detect small populations.”

Chris pointed out that there are many other species on the Red List that fall into a similar category with many unverified reports but in more remote habitats and nowhere near the search effort that has been expended on the ivorybill. While there’s some validity to this assertion, I think the reality is considerably more complex and that the ivorybill is in fact sui generis.

Many of the specifics of ivorybill history are little-known, and the statistical studies seem badly flawed. One focuses on collection rates but may not adequately address changing attitudes toward conservation in the early 20th century among other factors. Another is perhaps even more problematic for a number of reasons – most importantly its focus on “verified sightings”, which is a particularly complicated issue when it comes to the ivorybill. It omits numerous controversial sightings and does not include post-Singer Tract instances in which physical evidence was obtained, although the authenticity of that evidence has been contested. “Sidewinder” posted the abstract and a good summary of the findings on ibwo.net a few years ago:

Roberts, D. L., C. S. Elphick, and J. M. Reed. 2010. Identifying anomalous reports of putatively extinct species and why it matters. Conservation Biology 24:189–196.

As species become very rare and approach extinction, purported sightings can stir controversy, especially when scarce management resources are at stake. We used quantitative methods to identify reports that do not fit prior sighting patterns. We also examined the effects of including records that meet different evidentiary standards on quantitative extinction assessments for four charismatic bird species that might be extinct: Eskimo Curlew (Numenius borealis), Ivory-billed Woodpecker (Campephilus principalis), Nukupu`u (Hemignathus lucidus), and O`ahu `Alauahio (Paroreomyza maculata). For all four species the probability of there being a valid sighting today, given the past pattern of verified sightings, was estimated to be very low. The estimates of extinction dates and the chance of new sightings, however, differed considerably depending on the criteria used for data inclusion. When a historical sighting record lacked long periods without sightings, the likelihood of new sightings declined quickly with time since the last confirmed sighting. For species with this type of historical record, therefore, new reports should meet an especially high burden of proof to be acceptable. Such quantitative models could be incorporated into the International Union for Conservation of Nature’s Red List criteria to set evidentiary standards required for unconfirmed sightings of “possibly extinct” species and to standardize extinction assessments across species.

Here are the Ivory-billed Woodpecker sighting data they used:

Physical evidence: 1897, 1898, 1899, 1900, 1901, 1902, 1904, 1905, 1906, 1907, 1908, 1909, 1910, 1913, 1914, 1917, 1924, 1925, 1932, 1935, 1938, 1939

Independent expert opinion added: 1911, 1916, 1920, 1921, 1923, 1926, 1929, 1930, 1931, 1933, 1934, 1936, 1937, 1941, 1942, 1943, 1944

Controversial sightings: 1946, 1948, 1949, 1950, 1951, 1952, 1955, 1958, 1959, 1962, 1966, 1967, 1968, 1969, 1971, 1972, 1973, 1974, 1976, 1981, 1982, 1985, 1986, 1987, 1988, 1999, 2004, 2005, 2006

Data were from Tanner (1942), Hahn (1963), Jackson (2002, 2004), Fitzpatrick et al. (2005), Hill (2006), and Floyd (2007).

Some conclusions: For the Ivory-billed Woodpecker, the prior sighting record suggests that even by the time of the first controversial sighting, the species was relatively unlikely to remain extant (ca. 21% chance), regardless of the level of evidence (physical or independent expert opinion) used…the effect on the predicted extinction date will depend on the details of the sighting record. Including controversial sightings will, by definition, move expected extinction dates forward in time. An ever-increasing burden of proof should be required with increasing time since the last verified sighting. The burden of proof also should be greater when there is a pattern of frequent sightings prior to the last accepted record and lower when long periods between sightings are common in the historical record.

A second paper published in 2012 reached the same conclusion using 39 sightings “classified as certain and 29 classified as uncertain”.

The insistence on verification is problematic because it’s founded on an appeal to authority, and for much of the time frame in question, the primary if not sole authority was James T. Tanner. Tanner had a strong predisposition to dismiss every post-Singer tract report he received and was somewhat cavalier about reports he investigated in the late ’30s as well. (In fairness, Tanner did accept a number of post-Singer Tract sightings in an unpublished, late 1980s update to the records section of monograph.)

Tanner likely underestimated the population IBWO population in the late 1930s. At minimum, he missed six pairs in Mississippi, according to Jackson ( In Search of the Ivory-billed Woodpecker, pp. 60-62.  These details reinforce the point made by “Fangsheath” of ibwo.net that, for the ivorybill at least, demanding verification leads to “a rather vicious circularity”. In a recent email, Fangsheath also pointed out that “the Roberts et al. scheme fits tidily into the narrative created by Tanner, that the Singer Tract was the last hope of the ivory-bill, and that when that: wilderness was lost the bird essentially became extinct . . . Tanner searched across several states for the bird and found none elsewhere, yet he himself believed that the bird survived in a number of areas. And so we have a curious contradiction – on the one hand an appeal to authority is being used to exclude many sightings, and on the other hand that same authority is saying the bird exists in areas where sightings are excluded. The mythos that the bird had very specific habitat requirements clouded every search effort and every sighting evaluation, before and after 1944.”

Fangsheath’s observation about the impact of Tanner’s narrative on future search efforts is profoundly important. Tanner’s ideas about habitat, which were in large part a product of his cultural background and the “myth of the frontier”, hardened over time. In later years, he ignored some of the caveats he set forth in his own monograph. But even his approach to reports from the 1930s reflected a set of beliefs about habitat requirements that had no scientific basis. Many people, myself included, are prone to reflexively accepting these assumptions about “habitat quality” because the conventional wisdom is so deeply engrained.

Fangsheath also reminded me that in the years before Tanner, the species was being written off and had been for decades. Florida was believed to be the last stronghold; the Singer Tract and Atchafalaya basin were not considered, nor were the large tracts of overcup oak/water hickory forest (where Beyer found ivorybills in 1898), many of which were untouched until the 1940s. Unlike the Singer Tract, these areas were often roadless and very difficult to penetrate; the Tract was bisected by a road, had few deep bayous, and was largely free of undergrowth, making it much easier to search. I’ve already discussed Tanner’s difficulty in finding ivorybills anywhere besides John’s Bayou. In this context, it’s worth noting that Bick’s 1941 sighting (from his car on Sharkey Road) involved two birds feeding in a lower lying “ash flat” in which overcup oak predominated.

In addition to these conceptual flaws, the papers grossly underestimate the number of post-Singer Tract encounters within the historic range. While it is impossible to quantify the controversial reports, it’s clear that the 26 or 29 referenced in the studies are the tip of the iceberg. There are well over four times that many on record for the 1944-2003 time period. And no doubt, numerous encounters never made it into the literature.

I initially posted a brief comment about this on Facebook and ibwo.net, with a link to Jerome Jackson’s 2002 Birdwatching Daily article listing 20 pre-Arkansas and post-Singer Tract encounters (some just auditory and one from Cuba) and a reference to Michael Steinberg’s Stalking the Ghost Bird catalogue of 85 sightings during the same time frame. A commenter wrote, “Yes but no confirming photos”. That also led me to think it would be worthwhile to explore this subject in a somewhat more depth, since there is physical evidence, albeit contested, related to several post-Singer Tract and pre-Arkansas reports.

Before turning to the physical evidence, it’s worth reiterating that the 1944 date for the last “verified sighting” is fundamentally flawed and arbitrary. The 1944 date is for the “Say Goodnight” encounter that involved artist Don Eckelberry and two local boys, Billy and Bobby Fought, and the purported last lone female IBWO in the Singer Tract. This poignant story was retold in The Race to Save the Lord God Bird, and it has become central to the popular lore about the species. There’s no doubt that the encounter took place, and Eckelberry no doubt believed that the bird was the last of her kind. Roger Tory Peterson apparently received and accepted a report that a single bird, presumably the same one, was still present in 1946. Tanner was likely aware of this and had an additional reason to think that birds persisted in the Tract well after 1944. His papers include a letter stating that Singer Tract game warden Gus Willett saw a pair in November 1948 at North Lake #1 (I have been unable to identify this lake). According to the letter, the “[b]irds are moving over a much larger area than formerly.” The letter mentions that there had been several other sightings during this time period. There’s no reply from Tanner in the archives and no further correspondence about the Singer  Tract birds. It appears that this is the letter from Tanner’s former student, Arthur MacMurray, that is referenced in Jackson, but Jackson’s account does not mention Willett, who would have been familiar with ivorybills. The strong possibility that a pair of birds remained in the Tract for more than four years after it was cut should itself raise questions about Tanner’s narrative.

Jackson’s list of 19 US reports between 1944 and 2003 was undoubtedly not intended to be comprehensive (and his book includes many others). Instead, it focuses on sightings by professional ornithologists and/or people who were familiar with the species. These include: Allan Cruickshank, John Terres, Herbert Stoddard, John Dennis, Davis Crompton (Dennis and Crompton studied ivorybills in Cuba), Whitney Eastman, and William Rhein. Jackson doesn’t mention it, and was perhaps unaware when he wrote the article, but Rhein had filmed the Imperial Woodpecker in Mexico several years prior to his 1959 Florida ivorybill sighting. It strains credulity to think that every one of these experienced observers, most or all of whom were familiar with the species and all of whom knew pileateds well, would be mistaken. Jackson points out that Terres kept his sighting to himself for more than 30 years out of “fear of being scorned.” Such was the climate surrounding ivorybill claims, even in 1955.

Steinberg lists 85 sightings between 1944 and 2003. His list includes most, if not all, of Jackson’s reports, breaking them down into individual incidents. Jackson treated repeat encounters in the aggregate. Nonetheless, most of Steinberg’s reports do not appear on Jackson’s list. Many of them are from less illustrious sources and quite a few are anonymous, but some of them are from game wardens, field biologists, and graduate students in ornithology.

The Ivory-billed Woodpecker Recovery Plan, prepared by the U.S. Fish and Wildlife Service and completed in 2010, includes an even more detailed compilation of records, some of which are of course also included in Jackson and Steinberg. It lists approximately 100 reports of varying quality between 1944 and 2003. Some of these are aggregates, involving multiple observations. The number of observations is sometimes enumerated and sometimes characterized as “numerous”, “multiple”, or “several”, so it’s impossible to arrive at an accurate tally, but the total almost certainly exceeds 150.

Although the Steinberg and the Recovery Plan compilations are more extensive, they are undoubtedly far from comprehensive. For starters, the climate of intimidation around reporting ivorybills was strong enough to deter John Terres in 1955, and that climate of intimidation only grew more toxic over time, as the Big Thicket and Fielding Lewis incidents, not to mention the battle over the Arkansas reports, make clear. In addition, there’s good reason to believe that countless reports from local people, hunters, and amateur birders have been discounted, dismissed, or ignored by authorities, at least prior to the “rediscovery”. Steinberg writes of his first visit to the Louisiana Department of Wildlife and Fisheries Baton Rouge office in 2003,“ . . . few people took the book, or more important the larger issue very seriously. The typical response from many in the office, other than Nancy Higginbotham, seemed to be, ‘Don’t you have anything better to do?’” (Higginbotham claimed two sightings, one of male in 1986 and one of a female in 1987, both in the Pearl River area.) We’re personally familiar with several instances in which reports were dismissed or ignored. One involved the landowner in our old search area, who came forward after the Kulivan sighting and was deeply offended by the way he was treated. As far as I’m aware, no one has done a comprehensive review of records committee submittals within the historic range of the ivorybill; I know of one such submittal from Texas in 2002 that came from unsuitable habitat, outside the historic range, but there may well be others that are more robust.

I’d like to turn to three examples of physical evidence obtained in the post-1944 era. Some of this is fairly well known – the Agey and Heinzmann feather and the Fielding Lewis photographs. The other is somewhat more obscure, but no less interesting for being so.

The Agey and Heinzmann observations took place between 1967 and 1969, in Polk County Florida. They obtained two recordings that Tanner dismissed. There was evidently some very poor communication about it that was compounded by an obvious error on Agey and Heinzmann’s part. They mistakenly thought that calls on their first clip were consistent with some ivorybill sounds from the Singer Tract; they clearly are not. The second clip, which is dominated by a Red-shouldered Hawk, recorded March 3 1968, does have some faint kent-like sounds, but the quality is extremely poor. They are most easily heard on the amplified version that begins at 3:14. The RSHA calls were not what interested Agey and Heinzmann, but they failed to make this sufficiently clear.

I believe Tanner wrote the notes that accompany the recording:

“Well, I’m not sure what to say here. As far as I can determine, there are only four original sound clips here. The recordings at 0:04-0:32 and 0:49-0:57 are certainly flicker-like, especially the continuous series at 0:04-0:21 and 0:26-0:32, but I am less certain about the latter part of the first series (0:21-0:23), which appears to have been recopied twice at 0:41-0:48. A similar vocalization is included at 0:49-0:57 (recopied at 0:59-1:06). Given the very different quality of these sounds relative to those in LNS #6784, combined with the close similarity of the calls to those of Colatpes auratus, leads me to doubt that any of these sounds were given by C. principalis. The recordings from 3 March 1968 (2:45-3:07) represent the calls of Buteo lineatus. Quality unchanged (2;3 – the signal is not bad for the first part, but terrible for the rest, most of which seems to represent copies of various recordings)”

Agey and Heinzmann found several feathers near a cavity, and one was identified as the innermost secondary of an Ivory-billed Woodpecker. Oddly, Jackson wrote that “ . . . some shadow of doubt is cast over these records because Agey and Heinzmann also tape-recorded what they said were Ivory-billed Woodpeckers, and personnel at the Cornell Laboratory of Ornithology identified the birds on those tapes as pileated woodpeckers.” Given that one of the recordings does include kent-like calls, this criticism is not entirely warranted, and the misidentification seems irrelevant in light of the physical evidence (and ironically Tanner seems to have failed to correctly identify the calls on the first clip). Jackson also alludes indirectly to rumors that the feathers were taken from a specimen. These have circulated for years but are unsubstantiated. Agey and Heinzmann published their findings:

Agey, H. N., and G. M. Heinzmann. 1971a. The Ivory-billed Woodpecker found in central Florida. Fla. Nat. 44 (3):46–47, 64.

Agey, H. N., and G. M. Heinzmann. 1971b. Ivory-billed Woodpeckers in Florida. Birding 3:43.

To the best of my knowledge neither publication is available online at this time.

The next event, chronologically, started with a series of encounters in east Texas in the late 1960s. John Dennis obtained a recording that Tanner initially dismissed, in part for the patently absurd reason that a Pine Warbler is also heard on the clip, but later described as “a real mystery” when confronted with the sonograms and analysis that were suggestive of ivorybill. That recording is now catalogued as IBWO.

Additional slides, taken in 1970 in east Texas by a man named Neal Wright, were turned over to the Museum of Natural History in Philadelphia which also houses the Fielding Lewis photographs. These were made public after the rediscovery, and since writing this in 2015, I obtained permission to post them on the blog. They show what appears to be a female Ivory-billed Woodpecker in a nest cavity. When I first viewed the Wright photographs, I was quite skeptical, but later, I was struck by the resemblance to this image from the Singer Tract.

Wright was apparently quite a local character, and I remain somewhat suspicious, as he may have had ulterior motives; however, the similarity to one of the unpublished images from the Singer Tract is strong, and in the pre-internet era, it seems unlikely that a Texas woodsman would be familiar with any of the ivorybill images that did not appear in Tanner’s monograph.

The Fielding Lewis photographs, taken in South Louisiana in 1971, are far better known, although Lewis wished to remain anonymous. His identity was not revealed until more than three decades later, and he was identified at the time only as “the Chief” (Jackson was unaware of his identity in 2004, though it was made public soon thereafter.) George Lowery presented these images at the American Ornithologists’ Union annual meeting and was attacked by many of his colleagues who deemed them to be a hoax. It’s worth pointing out that there have been hoaxes in recent years (these were swiftly and easily debunked), so there’s legitimate reason for skepticism about any claim. In the case of the ivorybill, however, skepticism has frequently been replaced by a virtually irrebuttable presumption of fraud (or error).

In a letter to Tanner, Lowery (who, unlike most of his detractors, had actual field knowledge of ivorybills) wrote: “I know the man in question very well and I am sure he would not pull something like that. In the first place, where would he have gotten the mounted specimen? Why would he have two photographs of the birds way up on two separate trees? Both of considerable diameter and not subject to being shinnied. Also, assuming he might have had a mounted bird to photograph, why didn’t he get a better picture while he was at it?”

The most common reasons given for believing that Lewis hoaxed the photos are that the bird is similarly positioned in both images (similarly but not identically, a neat trick with a specimen) and that the bill and feet are not visible. Bear in mind that these pictures were taken with a Brownie or Instamatic camera, and the quality is very poor. Nonetheless, I believe a foot is very faintly visible in both photos, positioned in a manner that would be expected of a live Campephilus woodpecker. I worked from scans of the originals and made some modest enhancements in Photoshop. Note also that in the first picture, both a cavity and bark scaling can be seen on the tree.

fieldle1-enlarg-scan copylewisphotoarrow

Regardless of whether my analysis is correct, the foundation for claiming that these photographs were faked is shaky indeed – not only for the reasons Lowery gave but also because of Lewis’s reticence about revealing his identity, insistence on keeping the location secret, and lack of any discernible motive.

The recovery plan mentions two other pieces of physical evidence. One is a feather that was purportedly found in a nest or roost cavity in 1985, and the other is a photograph supposedly taken in Georgia in 1975 (correction, 1965).

It’s not my intention to fault the IUCN or to quarrel with the “possibly extinct” designation, although I think Bill Pulliam’s analysis of the Luneau video in light of Rhein’s Imperial Woodpecker film should be dispositive. My main purpose is to call attention to the fact that there’s considerably more evidence for survival than is popularly recognized or than appears in the scientific literature. There are multiple instances of people, often outstanding birders, hesitating to come forward with reports and hard evidence – for decades. Terres waited 30 years; in the cases involving physical evidence, only Agey and Heinzmann went fully public and identified themselves in making their claims; in Stalking the Ghost Bird, Steinberg includes detailed 2005 field notes written by a Louisiana “birder for more than forty years” who “has also worked as a contract ornithologist conducting bird surveys on rice and crawfish farms for more than ten years.” This individual too requested anonymity. To a significant extent, the shortcomings in the literature are directly related to the controversy that has surrounded this species for nearly a century (remember Mason Spencer who went so far as to obtain a permit and kill an ivorybill to prove the species persisted) and the accompanying climate of unhealthy skepticism that has, if anything, grown even more unhealthy since the rediscovery. This sets the ivorybill apart from other possibly extinct species.

I’ll be heading for Louisiana at the end of the week and will post a trip report when I return.


In Which Someone Proposes Red-breasted Nuthatch for the March Calls

Someone recently proposed Red-breasted Nuthatch as the source of the March calls and pointed me to this clip.

It’s worth listening to the recording in tandem with some of our putative ivorybill calls. The pitches do sound close.

The habitat isn’t really right for Red-breasted Nuthatch. I’ve never encountered any in the search area, even during irruptions, and the area from which the calls were coming has no conifers. The two calls I heard did not sound like nuthatches to me, and Matt Courtman, who knows the species well, categorically rules out nuthatch of any kind. Nevertheless, I took the opportunity to revisit the sonograms and listen to a whole lot of nuthatch calls.

There’s definitely a similarity, but I’d describe the Red-breasted Nuthatch calls as being buzzier in quality. The harmonics are dramatically different, which accounts for the difference in sound.

For those unfamiliar with sonograms, the X axis is time (in seconds) and the Y axis is frequency.

Red-breasted Nuthatch toots consistently have a fundamental frequency of around 1000 hz; most of our recorded calls have a fundamental that’s closer to 500-600. The strongest emphasis in our calls is on the third partial, usually between 1600-1900 hz. Most of the emphasis in the RBNU calls is on the fourth and fifth partials, in the 2500-3500 hz range; these partials, when visible, are much weaker in our putative ivorybill recordings.

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Typical Red-breasted Nuthatch sonogram. Note the weak fundamental at over 1000 hz and the strong 4th and 5th partials.

 

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Putative Ivory-billed Woodpecker recording, March 15, 2017. Three calls are visible to the left of the white vertical line. Note the stronger fundamental frequency at around 500-600 hz, the weaker second partial, the strong third, and faint, weaker higher partials.

Finally, for reference, it’s worth checking out the White-breasted Nuthatch, both the call and the sonogram. As discussed in a previous post, White-breasted Nuthatches are present in the area, and a number of their faint calls are captured on the recording.

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White-breasted Nuthatch sonogram, showing a weak first partial at approximately 1000hz, strong second and third partials, and somewhat weaker fourths.

In an earlier post, I mentioned that Tanner suggested that ivorybill calls were more like Red-breasted Nuthatches, while Hasbrouck described them as being “exactly like the note of the White-breasted Nuthatch”. I’m still on a learning curve when it comes to bioacoustics, but the harmonic structure of White-breasted call seems closer to known ivorybill calls than is the call of the Red-breasted.

The difference in tonal quality that was apparent to my ears is explained very succinctly on the Earbirding blog:

All nasal sounds are stacks of partials, but not all stacks of partials sound nasal. The tone quality of a complex sound depends on which partials are loudest—that is, darkest on the spectrogram.

The higher the darkest line in a stack, the more nasal the sound.

Known ivorybill calls have a strong 3rd partial and are on the less nasal side of the nasal spectrum; the strength of the 3rd partial became more apparent when the Singer Tract calls were played back and recorded at a distance of 145 meters. Red-breasted Nuthatch calls with their strong 4th and 5th partials are considerably more nasal. The White-breasted falls in between, with strong 3rd and 4th partials.

Tanner wrote that the calls of the ivorybill are “much longer and pitched higher than the White-breasted Nuthatch” and “are more in the range of the Red-breasted Nuthatch”. To reiterate a point made previously, this suggests that typical “kents” were of considerably longer duration than the calls on the Singer Tract recordings, as is the case with the calls Phil and Matt recorded in March. This is important to note, since Cornell, following the Singer Tract recordings, has assumed a duration of 60-100 milliseconds for ivorybill kents, whereas kent-like Red-breasted Nuthatch calls are much longer, often upwards of 300 ms, and White-breasteds seem to be in the 100-200 ms range. One outside reviewer provided durations for eight of the calls we recorded, and they vary considerably, from ~80 ms to ~350 ms.

Whatever these mystery sounds may have been, I’m sure they’re not Red-breasted Nuthatch. They’re not White-breasted Nuthatch either. Nor are they a good match for Blue Jay or Turkey. Carefully considered, serious suggestions are welcome.


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.

GoogleEarth_Image

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