Bits and Pieces Part 6: Rethinking Range and Habitat – Implications

If you’ve been following this series (Part 1, Part 2, Part 3, Part 4, Part 5) you know it has focused primarily on preconceptions about ivorybill range and habitat types and how the actual record paints a very different picture from what many of us think we know about the Ivory-billed Woodpecker. As I noted in the most recent installment, if our knowledge of the Ivory-billed Woodpecker were based on the archaeological record alone, we’d think of it as an upland species. Further, we might very well assume that it ranged from the hills of Georgia, to the Alleghenies in Virginia, to central Ohio and west-central Illinois.*

While it may border on heretical to say so, I think there’s a plausible argument that the ivorybill’s range prior to around 1800 extended as far north as the mid-Atlantic states (New Jersey and Pennsylvania on the Eastern Seaboard) and as far north as central Ohio west of the Appalachians. I’m inclined to think this is likely based on a number of accounts including: Peter Kalm (a student of Linnaeus who reported the species was present in New Jersey and Pennsylvania in the 18th-century), Jefferson (1780s) and Nuttall (1840s) who included Virginia in the range, and Gerard Hopkins a Quaker from Maryland traveling to Indiana to meet with the Miami and Potowatami Nations. Hopkins described a female ivorybill at Piqua, Ohio (north of Dayton, elevation 873′) in 1804 (Leese, 2010.)

In addition, there’s the specimen that Wilson reportedly collected near Winchester, Virginia ca. 1810 (Jackson) and the central Kentucky specimen reportedly collected in the 1780s (Jackson, accepted by Tanner in 1989). As I see it, the tendency to treat these records as suspect is based, at least in part, on post-Civil War or post-Audubon “knowledge” about the ivorybill and its habitat, rather than anything intrinsically implausible about the claims themselves.

At minimum, one of the Ohio archaeological finds dates to the 15th or 16th century, so there’s strong reason to think that the ivorybill’s range extended that far north at the time of contact. North American Native populations began to decline after Columbus’s arrival, and De Soto’s expedition, 1539-1542,  led to the collapse of the Mississippian culture. (De Soto also introduced the hogs that plague the southern forests to this day.) As a consequence, countless acres of formerly agricultural lands throughout the eastern United States were reforested and remained so into the 18th and 19th centuries. There’s little reason to think that the ivorybill’s range would have contracted at a time when the total acreage of potential habitat was increasing.

I’m reminded that tree girdling may have been an important factor. The only counterargument to the foregoing suggestion about the increase in total acreage after De Soto is that Native American agricultural activity declined drastically during that period, so that while habitat acreage increased, habitat quality may not have. Tree girdling and intentional burning likely played an important role in creating good conditions for ivorybills and could conceivably have led to range expansion during the Mississippian period and again temporarily during the first couple of hundred years of European settlement.

Ivory-billed Woodpecker use of girdled trees was noted by several early observers – notably Audubon, Gosse, and Scott (in Florida, later). While researching this aspect, I came across an interesting account from 1840s Central Louisiana, apparently just south of Alexandria (the citizens of that city are described as “chiefly gamblers or cunning speculators, a nest of incarnate devils, who live by cheating the latest comers, and, whenever possible, each other.”) I’m not aware of this account having found its way into ivorybill literature:

Screen Shot 2018-01-17 at 10.01.03 AMScreen Shot 2018-01-17 at 10.01.19 AM

From Echoes from the Backwoods; or, Scenes of Transatlantic LifeCaptain R.G.A. Levinge (1849).

With this as background, I’d like to propose an alternative explanation (or more accurately an alternative group of explanations) for the ivorybil’s decline. If you think, as I do, that the ivorybill has persisted, this may help explain how the species survived and may even provide some hope for its future, even in this era of mass, anthropogenic extinction.

When it comes to the decline and possible extinction, there has been a tendency to look for one or two causes. The IUCN Species Account gives the following reasons:

Logging and clearance for agriculture are responsible for the dramatic decline in numbers and range. These factors are likely to threaten any remaining population. Hunting has also been implicated in the rapid population decline, and it has been proposed that this was the primary cause of its decline, with habitat destruction playing a secondary role, but this theory is contentious (Snyder 2007, Hill 2008, M. Lammertink in litt. 2012).

Tanner emphasized the importance of logging during the post-Civil War era, although several of his data points seem to suggest that ivorybills were disappearing prior to the most active logging dates. He also stated that the ivorybill’s disappearance “coincided at least roughly with a time of active or rapidly increasing logging.” Elsewhere in the monograph, he focused on food supply, and I suspect that this, rather than logging per se was a more important factor in the ivorybill’s decline.

That’s not to say logging was unimportant; it clearly played a major role. To expand briefly on the point Bill Pulliam raised: by the late 19th century, the more adaptable Pileated Woodpecker, had been extirpated in many parts of its range, and many expected it to ‘go the way of the ivorybill’. That didn’t happen, and PIWOs returned to or became more common in many areas (my own included) as farming gave way to suburban development and forested acreage increased as a result. I’d suggest that for the ivorybill, habitat degradation, rather than habitat loss, was what initiated the decline, with extensive logging and then hunting accelerating an already existing trend.

That is to say, a number of additional anthropogenic factors likely played a role in the ivorybill’s decline and dwindling range, especially outside of Florida, where hunting and collecting likely had much greater impacts than elsewhere. Hasbrouck, writing in the 1890s, contrasted the lack of collecting in Louisiana, Arkansas, Missouri, and Tennessee with what was transpiring in Florida at the time. And it’s important to remember that Florida, which retained ‘frontier’ characteristics far longer than other parts of the eastern United States, was ground zero for the killing and collecting of birds – for commercial and ostensibly ornithological purposes. Ivorybills appear to have been more common in Florida than elsewhere by the second half of the 19th century, but it also seems probable that they were far more heavily persecuted there than anywhere else.

I’m hypothesizing that the shrinking distribution was correlated with settlement patterns in the northeastern part of that range and that by the middle of the 19th-century, east of the Mississippi, it had dwindled to the now familiar outlines, such as those shown on the IUCN range map. Screen Shot 2017-12-22 at 3.42.31 PM

The situation west of the Mississippi is somewhat more ambiguous. A specimen was collected at Forest Park, Missouri (near Saint Louis) in 1886, and there are records from west of the map in Texas dating to the early 20th century. Nevertheless, the general trend toward a shrinking range, which was frequently described in the 19th century literature, is clear.

European settlement brought about numerous changes in the land even before wholesale clearing of forests began.

As mentioned briefly in the discussion of tree girdling, Native Americans used fire for agricultural and wildlife management purposes, something that was likely beneficial for ivorybills. As Native Americans were exterminated, pushed out of their original homelands, or confined to small reservations, and as European settlers tried to control or eliminate fires, a significant factor contributing to tree mortality was likely reduced, dramatically.

Fulton’s invention of a commercially viable steamboat in 1807 revolutionized commerce, drastically accelerating the clearing of log jams from many watersheds in eastern North America. It’s fair to say that “widespread removal of instream wood for steamboat routes, timber rafts, and flood control was equally significant in decreasing floodplain sedimentation and river complexity, and in causing a fundamental, extensive, and intensive change in forested river corridors throughout the United States.” (Wohl, 2014.) As with changes in fire regimes, this clearing of log jams likely led to a decline in the number of stressed and dying trees along the riparian corridors that seem to have been so important for the ivorybill.

Perhaps equally if not more important in my view is the extirpation of the beaver. It is almost impossible to overstate the role of the beaver in shaping ecosystems throughout North America, a subject that’s addressed in engaging detail in Frances Backhouse’s Once They Were Hats. Beavers help create conditions that are good for woodpeckers by stressing and killing trees, through foraging and by changing hydrology. I’ve never tried to quantify it, but many, perhaps most, medium to large sized sweet gums in our search area show signs of beaver damage, and many others have been killed or severely weakened by beaver-caused flooding.

While beavers are not native to peninsular Florida, the ivorybill’s dwindling range elsewhere roughly tracks their decline; with extirpation starting in the northeast, moving West, and then South. (Southern beaver pelts were less valuable.) By 1900, beavers had disappeared from most of the southeastern US, and in Tanner’s day, a very small population persisted in the Florida Parishes of eastern Louisiana. Reintroductions began in the 1950s, and beavers are now considered a pest animal in Louisiana. It’s worth pointing out that the introduced beaver population in Tierra del Fuego appears to be benefitting the native Magellanic Woodpecker (Soto et al. 2012).

The resurgence of the beaver throughout the southeastern US is almost certainly producing substantially improved habitat conditions in many places. While the old growth forests may be virtually gone, it’s not inconceivable that ivorybill food sources are considerably more abundant now than they were in Tanner’s day, and if the species survived, conditions may actually be more favorable than they were in the 1930s and ’40s. It’s also worth pointing out that the southeastern United States is one of the few places in the world where forest cover has increased substantially in the 21st century.

It should be clear to readers of this series that the Ivory-billed Woodpecker inhabited a larger range and was able to exist in more varied habitats than most publications on the species suggest. This has implications for searchers and for what is deemed to be suitable habitat. For example, the trail cam images from the old Project Coyote search area were obtained near the edge of a bean field, and the putative ivorybill roost holes were in willows (more on that in my next post). Since ivorybills in the western part of their range seem to have lived in willow and cottonwood dominated riparian corridors, fast growing, short-lived willows might have played an important role in the species’ survival in other areas too, although willow-dominated habitat would be dismissed as unsuitable under conventional standards of habitat appropriateness.

It seems to me that even a slightly higher degree of adaptability would increase both the chances of survival and the likelihood that surviving populations might be overlooked due to preconceptions about habitat “suitability” ; this was doubtless one of the factors that led officials to dismiss the landowner in our old search area. Now that beavers are again abundant in the southeast, habitat that might otherwise have been deemed “unsuitable” may now be able to support ivorybills, even if the forest itself is not very old. While I don’t envision a recovery along the lines of what’s happened to the Pileated since my youth (when seeing my first one was a thrill as much for its scarcity as its beauty), I think it’s possible that ivorybill numbers have been increasing gradually and modestly over the past few decades. There was, of course, fairly intensive searching from around 2000-2010 (though it’s mostly over now), but it may be that the more numerous sightings from this period and afterwards are due to more than just the increased effort.

*The remains found in Native American middens were unlikely to have been trade goods; ivorybill parts seem to have been a valuable commodity for ceremonial use west of the Mississippi but not east of it, and in several cases, the remains found were tarsometatarsi, which would be consistent with use as food:

There is strong physical evidence of  ritual value for woodpecker scalps and bills from the upper Midwest and Plains . . .  Remains of the Ivory-billed Woodpecker can be found in sacred bundles, on pipe stems, on amulets, and with burials among the Native Americans of the region. The evidence comes from the western Great Lakes and the Plains; no
evidence of a particular use of Ivory-billed Woodpeckers has yet been un-
covered from the eastern area of the Great Lakes (Ohio, Indiana, and Michigan).

(Leese, 2006.) Leese also points out (in several of his publications) that there’s no evidence that ivorybill parts other than scalps and bills had any trade value.

A number of these midden records were accepted by Tanner in his unpublished 1989 update.


Trip Report: December 27, 2017 – January 1, 2018 and Some New Year’s Appreciations

I returned to the main Project Coyote search area where I spent December 27-January 1. I was joined by two new team members – Erik Hendrickson, an excellent birder and retired National Park Service engineer who had an ivorybill sighting in Arkansas back in 2005, and Jay Tischendorf, a veterinarian with a long and adventure-filled background as a field biologist. Erik lives in Colorado, so he may not be able to visit often, but Jay is much closer. I hope that both of them will be able to return and bring their considerable skills to the effort.

Stephen Pagans, who has been with Project Coyote since 2012, was in the area for the duration. Steve is a retired forester, avid birder with a great ear, and an outstanding photographer. This portrait of a feral hog (more on hogs later), which I think is award-worthy, is just one example of his work.

003 Feral Hog,a

Feral Hog Photographed by Stephen Pagans

Tom Foti made it down from Arkansas for a day. Spending time in the woods with Tom, whose knowledge of bottomland forests is second to none, is always an education. On this trip, Tom pointed out that I’d been mistaken about the hickories in the search area. I believed that they were all bitternut hickories (Carya cordiformis), except for a very few shagbarks (Carya ovata), but it turns out that many, perhaps the majority, are in fact pignut hickories (Carya glabra). One of these, shown below, has a DBH of 42″ and may be a state champion. Tom also identified a nutmeg hickory (Carya myristicaeformis), an uncommon species that may not have been previously recorded in the parish.


Jay Tischendorf beside a potential champion pignut hickory

Nutmeg Hickory

Nutmeg Hickory Photo by Erik Hendrickson.

Having such great companions for the week caused me to look back at the past year, with its terrible low points – the losses of Frank and Bill Pulliam – and high points, particularly the March recordings, which I think are among the strongest evidence of ivorybill persistence obtained to date, and to appreciate my friends, collaborators, and outside advisors. Although I’ve been the public face of Project Coyote for years (Frank wanted it that way), this has always been a team effort, although the composition of the group has shifted over time. While it would be cumbersome to name everyone involved and some frequent advisers prefer to remain anonymous, there are several, in addition to those mentioned above, whom I’d like to acknowledge publicly.

On more than one occasion over the years, Bob Ford has lifted my spirits when they most needed lifting. When I talked to Bob shortly before Frank’s death, I was despondent. I knew Frank’s prognosis was not good and was having doubts about carrying on. Bob helped me see a way forward, reminding me that the search area is important, ivorybills or no ivorybills, and that I’d done meaningful work related to its ecology in general.

Matt Courtman, who had some involvement early on and had known Frank for several years, reached out shortly after Frank died, giving me much needed moral and intellectual support and breathing new life into Project Coyote. In one of those odd coincidences, Matt’s New York relatives knew and did business with my father decades ago.

Philip Vanbergen, the youngest among us, had the presence of mind to turn on his recording device on March 11 and capture a couple of calls, setting the stage for his and Matt’s return on the 15th when the much longer recordings were made. Phil has also been responsible for our trail cams since 2016. His energy, enthusiasm, and interest in the natural history of the area are invaluable.

Peggy Shrum’s ideas, background studying raptors in the Peruvian rainforest (a considerably more challenging environment), and familiarity with tropical Campephilus double knocks are great assets. Peggy has made the long trip from South Carolina to participate several times, and it’s always a pleasure to have her along.

Tommy Michot and Wylie Barrow from Lafayette have also been great sources of support. Though Tommy is a retired biologist with a Ph.D, I admire his youthful enthusiasm, open-mindedness, enjoyment of the woods, and his sense of humor. To top it off, he’s also an accomplished traditional Cajun musician from an illustrious musical family.  Wylie and Tommy have known each other for years, and while Wylie has seldom been able to make it into the field, his careful, scientific approach and probing questions help keep me on track. While I skipped it on this most recent trip, the lunches I have with Wylie and Tommy (and sometimes Phil) in Lafayette on the way home invariably help me absorb and evaluate whatever I’ve observed or experienced while searching.

Professor Fredrik Bryntesson has been a great online friend and supporter. He has shared details from his research into some arcane aspects of ivorybill history, some of which have found their way onto the blog. I hope we get to meet in person and that he will be able to visit our search area sometime soon.

Finally, Patricia Johnson, my wife – Patricia comes along from time to time, holds down the house when she stays at home. Her moral and morale support sustain me.

Though 2017 was difficult, I’m grateful to be surrounded by such great collaborators. I’m hoping for more highs and fewer lows in the year ahead . . . Without further ado, here’s the trip report. As with the previous one, I’ve opted not to do a day-by-day log. There’s not all that much to report.

The weather this trip ranged from cloudy, dreary, and damp to bitterly cold; there was little sunshine, except on January 1st, and avian activity was generally low throughout. Woodpeckers, except for Red-headeds, were mostly quieter and less active than usual. Nevertheless, on at least one day, we saw or heard all seven species (ivorybill excluded) that are found in the area at this time of year.

Birds may not have been very active, but the hogs certainly were. We saw upwards of 15-20 on a couple of days, and signs of their rooting were everywhere. Their numbers seem to have increased considerably since 2012, despite the presence of at least a few dedicated hunters in the area. We ran across these newborn hogs and assumed their mother had been shot. Their cute appearance belies their destructive potential should they survive. IMGP5639

We did not have any possible ivorybill encounters and found little recent bark scaling, except on two or three sweet gums,  some extensive work on a pine, and a small patch on a cypress. Some commentary below the images.

Phil solved the problem with the trail cams, and we now have three deployed on hickories – two that have lost their tops and one that is in obvious decline. We’ll deploy the fourth in the spring when it will be easier to locate unhealthy trees. Given what we’ve observed and the life cycle of the beetles involved, I think scaling on hickories is most likely to take place between mid to late spring and fall.

IMGP5580IMGP5583Fresh scaling on the bole and branches of a recently uprooted sweet gum. Some of the bark chips were large and consistent with what I would expect for Ivory-billed Woodpecker.


Extensive, recent scaling on medium and large sweet gum limbs.

058 Sweetgum Scaling

Recent scaling on large sweet gum limb. Photo by Stephen Pagans



Extensive scaling on a freshly dead pine top (needles still attached).



Scaling, targeted woodpecker dig, and insect galleries on a beaver-killed cypress.

With regard to the sweet gum scaling, it is far and away the most abundant form of this work we’ve found, and this has been true year after year. It is considerably more common in the Project Coyote search area than in other places I’ve visited or than in the Pascagoula, based on the Carlisles’ efforts there. It also matches the work described by Tanner as being typical of ivorybill, but as discussed in my post entitled Bark: An Exegesis, sweet gum bark is relatively easy to scale, making it more difficult to exclude Pileated Woodpecker. As an aside, I’m puzzled by the fact that we found a good deal of scaling on oaks in 2012-2013 and have seen virtually none since then.

While I’ve written previously that I think pine has no potential for being a diagnostic because it is easily scaled, the example above impressed me for its extensiveness and the fact that the presence of needles suggests the tree died very recently. Lighting conditions in the field were so poor that it was impossible to see that scattered patches of bark remained. This only became apparent when I brightened the photographs. Even so, the extensiveness so soon after death remains impressive.

I’ve included the beaver-killed cypress scaling here not because I think it’s likely ivorybill work; it could be, but the bark was loose, and the scaled area, while contiguous, covered only a modest percentage of the bole. What may be significant is the presence of insect work of a kind that is suggestive of suitable ivorybill prey. Tanner thought that cypress-tupelo swamps were poor habitats for the ivorybill, presumably because both are long-lived and relatively insect-resistant species and perhaps because he rarely ran across large scale deadenings of those species. The example shown here leads me to wonder about this assumption, particularly in places where beavers are present or other disturbances occur; fire, to which water tupelos are apparently vulnerable, for example. While Allen and Kellogg reported that Florida ivorybills nested in cypress and fed nearby on fire damaged pines, I think it’s possible that food sources would be sufficient in cypress-tupelo swamps under certain conditions. This relates, at least indirectly, to issues that have been addressed in the “Bits and Pieces” series. Stay tuned for the final installment.