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Trip Report: May 18-25, 2016

I don’t expect to return to our search area until sometime this fall, but I hope that my schedule will allow me to spend a lot more time in the field next season. Overall, this was a challenging week due to high temperatures and severe back pain that troubled me from the end of the first day on. Nonetheless, it was a productive trip, and weather conditions were generally tolerable – hot and humid but not unbearably so, with daytime temperatures mostly in the high 80s. Woodpeckers, except for Red-bellieds, were generally quiet and unobtrusive. The only Pileateds I saw were responding to playbacks, and while I didn’t keep count, I’d estimate I heard their vocalizations an average of 2 or 3 times a day.

In contrast to winter and early spring, the woods are filled with other sounds – songbirds, frogs, cicadas, squirrels – making it much harder to separate signal from noise. Green frog calls can sound a little like double knocks at a distance, especially if you’re walking, and the squirrel calls in this recording were intriguing enough to capture, as only the somewhat kent-like sounds were audible to me in the field, something for other searchers to bear in mind.

May 18

I had a 6 am flight out of JFK. After arriving in New Orleans, I met Frank Wiley for coffee and then drove to his house, changed clothes and got to the search area at a little after 2 pm. The area I visited is the one closest to a parish road. This is a part of the southern sector in which we’ve consistently found feeding sign since 2012 and where I found a number of recently scaled trees in March of this year. Despite full leaf out, I was able to find quite a few more recently scaled trees in the general vicinity of those discussed in the most recent trip report.

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Unfortunately, and perhaps because my attention was on looking for feeding sign, I got somewhat turned around and wandered considerably farther south than I had intended, running the risk not only of trespassing but also of getting stranded in the woods. I noticed this at about 6 pm. Fortunately, I wasn’t too far from the road, just well south of where I wanted to be. It took me a half hour to reach the road (at which point I noticed my back was hurting badly) and another ten minutes or so to get to the car. I didn’t sleep much or well that night, despite having been awake since 3:30 am.

May 19

My back continued to bother me, so I tried to take it easy by spending the morning in the most accessible part of the search area. I found a few additional scaled trees, some with old work and excavation that seems consistent with what Tanner described, others with scaling that looked fresh.

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May 20

Travis Lux, a radio freelancer working on an ivorybill story, spent the morning in the field with me. (Most days this week I could only manage being out from around 6 am – 1 pm.) We visited the northern sector. I did not find any new feeding trees.

We passed the large downed limb where we had a camera trap for some time, and there has been no fresh work on it since the flooding in March. And only a small quantity of bark has been removed since the camera was deployed.

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This may be significant, since it seems likely that common animals with small home ranges would return repeatedly to the same feeding spot. In the case of this limb, it seems to have been scaled by something unknown, prior to our camera deployment and again a little over a month later. Squirrels, Red-bellied, and Pileated Woodpeckers were captured or seen on the target limbs, but they did no scaling. As I’ve mentioned previously, in most instances, we’re finding that trees are visited by whatever’s scaling them once or sporadically over a period of months.

We continued southward into the area discussed in the last trip report; we’ve found feeding sign regularly in this small area every season since 2013-2014. I did not find any new feeding trees: however, there was additional scaling on a couple of the trees found in recent trips, most notably the large dying sweet gum below (the next to last image in the post). I’m hoping that Frank will be able to train a camera on this treetop once our old Reconyxes have been repaired. The resolution on our other cameras is too poor to aim them so high; the same may be true of the Reconyx cams, but the quality is somewhat better.

We did a stake out in the area for a couple of hours but did not see or hear anything of interest. On the way out, I noticed that one of our suspected feeding trees had some very fresh scaling on it. This is a small tree with thin bark, and the chips were mostly very small. I do not suspect this to be ivorybill work and have a hunch that it was done by a Hairy, taking advantage of scaling that had been begun by another species.

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May 20

I returned to the part our search area that’s most readily accessible from the road, so I was in the woods before sunrise. I found a few additional recently scaled trees, some with very large chips at the base. One of these was heavily scaled on the bole as well as on the branches, and although the bark was loose in some spots; it was tight in others. The presence of twigs and small branches suggests that it had died fairly recently, even though there were signs of Pileated Woodpecker excavation on decaying parts of the bole.

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May 21

Phil and Eric Vanbergen joined me, and we returned to the area I’d visited the day before, again getting into the woods early. We found a six more scaled trees, took GPS points, and measurements. The trees were all live or fairly freshly dead. All were sweet gums, as has been the case for virtually all trees found this season (with two possible exceptions, one of which is shown in the May 22nd entry). Diameters of the trees measured were 14.7”, 19”, 21”, 25.1”, 26.2”, and 27”

Four of the six trees listed above were found in pairs, about 5’ apart in one instance and 20’ apart in the other. In the case of one pair, a long dead sweet gum and a live hickory within 30’ also showed some older scaling. Most of this work was recent but not fresh. We found large chips at the base of the pair of trees that are 5’ feet apart; these were probably a few months old.

While I did not keep count, and we only took coordinates for a few of the trees found this time around, I’d estimate I found a total of 15-18 recently scaled sweet gums in and around the southern concentration described in the last trip report.

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May 22

The Vanbergens were along again. It’s refreshing to spend time in the woods with young people (Phil’s in college and Eric’s in high school) who know and love nature, something that seems to interest fewer and fewer people in their age group. They have suggested some interesting strategies for searching, and I’m looking forward to their participation next season.

We went to the northern area, arriving at the scaling concentration at around 7:30. We staked out feeding trees until around 10 with no results.

Here are some of Eric’s wonderful photos: cottonmouth, pale lobelia, bark scaling, swamp milkweed, and another cottonmouth. He identified the plants.

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After that we headed further south to an area they hadn’t visited before. We found a little bit of fairly recent scaling on a dead hickory about 20 yards from where I found a heavily scaled hickory in 2013. The scaling is not extensive; it’s clearly targeted at larger Cerambycids, but given the small patches, Hairy Woodpecker is a distinct possibility. I was unable to find any fresh chips, so the work is probably several months old.

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May 23

I returned to the northern area alone and spent the morning staking out the same large feeding tree. I watched Red-bellied Woodpeckers flying to and from the tree sporadically, usually spending very brief periods pecking and gleaning on both scaled and unscaled areas and drumming from time to time. At 7:30, the male landed at the top of scaled stub and called. The female arrived; they copulated, and she flew off. He departed a few seconds later. At 8:30, I recorded the squirrel calls, and at 10:35, one of the RBWOs landed near the top of the scaled stub, peered around at me, and eventually started to drum. I called it a day shortly after noon. Here’s another image of the sweet gum top I was staking out, to give a sense of how extensively scaled it is in the crown.

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I hiked out, following a rather circuitous route. A few hundred yards from the concentration, I found a recently dead sweet gum with a few small scaled patches but no extensive work. I think this is another indication that this scaling is not being done by a common, evenly distributed species. Work tends to appear in bunches, with scattered sporadic examples elsewhere, but in the two areas discussed in this post, bark scaling on deciduous trees has been abundant in concentrated locations, over several years, and is much harder to find and scattered outside of these “hot zones”.

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On the 24th, I drove to New Orleans, stopping in Lafayette for lunch and ivorybill talk with Wylie Barrow and Tommy Michot.

I realize this has been a very image-heavy post. I sometimes think it’s hard to convey the quantity and unusual nature of the bark scaling we’re finding in this area and hope this does a somewhat more effective job at making it clear than some previous efforts.

That’s all for this season. I’ll be doing some additional posts on old material as well as one on foraging sign concentrations and tree species in the weeks ahead. I may also upload a lot more images of feeding sign to Flickr for those (if any) who haven’t seen enough of it. And of course, if there’s anything to report from Louisiana, you’ll read it here. I hope that the insights and data that have emerged this season will guide us next year.

 

 

 

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Old Material, New Light: More from the Archives Part 2

In late December 2014, I wrote what I’ve described as a speculative post titled, “Is There a Way to Recognize Ivory-billed Woodpecker Excavation? In that post, I relied on Tanner’s Plate 11,

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Tanner’s Plate 11, “Dead hackberry, fed upon frequently by Ivory-bills”. Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library

a brief description from the monograph: “When Ivory-bills dig, they chisel into the sap and heartwood for borers like other woodpeckers, digging slightly conical holes that are usually circular in cross section (Plate 11)”, and online imagery showing the work of other Campephilus woodpeckers. Material found during my recent visits to Kroch library at Cornell lends some support to the ideas contained in that post, and so does T. Gilbert Pearson’s photograph of a tree that had been fed on by ivorybills. Holt:Pearson Tree

The archival material includes additional images of ivorybill excavation and a considerably more detailed description by Tanner in a document prepared for the Cuban search in the 1980s. The passage includes somewhat more detail on bark scaling than is found elsewhere, but more importantly it describes ivorybill excavations as “hard to distinguish from similar digging by the Red-bellied Woodpecker”.

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Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library

This description may seem counterintuitive to some. Despite my own writing to the effect that ivorybill morphology may lead the species to dig less efficiently than pileateds and my references to targeted digging, I still had an underlying assumption that the size of the bird would correlate with the size of the dig and that ivorybill excavation would often resemble the familiar large furrows dug by PIWOs. While a couple of the holes in Plate 11 and in Pearson’s photograph may well involve the merging of more than one dig, it appears that ivorybill excavations are usually more targeted and that large furrows are not typical.

Also of interest for multiple reasons, including the observation of birds scaling very small limbs and of one feeding 5′ from the ground, are Tanner’s field notes from April 3rd, 1937.

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Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library

I’ll let the remaining images of known and suspected ivorybill excavations speak for themselves and will conclude with a few from our search area that seem consistent with known ivorybill work. While I’m nowhere near as confident about this material as I am about scaling, I suspect that finding excavations that are consistent with what ivorybills are known to have done in conjunction with scaling is suggestive.

I hope this material will be useful for other searchers. All images from the Singer Tract below are courtesy of the Division of Rare and Manuscript Collections, Cornell University Library. Most of these images were published in Tanner’s dissertation but have not been widely disseminated.

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1935 Nest Tree, Red Maple

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1935 Nest Tree and Detail from a Different Perspective

And now some examples from our search area that resemble the existing images of known ivorybill excavation. This is not something I’ve focused on, so I’ve probably missed other examples.

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Image at bottom is a detail of the sweet gum snag above. I suspect that more than one species of woodpecker is involved.

There will be one or two more installments in this series, but the next post is likely to be a trip report, probably the last for this season.


Old Material, New Light: More from the Archives Part 1

I’m planning to do a few more posts drawing on material I’ve found in Kroch Library’s Rare and Manuscript Collection at Cornell. There may be an intervening post or two on  other topics.

While Tanner’s monograph is well-known, the reports he wrote for the Audubon Society at the end of each season are not publicly available, except in the archives. The contents of these reports call some conventional wisdom about the species into question.

First and perhaps least important, it seems to be commonly believed that the John’s Bayou birds were the only remaining ivorybills in the Singer Tract when Tanner visited in December 1941. They were indeed the only birds he saw, as noted in his report (the first document below); however, he found feeding sign in the Mack’s Bayou area and suggested that at least two more birds remained, one at Mack’s Bayou and another in Greenlea Bend. As I read the report, Tanner referenced Bick’s observation in August ’41 (discussed here), and the context suggests that he related it to the John’s Bayou family. Other interpretations are possible, including that this was another family group that was passing through the area, which would mean that the remaining 1941 population was even larger.

In Ghost Birds, Steven Lyn Bales provides a full accounting of Tanner’s population estimates, but earlier books by Hoose and Jackson gloss over the likely presence of the other birds. Hoose (p. 120) wrote that James and Nancy Tanner “maybe heard a third” at Mack’s Bayou. (The source of this information is not identified.) Jackson (p. 132) has Nancy Tanner seeing a male and a female in December 1941. Both Bales and Hoose are clear that she saw the pair in 1940; per Bales, the actual date was December 21.

While there’s no way of knowing whether the birds Bick saw were the John’s Bayou family, I suspect that they were. I also think it’s reasonable to infer, as Tanner did, that this group bred successfully in 1941 (possibly an important point given the disturbance to the habitat). If Bick’s birds were the ones from John’s Bayou, it seems the male disappeared sometime between mid-August and December. Given the consistent presence of this family group in the vicinity for nearly a decade, there’s perhaps a hint of wishful thinking in Tanner’s suggestion that the male “might have moved away” due to the logging.

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The next interesting tidbits come from a 1938 interim report that Tanner sent to the Audubon Society, under the terms of his fellowship (the document below and accompanying map). The report includes a reference to a non-breeding pair in the Mack’s Bayou area. This pair does not show up in Tanner’s published counts, either in the monograph or in his dissertation. It seems possible that Tanner concluded the pair that was seen around Mack’s Bayou and the pair with two young that Kuhn found later were one and the same, erring on the side of caution in his final population estimates.

What stands out in both of these documents is the difficulty Tanner and Kuhn faced when trying to find ivorybills other than the John’s Bayou family. This is a topic I’ve touched on in several other posts because of the common belief, fostered by Tanner in later years and advanced by many 21st-century “skeptics”, that ivorybills should be easy to find.

During his brief, two week visit in 1941, Tanner couldn’t get to Greenlea Bend at all and didn’t find the Mack’s Bayou bird, although he found evidence that it was still there. The 1938 report illustrates how hard it was to find ivorybills even more explicitly. Kuhn and Tanner were unable to locate a pair that had been seen by others in a fairly circumscribed area, although it’s possible that Kuhn happened on this pair and the young of the year on June 15th.

Beyond that, it took Tanner and Kuhn “two or three weeks” to find an ivorybill in an area where there was “an abundance of feeding sign”, and Kuhn only found the bird in question by following it to the feeding sign from a known roost. It seems that, while ivorybills may sometimes have been “noisy and conspicuous”, they were for the most part quite the opposite.

Materials are courtesy of the Division of Rare and Manuscript Collections, Cornell University Library.

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Two More Rare Ivory-billed Woodpecker Images

These two photographs, taken by Tanner in 1938 and published in his dissertation, have not been otherwise widely disseminated or (to the best of my knowledge) reprinted elsewhere. Each is interesting in its own right, and not just because they add to the small body of indisputable ivorybill imagery; the first shows the behavior of a near-fledgling (Sonny Boy) in the nest and the second for the position of the male’s crest, which is more recurved than in most or all other stills. Another series of rare images is here. Images are Courtesy of the Division of Rare and Manuscript Collections, Cornell University Library. Screen Shot 2016-05-03 at 1.39.32 PMScreen Shot 2016-05-03 at 1.40.39 PM