Advertisements

Recent Trail Camera Results Part 2: Squirrel(s) on a Sweet Gum Stub

Summary

I suggest reading Part 1 for background and context, if you haven’t already.

The target of this deployment (5/3-6/3/2018) was the sweet gum stub discussed here. The tree was killed when its top was blown off in spring 2015. A patch of recent scaling was found this season. I suspect the initial scaling is woodpecker work, but squirrel is also possible. The extent is modest in terms of what I hypothesize is diagnostic for Ivory-billed Woodpecker:

A particular and distinctive looking type of extensive scaling (large contiguous areas with bark removed) with associated insect tunnels on bitternut and pignut hickory boles – live trees, snags, and stubs – may be diagnostic for ivorybill. For recent work, the presence of large bark chips at the base of such trees is a related potential diagnostic.

Insect tunnels are present on this stub. Species is/are unknown, and tunnels are small compared to those found in the hickories.

In contrast to the hickory discussed in the previous post, there were no woodpecker captures over the course of this deployment and squirrels were very active on the scaled area, appearing on May 4, 5, 8, 10, 12, 13, 15, 17, and 22. There were multiple visits on some days, and the total time spent on the scaled area was significant, upwards of an hour, with at least one visit lasting nearly 25 minutes. It was surprising that squirrel activity ended on the scaled area ended on May 22nd, and there was none over the next 11 days.

Over the course of this deployment, squirrels removed a modest quantity of bark, apparently in strips, from part of the scaled area. They did this inefficiently – with some difficulty and with the grain. The bark, already softer and weaker than hickory, has weakened in death and is at best moderately tight (relatively easy to peel off by hand). Captures from the first and last full days (note the Hooded Warbler on the branch to the left) of the deployment reveal how little bark was removed, all or almost all from the right side of the scaled area. (Click on the images to enlarge them.)

 

 

This suggests that squirrels are unlikely candidates for removing bark from hickory boles in quantity, leaving large chips behind, or initiating extensive scaling on hickories. In my view, it’s probably impossible for them to do so. The results for Pileated Woodpecker from the hickory deployment and squirrel from this one support my hypothesis that Ivory-billed Woodpeckers are the source of the initial hickory scaling. But more data are needed.

Background

Before turning to the trail cam captures and accompanying images of the scaled surfaces, I’ll provide some background information on the impetus for this post and on squirrel behavior.

An email discussion of squirrels and bark scaling was ongoing prior to my starting to review the images from this deployment. Wylie Barrow suggested an alternative explanation: that squirrels might be the source of much of the scaling (including the work on hickories) that’s taking place in the search area. He pointed out that  . . . “Squirrels have removed bark from 1/4 to 1/2 of the trunk and several large branches from large oaks in my yard… and they work with great speed. They often leave large bark chips on the ground beneath the trees. Trees are living and bark is tight and fairly thick.” (W. Barrow, pers. comm.)

At first, I took some umbrage at this suggestion, thinking that I had thoroughly examined and considered what squirrels might be doing on the hardwoods in our search area and what the upper limits of their capacities might be. While my basic views on this are unchanged, and the trail cam images tend to support those views, I’m grateful to Wylie for keeping me on my toes.

It’s certainly true that in the past I have failed to consider squirrels and the role they might play in bark scaling, and this has led me down some blind alleys, as was discussed in a series of posts in early 2016. I have also been too confident in those conclusions, even though I think this material supports them. Wylie’s suggestion led me to conduct additional online research on squirrels (and he provided additional references).

I had a number of off-the-cuff theoretical and observation-based objections to Wylie’s suggestion.

One evolutionary objection is reflected in a comment I made early in our exchange: “the predator in question would have to have evolved to take advantage of this very narrow window of opportunity when the insects are near the surface . . .” I thought and still think this points toward a woodpecker as the source, and toward a Campephilus woodpecker in particular, since this foraging strategy is characteristic of the genus.

The hickory scaling is associated with sapwood dwelling Cerambycid infestation, and signs of woodpecker activity (targeted digging around exit tunnels) are present in all cases. The homepage tree was very recently scaled when found, and woodpecker evidence was present. Wylie replied that squirrels are opportunistic and might be feeding on larvae; he went on to suggest that woodpeckers following the squirrels and doing targeted digs around the exit tunnels was a possibility.

In one paper on a tropical species of squirrel, it was observed that they prefer palm nuts infested with beetle larvae. The authors also note that squirrels have a strong preference for obtaining food in the most efficient manner, and that Eastern gray and fox squirrels will choose nuts lacking an endocarp (the hard inner shell) over those that are harder to open. When confronted with an endocarp, the tropical squirrels would attack it at its weakest and thinnest point, as do Eastern gray and fox squirrels :

Two of these pores have dead ends (with 1-mm depth), and the third is the germinal pore, which is deeper but is closed by a soft and easily penetrable tissue, located on the side opposite the fruit’s internal gibbosity. The internal gibbosity is a projection of the endocarp that inhibits the squirrel’s access to the endosperm when the fruit is opened from the side containing the dead-end pores. The squirrel must determine the position of the internal gibbosity to avoid it and thus save energy and time in obtaining the endosperm. These rodents are known to identify the side without the internal gibbosity even before beginning to open the fruit, with >90 percent success (Bordignon et al. 1996, Mendes & Candido-Jr 2014). However, how the squirrel identifies the side without the internal gibbosity remains unknown. As the gibbosity is always on the side opposite the germinal pore (Bordignon et al. 1996), this pore is an important access point that the squirrel can use to open the fruit efficiently. It is believed that the squirrel manipulates the fruit by pressing the three pores with its upper incisors, using the pore without a dead end for support so that the lower incisors can open the endocarp (Bordignon et al. 1996).

Efficiency is one of the main factors that determine the foraging strategy of Sciuridae. A laboratory study conducted with the squirrels S. carolinensis and S. niger found that individuals preferred various species of nuts with low energetic value that lacked an endocarp or shell over high energy nuts with an endocarp (Smith & Follmer 1972). These results suggest that there is a high cost in energy expenditure for processing seeds with endocarps for these species.

(Alves et al. “Queen palm fruit selection and foraging techniques of squirrels in the Atlantic Forest,” Biotropica 50(2): 274–281 2018). Efficiency is an important consideration in this context, especially with respect to hickories.

The reasons squirrels strip bark are poorly understood. Pine (or red) squirrels attack a number of tree species, “[d]uring winter, spring, and early summer, bark stripping and tree girdling for consumption of phloem and cambial tissues is common (Hosley, 1928; Linzey and Linzey, 1971; Pike, 1934). Pine squirrels also eat the bark of rust galls (Salt and Roth, 1980) as well as sap from sugar maple trees (Acer saccharum) in the northeast (Hamilton, 1939; Hatt, 1929; Heinrich, 1992; Kilham, 1958; Klugh, 1927; Layne, 1954) and yellow birch (Betula alleghaniensis) in the Great Smoky Mountains (Linzey and Linzey, 1971). Widespread, systematic sugar tapping by pine squirrels occurs in New England (Heinrich, 1992).” (Steele, M. A. 1998. “Pine squirrel (Tamiasciurus hudsonicus),” Mammalian Species 586:1–9).

Red squirrels have also been observed feeding on spruce bark beetles. (Pretzlaw, et al. “Red Squirrels (Tamiascurius hudsonicus) Feeding on Spruce Bark Beetles (Dendroctonus Ruffipennis): Energetic and Ecological Implications”, Journal of Mammalogy, 87(5):909–914, 2006). This was a novel observation at the time, and the behavior appears to have been a sudden and opportunistic response to a climate change-related bark beetle outbreak that lowered cone production. Spruce bark is soft, flaky, and fairly loosely adhering, and the bark beetles spend approximately a year, the entirety of their larval life cycle, in the phloem and hence are a readily available food source for a prolonged period. Moreover, “[f]oraging for larval spruce bark beetles by red squirrels is an obvious and stereotyped behavior; squirrels situate themselves on the trunk of the tree near ground level and peel off the bark to reveal and ingest larvae.”

There seems to be less agreement as to why Eastern gray and fox squirrels strip bark. It has been suggested that a calcium deficiency might be primary driver. C.P. Nichols et al., “A novel causal mechanism for grey squirrel bark stripping: The Calcium Hypothesis,” Forest Ecology and Management 367 (2016) 12–20. Bark stripping by Eastern gray and fox squirrels seems to be more prevalent in areas where the species have been introduced, “[b]ark-stripping behaviour, reported so often in Europe (Shuttleworth et al. 2015), is extremely rare in their native range (Kenward 1989).” (Koprowski et al. “Gray not grey: The ecology of Sciurus carolinensis in their native range in North America”, posted on Researchgate.com, 2016).

While “extremely rare” is an overstatement, it does appear that bark stripping occurs more frequently in areas where gray and fox squirrels have been introduced. It is a major problem in the U.K and Europe but mostly an annoyance in the United States. It seems reasonable to infer that it is more common in suburban and residential areas than in mature bottomland hardwood forests, though Wylie points out that the discrepancy in the reporting may be due to demographic factors and that squirrel behavior in bottomland hardwood forests has been poorly studied.

Gray and fox squirrel bark stripping seems to occur most frequently on branches, and I found no images in which insect infestation of the scaled areas was apparent. In addition, the examples of extensive squirrel scaling found online in no way resemble what we’re finding on hickories. Thus far, we have found only two references to squirrels stripping bark from trees in the genus Carya, one from pecans in Georgia and one from limbs in West Texas pecan orchards, where fox squirrels have been introduced. It’s not clear what parts of the trees were involved in Georgia and whether this report also came from an orchard, but regardless, pecan bark is flaky and not criss-crossed, making it easier to scale.

While neither Wylie nor I conducted an exhaustive literature review, we found no records of gray or fox squirrels scaling bark from any bitternut or pignut hickories (Carya cordiformis and Carya glabra), be it on limbs or boles, in several Google searches. Given the extensive range of these species – most of the Eastern United States and into Canada – and the association between squirrels and oak-hickory habitats, if squirrel scaling of hickories occurred with any regularity within the natural ranges, one would expect references to be abundant in both the popular and scientific literature.

As mentioned in the previous post and implied above, I suspect that the criss-cross pattern that characterizes pignut and bitternut hickory bark is one factor that deters squirrels from removing it and may prevent them from removing it in large pieces. This relates more generally to the question of efficiency. The characteristics of hickory bark make it extremely difficult for any creature to remove. In addition to the pattern of the grain, it is literally the hardest, strongest, thickest bark in the forest. On mature boles it can be 3/4″ thick (compared to around 1/16″ for a hickory endocarp). It is tight (though less so when sap is flowing), and it retains these characteristics long after death. Bitternut hickory bark does not flake, and pignut does so infrequently and superficially.

Thus, both species are exceedingly poor candidates for stripping by squirrels, especially when sweet gums and an array of other much easier targets are available. In contrast to the hickories, the target tree in this deployment was a sweet gum, three years dead, with thinner, considerably softer, loosening bark

As I see it, all of this militates against squirrels as the original source of the hickory scaling. While this is inferential and we have yet to document whatever initiates the scaling, the data obtained thus far support the inference. Only recently have we been able to deploy enough trail cameras for a meaningful and sustained effort. Nevertheless, we have had many hours of captures since 2009, in both search areas. To my knowledge, the only prior unambiguous capture of squirrel scaling is the one from 2015; it involved a downed, immature sweet gum with thin bark, which was easy for squirrels to scale. A second clip may show a squirrel removing a very modest quantity of thin bark from a sweet gum limb that was already being scaled by Pileated Woodpeckers (second video clip at end of post), and Wylie observed a squirrel scaling a sweet gum branch (on a roadside just outside the main search area) in December 2015.

I no longer think scaling on sweet gum limbs (so heavily emphasized in Tanner) is a strong indicator of ivorybill presence, at least not on its own, although what we’ve found in the search area seems to be unusual. Abundance, lack of correlation with low mast years, bark chips, absence of incisor marks, and indications of woodpecker activity, especially targeted digging, may all be suggestive. Sweet gums, which are very attractive to beavers, are likely one of the most desirable targets for squirrels as well, for reasons of flavor and efficiency.

But we have documented no squirrel scaling on hickories, live or dead, on limbs or on boles, partially scaled or with bark intact.

I think the results from this deployment shed considerable light on the issue of squirrels and bark scaling, especially what they do (or can do?) on a mature bole with thick bark. So let’s go to the videotape, as a New York sportscaster used to yell.

Squirrels on a Sweet Gum Bole

As with the previous post, our Plotwatcher Pro trail cam is programmed to capture one image every twenty seconds, and these time-lapse sequences have been converted into QuickTime movie format. If you want to get a clearer sense of how the squirrels are behaving, you can step through the films frame-by-frame. If you elect to watch just one of the clips, the one from May 8 that starts at Frame 1500 (the squirrel spent 24 minutes on the scaled surface) or the one from May 12 that starts at Frame 1574 might be your best bets. Discussion and close-ups of the scaled surface follows the bonus imagery.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

While we had no woodpecker detections on the stub and bird captures were few, we did catch some hogs (piglets?) and a beaver. Also captured but not shown were a Northern Cardinal and an Eastern Phoebe.

 

 

Discussion and Details

As best I can tell, the only expansion of the scaled area involved a narrow strip at the upper right, probably no more than 12″ x 2″, and a little widening at the very top, although this was an area where the squirrels spent a considerable amount of time.

Let’s look at some details from that scaled area.

P1170436

Upper Part of Scaled Surface Showing New Work

 

 

 

 

 

 

 

 

 

 

 

 

 

 

While there appears to have been some woodpecker excavation at the middle left of the larger scaled patch, there’s no readily apparent sign that woodpeckers have been after the insects that are feeding in the sapwood. Nor is there any strong indication that squirrels were feeding on insects over the course of this deployment, though it’s possible they took advantage of snails and beetles, like the ones in the photo, or slugs, which I also saw on the scaled patch.

The edges of the bark shown in the close-ups, especially the one at the top, show signs of having been gnawed, although this is subtle, and sometimes impractical as an identifier, since such close examination is not always possible in the field. I presume that the abundant squiggly abrasions to the surface of the underlying wood are incisor marks, something we have not observed with other scaling we’ve found.

With regard to what was left behind, the first three photos show what I found at the base of the snag when I discovered the scaling on May 1, 2018.

 

The large, though narrow, strip of bark was the biggest one I found at the base and is one of the main reasons I suspect that woodpeckers initiated the scaling with squirrels following, although I would not rule squirrel out completely. In any event, the bark was so soft and weak that it broke in my hand when I picked it up on June 11. The other thin strips are more consistent with what I’d expect for squirrel, and the tiny orange pieces of cambium are a giveaway.

The situation had changed little during this most recent trip. The picture with my boot shows the larger pieces of bark I found at the base, including the one shown above after it broke. They may be consistent with woodpecker (possibly including Red-bellied or Hairy), but I suspect that both squirrels and woodpeckers were involved in the bark removal.

 

Edited to add: For any extensive squirrel work on mature boles, especially hickories, I would expect to find many small pieces of bark on the ground, similar to those shown above, as in this dramatic example.

My main objective in targeting this stub was to observe it over time, more for what might happen as the decay advanced and whether it might become a target for ivorybills; it’s the type of “stump” that Pearson described as being favored by ivorybills after his visit to the Singer Tract in 1932, though Pearson’s “stump” (scroll down in the linked article) was much longer dead.  The bark scaling, while interesting, was in the “could have been anything” category. Getting this data on squirrels was a pleasant surprise, one that I should have anticipated based on the small bits of cambium on the ground. My bias came into play, as I ascribed them to a smaller woodpecker. Between Wylie and the trail cam results, I’ve learned a lesson. In terms of the bigger picture, however, the results so far suggest that squirrels are not the source of the putative Ivory-billed Woodpecker scaling on hickories.

Advertisements

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.

Screen Shot 2017-09-16 at 7.59.35 AM

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 verifiable 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).

 


Not So ‘Virgin’ Forest: The Singer Tract Myth Debunked

Update: This post includes hard data about the extent of old growth in the Singer Tract (scroll down past all photographs) and in ivorybill home ranges. The general points made below remain valid, although some of the wording is perhaps too strong; Tanner overestimated the amount of old growth in the Tract ( at “over 80%” v. 72% in fact), and the Mack’s Bayou home range was predominantly second growth.

This post is a companion to the previous one and to others discussing habitat conditions in the Singer Tract. Those posts reference Richard Pough’s 1944 report to the Audubon Society. Pough, whose study was never published, noted that much of the Singer Tract had actually been under cultivation prior to the Civil War. But it’s worth taking a closer look at just how much.

Tanner characterized the Singer Tract as “the largest tract of virgin timber in the Mississippi Delta,” contending that it contained “120 square miles of virgin forest in 1934”. He also wrote that the largest plantation “had about 3000 acres under cultivation,” while suggesting that “some of the early settlers along the Tensas River cleared land along the river banks for cotton fields.” Thus, the myth of the Singer Tract as virgin forest was born.

It’s not clear where Tanner got his information, but some of his characterizations are not supported by the historical record; the language about “early settlers” almost seems disingenuous when one looks at the history of Madison Parish. (Rootsweb has many pages devoted to this subject, and I’ve drawn heavily on them for this analysis.) As should become evident, there was a great deal of human activity in and around the Singer Tract, especially prior to the Civil War. I will suggest that most, perhaps virtually all, of the arable land in the parish, had been cleared for agricultural purposes and that the Singer Tract was a mix of second growth and remnant old growth, most of which was in the lower-lying, wetter areas that Tanner deemed to be less suitable for ivorybills.

A 1937 Masters thesis in economics by Robert L. Moncrief, “The Economic Development of the Tallulah Territory”, provides a great deal of information about the parish and its history. In the post-Columbian era, the area was very sparsely settled until the 1830s. Madison Parish was established in 1839, and in 1840, steamboats began plying the Tensas River. A major population influx began in 1836, and the population kept growing until the Civil War, going from 5,142 in 1840 to 14,133 in 1860. The war led to a dramatic decline to a mere 8,600 in 1870. Over the next couple of decades, the numbers grew again to 14,135 in 1890. Changing economic conditions and the boll weevil outbreak caused another decline that was only reversed between 1920 and 1940, when the number of residents reached 14,826. By 2010, it had fallen to 12,093.

Cotton and the quality of the soil drove this influx. By 1850, there were 27 landowners in the parish who owned more than $20,000 (over $590,000 in 2015 dollars) worth of real estate. The largest holding was valued at $140,000 (well over $4,000,000 in today’s dollars).

According to Moncrief, “the newcomers cleared away the heavy forests and planted the new ground in the favored crop then, as now –– cotton. They cleared all the lands fronting water courses (which are the highest and most desirable lands for cultivation in this region) to form a continuous line of plantations along the streams.” Streams in this context refers not just to the Tensas but also to the smaller non-navigable bayous. Cotton raised along the smaller streams was brought down to the Tensas in flat-bottomed boats.

Moncrief’s thesis also includes figures for cotton and corn production in Madison Parish. Cotton production peaked at over 46,000 bales in 1858. (Pough was apparently incorrect in stating it was over 100,000 bales; he may have combined the total with that of an adjoining parish.) It had fallen to 1,830 by the end of the war. Production recovered between 1870 and 1875 and reached a postwar/pre-boll weevil peak of 25,981 bales in 1890, about the same level of production as in 1936. Corn production peaked at 618,620 bushels in 1859, falling dramatically after the war, peaking at 836,000 bushels in 1909, and then falling to 320,000 by 1936. My crude, back of the envelope estimate based on  yields of 5 bales per acre for cotton and 15 bushels per acre for corn, suggests that between a quarter and a third of the total acreage in the Parish was under commercial cultivation prior to the war.

While Moncrief’s paper evokes Tanner by describing the Singer Tract as 81,102 acres (126 square miles) of virgin timber, it also notes, “The tract includes several abandoned and grown up plantations, which after the Civil War, reverted to the state and were later sold to the present owners.” The ruins of one plantation house are still standing, deep within the Tensas National Wildlife Refuge.

While it was adjacent to and not strictly part of the Singer Tract, the story of the Frisby Plantation is illustrative. The plantation was established in the early 1850s with land acquisitions taking place over the next decade. Norman Frisby, the founder, was murdered by his nephew by marriage in an 1863 in a dispute over property. When Frisby’s widow was forced to sell the plantation in 1870, it totaled 19,479 acres, and its crops generated over $77,000 in revenue (the equivalent of $1.36 million in 2015). Tanner visited the site of the plantation and photographed one of its old fields. I haven’t been able to pinpoint the location of the old house; one 19th century survey survey seems to place it in Tensas Parish, near Fool’s River. Another account (from the history of the Sharkey Plantation discussed below) says it borders Disharoon (or Dishroom) Bend, much closer to the core of the Singer Tract. As shown on this overlay of 1875 land ownership on a modern map, the Frisby holdings included parcels adjacent to Mack’s Bayou and on Dishroom Bend.

The maps help flesh out the story. An earlier and incomplete parish-wide map of patentees shows that many parcels in the Singer Tract were purchased well before Frisby started acquiring land in the 1850s. Lands purchased in the 1840s include parcels along John’s and Mack’s Bayous, which makes sense since frontlands along streams were most desirable. This history of the Sharkey Plantation reveals that land sales began in the heart of Tanner’s search area during the 1840s. The author explains that the Sharkey plantation and others like it were more like communities, with a cluster of families (and presumably their slaves) living in close proximity, near a watercourse.  The 1875 map shows that much of the Singer Tract remained in private hands even after many parcels were abandoned during the Civil War.

Perhaps even more telling is this hand drawn map of Madison and Carroll Parishes from 1862. It shows the locations of towns, roads, ferry crossings, and plantations in the Singer Tract area. While it is incomplete and John’s Bayou is not shown, Sharkey Road is there, cutting in a southwesterly direction from the Richmond-Carthage road, crossing Alligator Bayou, and the Swearingen parcel. Another road crosses the heart of the Mack’s Bayou home range and the Tensas itself. The map delineates abandoned plantations and appears to show that, except for those abandoned areas, some cotton was being grown in every division of the Singer Tract. However limited the agricultural activity may have been in these sectors, the area was hardly a primeval wilderness; habitat had been fragmented; and old growth conditions were likely restricted for the most part to areas unsuitable for farming.

This passage from an 1885 article from the New Orleans Times-Picayune sheds some additional light on conditions in the area both before and after the Civil War. “But little has been said about Tensas River and Joe’s Bayou as, but little interest is there as compared with former years. Before the war there was a continuous planting interest all along those two streams but overflows and the war left them to grow up into weeds and bushes. In 1870 Mason, and later Loyd bought cattle from other parts of the country and carried them to those bayou places for pasturage, wherein a few years they made large sums of money. This was in the neighborhood of Quebec, which before the war was a flourishing little city, shipping 7090 bales of cotton. It was at the junction of the Tensas River and the railroad. It is now a waste place and to pass there on the railroad you would never know that a town had been there.” (In The Race to Save the Lord God Bird, p.76 Hoose plays into the virgin forest myth by claiming that railroads “finally reached the Tensas River sometime around 1900.”) Quebec was just a few miles outside the tract, near Bayou Despair, where Tanner listed a pair from 1934-1936.

The Rootsweb pages provide a couple of additional and important pieces of information.

Theodore Roosevelt visited Madison Parish in 1907.  Roosevelt’s descriptions provide added detail about conditions in and around the Singer Tract several decades after the Civil War. According to Roosevelt:

“Beyond the end of cultivation towers the great forest. Wherever the water stands in pools, and by the edges of the lakes and bayous, the giant cypress loom aloft, rivalled in size by some of the red gums and white oaks. In stature, in towering majesty, they are unsurpassed by any trees of our eastern forests; lordlier kings of the green-leaved world are not to be found until we reach the sequoias and redwoods of the Sierras. Among them grow many other trees–hackberry, thorn, honeylocust, tupelo, pecan, and ash. In the cypress sloughs the singular knees of the trees stand two or three feet above the black ooze. Palmettos grow thickly in places. The canebrakes stretch along the slight rises of ground, often extending for miles, forming one of the most striking and interesting features of the country. They choke out other growths, the feathery, graceful canes standing in ranks, tall, slender, serried, each but a few inches from his brother, and springing to a height of fifteen or twenty feet. They look like bamboos; they are well-nigh impenetrable to a man on horseback; even on foot they make difficult walking unless free use is made of the heavy bush-knife. It is impossible to see through them for more than fifteen or twenty paces, and often for not half that distance. Bears make their lairs in them, and they are the refuge for hunted things. Outside of them, in the swamp, bushes of many kinds grow thick among the tall trees, and vines and creepers climb the trunks and hang in trailing festoons from the branches. Here, likewise, the bush-knife is in constant play, as the skilled horsemen thread their way, often at a gallop, in and out among the great tree trunks, and through the dense, tangled, thorny undergrowth.”

The most salient point here is that Roosevelt’s “great forest” applied to low-lying areas in which there was standing water (something that Hoose glosses over). Roosevelt also saw three Ivory-billed Woodpeckers:

“The most notable birds and those which most interested me were the great ivory-billed woodpeckers. Of these I saw three, all of them in groves of giant cypress; their brilliant white bills contrasted finely with the black of their general plumage. They were noisy but wary, and they seemed to me to set off the wildness of the swamp as much as any of the beasts of the chase.”

 

A photograph from the hunt is here. Tanner seems to have been unaware of the Roosevelt encounter. Roosevelt’s visit came just 17 years into cotton farming’s second decline and 52 years after the end of the Civil War. Habitat conditions are likely to have been poorer in general than when Tanner was there 3 decades later. The relative ease with which Roosevelt saw three ivorybills (despite their wariness) suggests they were not uncommon in 1907 and calls Tanner’s assumptions (pp. 48-50) about fire, tree death, and population influxes between 1911 and 1930 into question.

There’s another gem in the Rootsweb pages. It’s not directly on topic, but it relates to Tanner’s later dogmatism. In arguing for extinction and dismissing post-Singer Tract reports, many of which involved birds being flushed from tree stumps or other locations near the ground, Tanner characterized this behavior as being characteristic of pileateds not ivorybills.

Rootsweb has a newspaper account of  T. Gilbert Pearson‘s  visit to the Singer Tract in 1932. Pearson (who was President of the Audubon Society at the time) was the first ornithologist to confirm the presence of ivorybills in the Tract. He saw, “The birds . . . feeding on stumps of rotting trees, the tops of which had been broken off. A favorite place for feeding is also on dead limbs at or near the tops of the very tall sweet gum trees found abundantly in this region.”

The evidence that relates directly to Tanner’s study area and its immediate environs suggests that claims about “virgin forest” and IBWO dependency on old-growth are based on flawed premises. The Singer Tract was no doubt a remarkable place, a huge area of contiguous and relatively undisturbed forest, but it’s clear that much of it was not old growth or “virgin”.

It’s more useful to think about what the Singer Tract is likely to have offered Ivory-billed Woodpeckers – some measure of seclusion, enough big trees for roosting and nesting, and an abundance of standing and fallen deadwood. The myth that the Ivory-billed Woodpecker required vast tracts of “virgin” forest may be emotionally compelling, but it’s not based on evidence; it’s time to put it to rest.

I’m looking forward to spending a week in the field starting just after Christmas.