Trip Report, March 5-17, 2019

The following trip report is mostly extracted from a post for members of the search team.

I was in the field from March 5-17; others were around before and after. Thanks to the whole team and a couple of guests for their hard work and contributions in the field this trip. We completed the swap out of recording devices in three days, which left a lot of field time afterwards. We were very fortunate in that only one unit was tampered with and only a couple malfunctioned. This is a very low rate of loss for these units.

We continue to have possible encounters in the area, perhaps at a higher rate than in past seasons, though the number of potential observers and time spent in the area has increased this year. And we have gotten some very preliminary results from the first round of deployments.

In addition to the audio deployments, we’re focused on obtaining DNA this season and have been refining the protocol for doing so. On this trip we collected samples from a couple of different forms of feeding sign, one I think is more promising than the other.

Here’s the basic protocol: collect a small quantity of material from places where a woodpecker’s tongue may have been; place it in a vial containing buffer and seal. With luck, genetic material can be obtained from these surfaces, and we can rule in or rule out ivorybill as the source of some kinds of feeding sign.

We also plan to collect samples from the most promising cavities. And are evaluating them following Cornell’s criteria. Cavities are graded:

A: very large cavity in size range of IBWO with irregular oval or rectangular shape (4.0–4.75in [10.2–12.1cm] wide and 5.0– 5.75in [12.7–14.6cm] tall);

B:  cavity larger than typical PIWO cavity but shape is fairly regular, nearly perfect round or oval; or, cavity of irregular shape and within upper size range for PIWO, and lower size range for IBWO (3.5in x 3.7in or [8.8cm x 9.5cm] large PIWO and 4.0in x 5.0in [10.1cm x 12.8cm] small IBWO);

C:  cavity of fairly regular shape, nearly perfect oval or round, in the upper size range for PIWO and lower size range for IBWO. Same dimensions as for B.

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Ivory-billed Woodpecker Cavity (1935 Nest)
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Typical Pileated Woodpecker Cavity

Here are some promising cavities (I’d grade all of them A or high B) I found last trip, plus some we know are being used by other species. I found more cavities this trip than I ever have in the past, mostly because I was paying attention. There’ll be some explanation in the captions. The truth is, no one really knows about cavities; I’ve seen a lot of variation in what PIWOs do; so a lot of this is speculation. I do think scaling or suggestive feeding sign on a tree with a cavity in it may be an indicator, including that the cavity is a former nest.

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Promising cavity, apparently recent

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Promising cavity with a little fresh scaling; however, there were Wood Ducks perched in this tree, which suggests that it may no longer be active.

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Cavities are harder to spot after leaf out. This one looks fairly fresh.

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Older large cavity in cypress stub.

It can be a tough call. The first pair of cavities shown below is being used (and was likely excavated by) Red-bellied Woodpeckers. The size is deceptively large, but the small diameter of the high limb is an indicator.

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The intriguing cavity below was being used as a PIWO roost but would probably have been graded A for its large size and irregular shape. There’s a second, possibly connected, cavity slightly higher and to the the left. Both are oddly shaped. The snag is severely decayed. But again, we have very limited information, so there’s no way to know whether IBWOs might avoid badly decayed snags.

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Regarding feeding sign, extensive scaling on boles, especially of mature trees with tight bark, seems likeliest for Ivory-billed Woodpecker work. Hickories are the highest priority within this category, and we have only found a few such trees over the years. Extensively scaled sweet gums, like the one shown, are worth noting too. A second category, involving smaller sweet gums and branches, is also intriguing. Ambrosia beetles are the prey species involved in this work, which involves extensive stripping and targeted digs into the insect chambers.

In all cases, it’s important to distinguish scaling from shallow excavation with associated bark removal.

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Suspected IBWO hickory chips

The appearance of this work is distinctive. The bark is removed cleanly, and there’s almost no damage to the underlying wood, except for expansion of the exit tunnels on the surface. We hope that DNA can be extracted from these tunnels and that the scaling shown in the first image is fresh enough to be a good candidate. Based on the life-cycle of the beetles involved, I suspect this work is likelier to be found in the latter part of spring and through summer, but keep your eyes open anyway.

We’re finding that Pileateds also feed on hickories and begin by removing bark. They go about it in a different way, however, excavating through the bark and into the sapwood. The appearance of Pileated work on hickories is similar but somewhat different. It tends to be patchier, without less extensive and contiguous bark removal. The chips are smaller, a mix of bark and sapwood, and the appearance of the wood in the areas where bark has been removed is distinctly different, as in the images below.

Extensive scaling on boles of other species is also noteworthy and may have DNA collection potential. There’s more room for overlap between what IBWO and what PIWO might be able to do, since the properties of hickory bark are unique. Look for extensiveness, large to enormous chips, and lack of damage to the underlying wood.

The final category involves sweet gum saplings and small to medium-sized limbs. I have found this distinctive appearing work in only two years, in a small cluster in 2015 and in a single example this season. The bark is extensively, indeed almost entirely, stripped. Chips on the ground should be large. Leaves should be still attached. The beetles’ brood chambers should have been vigorously attacked, and you may see superficial horizontal scratches in the sapwood (not the deeper grooves that used to be mistakenly ascribed to IBWO).

This was a longer trip than usual, and I was wiped out when I got home. We will be returning at the end of April to collect the units. This will mark the end of the deployments for this season, though we will continue to work with the trail cams, with a couple transferred to new locations. I’m hoping to have a guest post from a team member before the next trip.


Old Singer Tract Images Compared with Two More Recent Ones (from Elsewhere)

1967 slides taken by Neal Wright of a putative Ivory-billed Woodpecker in Texas are viewable on Vireo (search Ivory-billed Woodpecker), but high resolution scans have not been widely circulated as far as I know. These images were not made public until after the the Arkansas “rediscovery”, more than three decades after they were obtained. Wright’s story is mentioned in Jackson (2004) “Reynard saw the photo and said that it was fuzzy but definitely of a Campephilus woodpecker.” It’s clear from the context that Jackson had not seen the images at the time of writing.

When I first encountered the Wright slides, I was skeptical, but after seeing some lesser-known Singer Tract photographs as well as other images of Campephilus woodpeckers in cavities, my opinion started to shift. After finding additional ivorybill photographs in the Cornell archives and in Tanner’s dissertation, I thought it would be worth posting some of those images along with one of Wright’s slides for the sake of comparison.

Of course, it’s up to readers to draw their own conclusions, but I think a few things are worthy of note. First, the Wright slides were taken long before the internet, at a time when the only readily available image of an ivorybill in a nest cavity was Tanner’s Plate 1, which is quite similar to Fig. 43b (below). The posture of Wright’s bird is much closer to the ones shown in the then virtually unknown and/or unpublished images, especially those from the 1938 nest. The placement of the cavity is also strikingly similar, just below a major fork. It seems highly unlikely that Wright would have been aware of obscure Singer Tract photographs.

While the image quality is too poor to be certain, there appears to be excavation similar to work found on some Singer Tract nest and roost trees to the right of the nest cavity in Wright’s slide. Again, this is a fine detail that would likely have been unknown to Wright and that would have been difficult to fabricate.

These are very poor quality images; the malar stripe seems a little too extensive, although this could easily be a function of angle and lighting. As with the Fielding Lewis photographs, which were taken several years later, I have to wonder why anyone intent on committing a hoax wouldn’t do a better job. And in the case of the Wright pictures, it would make more sense if the template for such a hoax would have been Plate 1 in Tanner, rather than photos that were unknown to all but a handful of people, most of them at a northeastern university.

Finally, I think the fact that the images were turned over to an ornithologist (George Reynard, scroll down for his obituary) but were kept confidential for so long also tends to support the idea that they’re authentic. Neal Wright may have had an agenda – a desire to protect the area where he took the picture – but the images were not used to serve that purpose.

Edited to add: This fascinating article on a recent, non-ivorybill related hoax suggests that it’s not uncommon for hoaxes to be paradoxically uneven in quality, and that hoaxers’ motives can be murky and bizarre. Nonetheless, I think that other factors point to authenticity for both the Wright and Lewis photos.

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© N. Wright/VIREO USA – Nest with adult protruding, slide mount dated 5/70 (apparently the duplication date). Poorly defined bird is apparently peering out of a cavity in the upper left of the trunk, below the fork.

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Ivorybills at Nest, John’s Bayou 1938, female’s head protruding from cavity

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Ivorybills at Nest, John’s Bayou, 1935, male’s head protruding from cavity


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Images from the Singer Tract and James T. Tanner’s Dissertation Courtesy of Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library


Another item I found in Tanner’s dissertation merits comparison with one of Project Coyote’s camera trap photos, since the tree species involved are the same. Plate 7 in Tanner shows ivorybill feeding sign on honey locusts, but the reproduction in the monograph is very dark. The figure from the dissertation is much brighter, making it clearer what Tanner was attempting to show. I think the similarity to the work on our target tree, where I had a sighting a week prior to the capture, is striking.

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Courtesy of the Rare and Manuscript Division, Cornell University Libraries

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Trail cam photo with scaled tree in the foreground and suspected female Ivory-billed Woodpecker in red box, Nov. 2009

To enlarge the trail cam photo, click here.

Rare Ivory-billed Woodpecker Images



My visits to Cornell’s Kroch Library, where the Rare and Manuscript Collections are housed, have been very productive. In addition to the last letter to Tanner pertaining to the Singer Tract ivorybills quoted at length here, I’ve come across several little known ivorybill images, some better quality reproductions of the plates in Tanner, and some additional hints about ivorybill foraging excavations that I’ll discuss in a future post. I suspect that all of the images below are actually stills from the 1935 film footage that has been lost save for a few minutes. To see it, go here and start at 14:00. To the best of my knowledge, these images have not previously been published as stills, and a couple of the frames may never have been publicly available.

The first image is similar to the one that appears on Page 82 0f  The Race to Save the Lord God Bird.  This is a sequence (that apparently has been lost) in which the birds are changing places on the nest. A third image that follows the first two appears on p. 120 of The Race . . . A colorized version, at once gorgeous and crude and sadly somewhat damaged, is also included here; it’s reproduced in black and white in Jackson (p. 27).

I think the bird in the remaining frames is the male. In the second frame, he may be engaging in the motion described by Tanner, “. . . jerking as though working food from the back of its mouth.” the next frame shows the him peering into the cavity. These two images are clips from the surviving footage. The final shot may have come from a lost piece of film, since a remaining clip, filmed from a similar angle doesn’t include it.

In addition to the images posted below, two figures in Tanner’s dissertation include unpublished photos from 1938 – one of a male at the nest cavity and the other of a juvenile peering out of it. Those images may also be included in a future post. All four pictures below were taken with my iPhone. I have a high resolution scan of the fourth on order, since it is one of the best representations of presumed ivorybill excavation available. Images are Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library.



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Habitat Conditions in the Singer Tract

Late last year, I wrote a post entitled “More Minutiae – Habitat Quality and Population Density in the Singer Tract”. I had to follow up with a couple of corrections and elaborations based on insights others shared with me. In the interest of providing more clarity and coherence, I thought I’d do a new piece combining the three posts and expanding on them a bit. I won’t delete the originals, but this one reflects what I think is a more accurate understanding of the material involved.

Mack's Bayou Ivorybill nest tree. Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library

Mack’s Bayou nest tree. Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library

The initial post was inspired by the image above and the caption describing it as the “Third ivorybills’ nest”, one I had looked at but not closely until last year. When I did examine it carefully, I was struck by how open the surrounding area seemed to be. Then I started going through archival photographs and scrutinizing them a little more closely.

In browsing through the Louisiana Digital Library’s collection of Singer Tract photographs, I came across an image that I had missed, one of the bridge over John’s Bayou taken in 1940. Tanner (p.32) includes an ivorybill sighting from this immediate vicinity, just northwest of the bridge. What I find interesting about the photograph is that the forest along the road appears to be fairly even-aged and does not have the characteristics typically associated with old growth. It is similar to what can be found in many parts of Louisiana today. An image from along Sharkey Road taken in 1937 shows similar characteristics, although another shot from 1939 (probably taken east of the bridge) shows more impressive looking habitat.

Richard Pough wrote a follow-up report to the Audubon Society on the Singer Tract in 1944. It’s a very interesting document that raises some questions about Tanner’s work. Pough explicitly accepted “Tanner’s premises as to the feeding habits and habitat preferences of the ivory-bill”, but he also noted “[n]othing in Mr. Tanner’s study indicates that Ivory-billed Woodpeckers show any preference or marked dependence on trees of great size such as one would find only in a virgin forest. He found them doing 14% of their feeding on trees 3”-12” in diameter and 64% on trees under 24” in diameter.”

Pough pointed out that “Maps of the area as of 1846 showed much of the Tensas River in plantations and many cleared fields back from the river on some of the interior ridges. This development continued for another 20 years until the Civil War, by which time Madison Parish was producing 110,000 bales of cotton a year. As the Parish has never produced over 30,000 bales since the Civil War, one gets some idea of how much land is now occupied by second growth forest of approximately 80 years age.”

Pough found only one ivorybill, a female. He assumed, relying on Tanner, that this was the only one left in the Tract. He may well have been mistaken, since Gus Willett, game warden in the Tract, wrote Tanner about seeing a pair in November 1948 (although the exact location is unclear). Correction, Willett did not write the letter, although the report reached Tanner, as discussed here.

The lone bird Pough saw was either the John’s Bayou female or one of its offspring. According to Pough, this bird was probably not feeding in virgin forest, and his report specifically suggests that Tanner might have been mistaken about the maturity of some of the habitat in the John’s Bayou area. In 1941, Tanner had written that the remaining John’s Bayou birds were roosting and feeding in “virgin” timber. Pough’s description of this area (and it seems to be the same patch) suggests it was likely cultivated pre-Civil War. It was devoid of big sweet gums, which Pough deemed to be the best indicator of old growth conditions, but had many dying Nuttall oaks 12-20 inches in diameter. Nonetheless, Pough relied on  Tanner’s premises to conclude that “only a relatively small portion of the total area of the Singer Tract supported a forest suitable as habitat for these birds.”

To return to the material in the earlier blog posts, much of the discussion focused on home ranges and the distribution of nest sites.

This map, drawn by Tanner after the 1935 expedition, lists three nests – designated as nests II, III, and IV –within a mile or two of each other and in the vicinity of John’s Bayou. Nest II is the famous “Elm Rock” nest. The map also shows a tree which is designated “Nest (?) III Squirrel” (also mentioned in Bales, “two miles to the south of the first nest” and fifty feet up p. 45). This was outside the area Tanner designated as prime in 1941 (p. 91); it is approximately a half-mile from the John’s Bayou bridge.

I’ve discussed this issue in depth with someone who’s very familiar with Tanner’s notes. I’m now persuaded Tanner concluded that nests III and IV from 1935 were not nests after all and that he assigned the birds involved to Titepaper (Nest III) and Bayou Despair (Nest IV). Nest IV is apparently one that Kuhn found but was unable to re-locate. Why Tanner changed his mind about it remains a mystery.

It’s very difficult to piece together this fragmentary information, and the monograph muddies the waters a bit by presenting the home ranges of the birds as being quite discreet, perhaps a good deal more than they were in fact. I suspect that Tanner decided the cavities were actually roosts, (although neither one is mentioned in the monograph). If so, they would have been well outside the home ranges Tanner identified and closer to the core of the John’s Bayou range than to the core of Titepaper or Bayou Despair.

Nests I and V were located near Mack’s Bayou. Nest I is dated May 14, ’34 on the map, and Nest V is dated May 10, ’35. The ’35 nest failed. It is the one referenced above. Allen and Kellogg described it as being 45’ feet up, in a pin oak snag, in a natural clearing, although it has been suggested that the snag may have been a remnant large tree in area that had been cleared prior to the Civil War. The nest designated Nest I and dated May 14, 1934 appears to be the one Tanner described on p. 81 of the monograph, “located within 100 yards of the second nest found in 1935”; however, in the monograph, he gave the date as May 13, 1933.

It’s worth pointing out that the Mack’s Bayou nests were in an area that Tanner designated as “best” for ivory bills (even if it’s not clear whether it was truly old growth). Nonetheless, nests failed in 1933 and 1935, and the adult birds had disappeared by 1938, apparently after producing one fledgling in 1936 or 1937. This was before the logging began.

My intention in writing those initial posts was to get a clearer handle on population densities and habitat requirements in the Singer Tract. In retrospect, I’m not sure that’s possible, since Tanner’s observations were almost entirely limited to one family of birds in a population that was dwindling for unknown reasons. At the very least, Tanner’s statement that 7 pairs of birds required 120 square miles of virgin forest in 1934 is based on an inflated estimate of the amount of old growth in the Tract and his minimum estimate of 6.25 square miles per pair also rests on that flawed premise.

Pough observed, “ . . . the ivorybill problem puzzles me exceedingly, and I do not feel that Tanner’s report begins to explain the reasons for the drastic decline in this species.” As the 2014-2015 search season approaches, I can only hope that the question of how the species persisted will puzzle people exceedingly in future years.

Cavities and Context

As many readers of this blog are aware, I’ve been actively searching for ivorybills since 2007 and have been obsessed with foraging sign and cavities since my first days in the field. Over the years, I’ve looked at bark scaling and cavities both in and out of suspected ivorybill territory and have developed and refined a hypothesis about what constitutes diagnostic ivorybill foraging sign. I have come to believe that no such diagnostic category exists for nest or roost cavities, although size, shape, and other contextual elements can support a suspicion that a given cavity is an ivorybill nest or roost.

The cavity cluster we found in May 2014 has characteristics that are encouraging – size, shape, tree species, bark scaling in the vicinity – and one of the cavities resembles a known Ivory-billed Woodpecker nest. This is more than ample reason to survey the surrounding area very carefully (and I’m eager to get back out there), but whereas I feel personally confident that the dramatically scaled hardwoods in our search area were fed on by IBWOs, the mere presence of intriguing cavities is nowhere near as compelling for me.

Similarly, while I suspect that Frank Wiley found a recent nest and at least a couple of roost holes in our old search area, this view is informed more by the associated conditions than by the qualities of the cavities themselves. The suspected nest was in a tree that was heavily scaled and excavated in a way that was strikingly similar to a nest tree found in the Singer Tract, and this is more important than the size and shape of the cavity itself. The two suspected roost holes were in close proximity to one another, and were certainly large enough, but were dramatically different in appearance. There are several facts that are more significant than size or shape. We had a camera trap that covered both trees for a period of several months, and no Pileated Woodpeckers were photographed using the trees in question; the only image we obtained was suggestive of ivorybill but inconclusive (no images of either species were obtained from the suspected former nest tree, even though there were active PIWO roost cavities within 20 or 30 yards); in addition, we found an abundance of feeding sign in the area and had multiple auditory encounters and possible sightings within a few hundred yards of the suspected roosts between August 2009 and April 2010.


cavity 2 reportWillow Cavities, East-Central Louisiana 2009. Photos by Frank Wiley.

In examining the images of the suspected roosts and comparing them with other images of woodpecker cavities, I came across a photograph of a Crimson-crested Woodpecker (Campephilus melaneoleucos) near a cavity and was struck by the fact that it was almost identical in appearance to one of our suspected roost holes. I did some further research and found an image of a Pileated Woodpecker nest that was quite similar, if not quite as close a match.

All of this leads me to think that, while it’s important to look for suggestive cavities, this should not be the top priority. I’d encourage other searchers to focus on feeding sign, habitat characteristics, and local reports above all. The limited available information suggests that feeding sign is what led Allen and Kellogg to the Singer Tract birds and that it’s what Kuhn and Tanner looked for. Pileateds will use big cavities (and I’ve even seen White-breasted Nuthatches nesting in holes that look perfect for ivory bills). While finding a nesting or roosting ground will be central to documenting the ivorybill if it persists, cavities alone will not point the way.

Cavity Comparison

In late 2011, I visited the Museum of Natural History at Harvard and took some iPhone photos of the Ivory-billed Woodpecker nest that’s on display there. In reviewing the pictures of cavities I took last week in Louisiana, I was struck by the similarity in appearance, especially between the Harvard cavity and the cavity in the stack, the most significant difference is in orientation; one angles left and the other right. I’ve cropped and zoomed the Louisiana cavity, while boosting the contrast and details, and I’ve flipped the Harvard cavity so the orientation is the same.  ImageImage


The Louisiana cavity could, of course, have been gnawed by squirrels, but the similarity is intriguing.

Edited to add: while I believe there is a type of feeding sign that is diagnostic for IBWO, cavities are another matter. In my view, ivorybill-ish cavities only become interesting when associated with other indicators, especially feeding sign.

IBWO Minutiae for the Holidays

In searching Cornell University’s online digital archives, I ran across some IBWO related photographs from the 1935 Allen/Kellogg/Tanner expedition in the Albert Rich Brand collection. Many of these pictures are familiar and have been widely published. Others are likely to be new, even to the most obsessive researchers, since Brand was a relatively less celebrated member of the expedition. One of the more interesting images shows a nest cavity near the top of a very long dead pin oak. This appears to be one of the two nest trees found by Allen and Kellogg and listed and discussed by Tanner, pp. 67-70. The typewritten caption on the photograph reads “The third Ivorybill’s nest. . .”, although Tanner only mentions two. The quality of the photograph is poor, but it is interesting because the stub is clearly long dead.

For my purposes, the most interesting photograph, titled Rock Elm Observation Blind shows the better known nest tree (a maple) from a different perspective than the published photos and includes more of the trunk than the others I’ve seen. I downloaded the image, and enlarged it as best I could. Readers can do the same. On close examination, a bill is visible protruding from nest cavity, making this a modest addition to the body of ivorybill photographs. What I find most significant is the appearance of the scaling on the bole. While the condition of the underlying wood seems to be considerably worse than what we are deeming to be grade A scaling, the similarity in appearance is dramatic, especially on the edges. The resemblance between this work and the scaling found in July in the northern sector is particularly striking.

Edited to add: All the digitized Brand collection images are here. They’re worth a look.

In addition, I’ve found a hand tinted version of “Rock Elm Observation Blind” in the Arthur A. Allen collection, under the title “Ivory-billed Woodpecker – Blind at Nest“. Although the colors are slightly washed out and smeared, the bird in the cavity is a little easier to see, and the similarities between the scaling on that tree and the scaling we’re finding are a little more evident, at least to my eyes.


Wishing everyone the best for the holidays and the coming year!