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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


Bits and Pieces Part 4: Rethinking Range and “Suitable Habitat”

Part 1.

Part 2.

Part 3.

Bottom line upfront: In pre-contact and early colonial times and into the 19th century, Ivory-billed Woodpeckers inhabited a more varied and expansive range than most people realize. The range probably reached from the southern tip of Florida to central Ohio, with the 40th parallel as the approximate northern limit, westward to St. Louis and perhaps along the Missouri River. As discussed in the previous post, the western limit of the range appears to have been somewhere around the 96 or 97th Meridian, in the southwest, and probably somewhat farther east at the northwestern edge, if unproven historic reports from the Kansas City area are valid. Outside of coastal areas, distribution appears to have followed riparian corridors to its outer limits, and there are no records from elevations of over ~1000′.

A couple of maps may be useful for additional information about forest, bioregion, and habitat types and may help with visualization along with my map of records from unexpected habitats.

This is a new avenue of exploration for me, and I’m not personally familiar with many of the areas involved. I need to do additional research on areas within Tanner’s range map, along the coasts and in Florida, to be sure my characterizations are accurate. I’m leaving some of these locations on the master map for now (but removing them from the graphic below which includes extralimital and edge of range records). The master map is thus subject to change, so view it with the caveat that the notations may be incomplete or inaccurate. This post will address locations that are outside the confines of Tanner’s 1942 range map, although he accepted some of these records in 1989.

 

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As in the previous post, my analysis relies on records accompanied by reported physical evidence (even if that evidence has been lost) and to Native American sites where remains found are deemed unlikely to have been trade items. I relied on the US Fish and Wildlife Service’s Recovery Plan, Appendix E, Tanner, Jackson, and a few additional sources.

Before undertaking a whirlwind tour of the locations involved, I thought I should return to the mythology discussed in the previous post. I chose my words poorly in describing that mythology: “To a large extent these beliefs treat the Singer Tract as a model – a vast tract of “virgin” bottomland forest dominated by oaks and sweetgums, with abundant, moss-draped cypress for atmosphere (although ivorybills seem to have avoided cypress in the Tract).”

In fairness to Tanner, he didn’t characterize cypress as being abundant in the Tract. (It was not.) And his overall view was that cypress-tupelo swamps were not good ivorybill habitat. Audubon, with his romantic, indeed gothic, language is the father of the cypress myth.

I wish, kind reader, it were in my power to present to your mind’s eye the favourite resort of the Ivory-billed Woodpecker. Would that I could describe the extent of those deep morasses, overshadowed by millions of gigantic dark cypresses, spreading their sturdy moss-covered branches, as if to admonish intruding man to pause and reflect on the many difficulties which he must encounter, should he persist in venturing farther into their almost inaccessible recesses, extending for miles before him, where he should be interrupted by huge projecting branches, here and there the massy trunk of a fallen and decaying tree, and thousands of creeping and twining plants of numberless species! Would that I could represent to you the dangerous nature of the ground, its oozing, spongy, and miry disposition, although covered with a beautiful but treacherous carpeting, composed of the richest mosses, flags, and water-lilies, no sooner receiving the pressure of the foot than it yields and endangers the very life of the adventurer, whilst here and there, as he approaches an opening, that proves merely a lake of black muddy water, his ear is assailed by the dismal croaking of innumerable frogs, the hissing of serpents, or the bellowing of alligators! Would that I could give you an idea of the sultry pestiferous atmosphere that nearly suffocates the intruder during the meridian heat of our dogdays, in those gloomy and horrible swamps! But the attempt to picture these scenes would be vain. Nothing short of ocular demonstration can impress any adequate idea of them. 

Hasbrouck (1891) perpetuated the emphasis on cypress and very low-lying locations:

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Hasbrouck’s explanation of the Missouri extralimital records is odd. The locations given are well outside bald cypress range.

That aside, the myth discussed in the previous post is a composite. The emphasis on cypress originates with Audubon and Hasbrouck, and the emphasis on large tracts, old growth, oaks, sweetgums, and tree size is largely drawn from Tanner.

Here are the extralimital records:

Reedy River, South Carolina: Nest with eggs reportedly collected in 1896 and later lost. The location is in the Piedmont, south of Greenville, at an elevation of approximately 900′. The Reedy flows into the Salad, which flows into the Congaree. This report is listed in the Recovery Plan because it was accepted by Sprunt as “definitive” but is considered highly questionable.

Etowah Mounds, Georgia: Pre-contact site, elevation approximately 700′. Presumably not trade goods “but requires further discussion” per the Recovery Plan. The Etowah River is at the northern end of the Alabama River watershed.

Between Martinsburg, West Virginia and Winchester, Virginia: Specimen reportedly collected by Wilson ca. 1810. Elevation at Winchester is 725′ and at Martinsburg is 453′. This would appear to be in the Potomac watershed.

Moundsville, West Virginia: Two lower mandibles found in a pre-contact (early Common Era, 0-200) midden. Potentially trade goods. Elevation 696′. The location is on the Ohio River.

Philo, Ohio: Near the Muskingum River. Tarsometatarsus found in pre-contact midden, dates from ca. 1100-1500. Elevation 735′.

Sciotto County, Ohio: Same as above. Elevation of the site is 1050′, but the nearby Sciotto River is lower. The site is about 10 miles from the Ohio, and the elevation at the confluence is 533′.

Ross County, Ohio: Same as above. Also on the Sciotto River but farther upstream. Elevation 863′

Near Troy, Ohio: Near the Miami River, March 1804 sight record by Gerard Hopkins, a Quaker envoy to the Miami and Pottwatomi. The report includes a description, “. . . resembling the red headed woodcock of Maryland, except that its head is black and its bill ivory. ” (Leese 2001). Omitted from the map because it doesn’t involve a specimen, but included here because it adds weight to the archaeological records.

Franklin County, Indiana: Report of a specimen, 1869, now lost. Elevation at least 490′. Probably along the Whitewater River, an Ohio tributary. There are a number of early reports from Indiana, but no other reported specimens and no archaeological records. In light of Audubon’s collection at Henderson, KY (just across the Ohio River) as well as the Ohio records, it seems likely that ivorybills were present in parts of Indiana into the 19th century.

Henderson, Kentucky: Female specimen collected by Audubon in July 1810 and used as a model for his first painting of the species. Elevation 400′. This record does not appear in the Recovery Plan or Jackson, and it seems to have been overlooked by researchers. Audubon’s own notation describes the location as “Red Banks”, on the Ohio River at the northernmost limit of the cypress-tupelo association, well upstream from the confluence with the Mississippi. Article by R. Haven Wiley in Kentucky Warbler, May 1970.

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Stanford, Kentucky: Pair reported, with one specimen collected by a Colonel Fleming, 1790. Record accepted by Tanner in 1989. Elevation 942′. The Dix River, which flows into the Kentucky and thence the Ohio, is nearby.

Cahokia Mounds, Illinois: East of the confluence of the Mississippi and the Missouri, 1500s or earlier, tarsometatarsus. Elevation 490′.

Forest Park, Missouri or Vicinity: West of the confluence of  the Mississippi and Missouri. Specimen collected 1896 and in the collection of the Colorado Museum of Natural History. Elevation approximately 500′.

I find it interesting that Ohio is the state with the most pre-contact records involving likely food items – 3 out of a total of 4-6.

With regard to Missouri and the Missouri River watershed, Hasbrouck accepted reports from Fayette and Kansas City, and given the overall picture, this does not seem implausible. In addition, there were persistent reports from the vicinity of Lake of the Ozarks, in the Missouri River watershed, until the end of the 1940s; Tanner received information about Missouri reports from local Audubon society officers but apparently disregarded it. There’s no way to assess the validity of these old, anecdotal claims and no evidence to support them, but given this perspective on the historic range, they may be somewhat less far-fetched than it seems at first glance.

I’m heading for Louisiana soon. More after I return – a trip report and probably two additional installments.