What’s in the Cavity? A Possible Second Bird in a Couple of Old Trail Cam Photos

Regular readers are no doubt familiar with some of the images shown below. The “neck bird”, which was photographed in our old search area in August 2009, has been discussed in a number of posts. I think it likely shows a female Ivory-billed Woodpecker, something that became clearer once I satisfied myself that what appeared to be red in the crest (in the wrong place for either Pileated or ivorybill) was likely an artifact and that the crest appears to be all black, as shown in the enhanced image below. The original captures (the first taken a minute before the neck bird appears and the second showing the neck bird) are immediately below that for those who haven’t seen them.

IMG_1096-Edit-Edit-Edit-Edit-Edit-Edit-Edit-Edit-EditTopaz+processed+neck+bird+copy-magic copy 2

Processed Detail of Image 1096, August 11, 2009

Years after the capture and probably after the first post about this image in 2014, I noticed that an object suggestive of a light colored bill was visible in both frames, apparently protruding from the lower cavity in the snag to the right of center. While I have shared this information privately with a number of people and did a vague Facebook post about it a couple of years ago, I’ve hesitated to blog about it or discuss it in detail. That changed after I showed it to Jay and Erik before we parted company on my last trip to Louisiana. When Erik suggested that the object might be a vine or some other intervening vegetation, I decided to go back through my files. I discovered that Frank had sent me several additional captures from the same deployment. I examined these frames and found that the apparent bill was absent from all of them.

 

Below are details from frames 1095 and 1096 showing the apparent bill, which changes position slightly from one frame to the next. The time lapse interval between images was 1 minute. Again, the cavity in question is the lower one (below the fork) in the snag to the right of and behind the one on which the neckbird is seen in 1096. These snags are black willows (Salix nigra), and the neck bird snag (with the large cavity apparently being used by a squirrel) fell between November 2009 and January 2010. I’m also posting the close-ups in tiled mosaic format so they can be viewed side-by-side.

For this round of image processing, I used Let’s Enhance, which enabled me to retain a large format for cropped and zoomed versions.

IMG_1095-Edit-2-EditTopaz+processed+neck+bird-magic. copy

Detail from 1095 – Note apparent light colored object (possibly a bill) apparently protruding from an bisecting the lower cavity

 

IMG_1096-EditTopaz+processed+neck+bird-2-magic copy

Detail from 1096, captured one minute later. Note slight change in position of the possible bill.

Next are two details from images captured a few days later. The possible bill is nowhere to be seen. The same is true for the other captures from this deployment. Thus intervening vegetation and artifact can be ruled out.

2135DetailEnhanced

Detail from image 2135, captured August 14, 2009. Note the absence of the apparent bill that appeared in images 1095 and 1096 captured three days earlier.

2507DetailEnhanced

Detail from Image 2507, captured on August 16, 2009. Again, note the absence of any object in the lower cavity.

To summarize, the following two photos show what appears to be a bill in the cavity:

2009-08-11 7:48 am  (image 1095.jpg)

2009-08-11 7:49 am  (image 1096.jpg – the neck bird photo)

The following photos show a cavity with no apparent bill:

2009-08-14 6:19 am

2009-08-14 6:20 am

2009-08-14 6:21 am

2009-08-14 4:06 pm

2009-08-14 4:07 pm

2009-08-15 6:20 am

If this is a bill, it appears to be large and light colored, consistent with Ivory-billed Woodpecker. Both Erik and I noticed that, in frame 1095, a topmost part of the white dorsal stripe also may be visible. When Jay first saw the photos, he was reminded of the Neal Wright photos from Texas. Some images from the Singer Tract also come to mind.

 

Thus, this apparent bill resembles those of known ivorybills in cavities – in size, shape, orientation, and contrast. It is present only in frames 1095 and 1096 (the latter of which shows another possible ivorybill); it changes position over the course of a minute, from one frame to the next. There is no way to be sure images 1095 and 1096 show an Ivory-billed Woodpecker in a roost hole, but these facts, especially taken together, suggest that they may.

When I look back at what transpired in the old search area between August 2009 and November 2010, when the adjoining parcel was logged, it’s extraordinary. I may revisit those events in a future post or two.

For now, I’ll close by tying this into the Bits and Pieces series. The old search area is not one that would be deemed suitable under most habitat models. The images above were captured in a stand of black willows at the edge of a bean field. The other trail cam capture, where I had a sighting, was also within perhaps 30 yards of that field. When I look back at my assessment of the habitat from the time, I think I somewhat naively overstated its quality; however, there was a good deal of dead and dying timber, and it was in close proximity to several much larger habitat patches. If we did indeed capture ivorybills with our trail cams, their presence in this area may point to how the species has been able to adapt to more fragmented habitats.

Thanks to Erik Hendrickson for his input on this post and his help in making it clearer.


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).

November 2021: Edited to add the Wilson record for Winchester, Virginia is apparently erroneous.

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.