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Trip Report, Part One: March 31-April 5, 2015

As always, my time in our search area was very productive – inspiring new insights and ideas and producing suggestive but inconclusive evidence that Ivory-billed Woodpeckers are present in this location and have been for years. The weather was considerably more cooperative this trip than on the two or three preceding ones, although temperatures edged toward the uncomfortable – mid 80s and humid from Tuesday-Friday – and rain limited field time on Saturday and Sunday. I was alone from Tuesday-Thursday, and Frank Wiley joined me from Friday-Sunday. Later this week, I’ll post a day-to-day log that includes more about possible encounters and some additional images,

For reasons that should become clear, we are starting to think there may be a home range in an area of over four square miles (and possibly considerably more than that), much of which we have not yet explored, and some of which is very difficult to reach – a two mile walk from the nearest road and bisected by deep sloughs and streams. We have some reason to suspect that this range has been used for a number of years. This is in very mature bottomland forest, logged between 1905 and 1915, and it includes the stand of sweet gums where we found a cavity cluster last year.

Also on this trip, we did more experimenting with playbacks; I actually began the experiment shortly before I left for Louisiana, with a Pileated Woodpecker in my yard outside New York City. She responded with considerable agitation to my playback of Pileated calls and drums – calling and flying over at very close range while looking directly at me. She did not react at all to playback of ivorybill calls and pounding from the Singer Tract (the iBird Pro selections). Several species in our search area seem to react to ivorybill playbacks. Pileated, Red-bellied, and Red-headed Woodpeckers frequently react with drumming and scolding. In one instance, a calling Pileated Woodpecker went silent and flew away immediately after a playback. Barred Owls will often call immediately after, as will American Crows. In one case, a pair of crows came in to within 80 feet, apparently to investigate; in another, a Red-shouldered Hawk did the same.

There were three instances of possible ivorybill interaction with or response to playback. Two of them were very weak possibles, meriting only this passing mention. The third was a little more interesting and will be discussed in the day-by-day account. We will continue the experiment, both in Louisiana and New York (to see if and how various species react). We’ve recently been informed, by “Motiheal” from ibwo.net, that a Red-headed Woodpecker in Virginia approached in response to the playback of five kents.

One of the reasons we’re optimistic about having pinpointed a home range is the abundance of feeding sign in the area. In addition to the work sign from this area discussed in previous posts, there’s an abundance of older work, like this scaling on a hickory snag. OldHickory3 oldhickory2

Extensive scaling on an older hickory snag. Work goes from near the base to near the top. Atypically, some of the work at the base appears to be more recent than the rest.

Extensive scaling on an older hickory snag. Work goes from near the base to near the top. Atypically, some of the work at the base appears to be more recent than the rest. While the work is not fresh, and the bark has started to loosen, it is still within the decay stage described by Tanner as being preferred by ivorybills, as shown by the presence of twigs.

According to Tanner (p. 47), “Trees and limbs almost two years dead have lost almost all twigs, some small branches, and bark is loosened on some small branches.” Of course, the decay process is not as linear as Tanner’s description implies, and scaling of bark itself hastens the loosening of whatever remains. Thus, on scaled branches and boles, bark is likely to have loosened considerably unless the work is very fresh. Still, the presence of leaves and/or twigs is a strong indicator of recent death, perhaps even more so on blowdown, for which the decay process is likely hastened by proximity to the ground. In terms of more recent work, I found two sweet gums with sign on large high limbs, perhaps the most dramatic scaling that closely matches Tanner’s description we’ve found to date. Not only is it very extensive; the scaled limbs are quite recently dead. While it’s not possible to test the tightness of the bark, the presence of leaves in the case of the more recent scaling and twigs with buds in the case of the somewhat older work suggest that the limbs died within a six months to, at most, two years. SweetGum1 SweetGum2 It has been suggested that ivorybills are largely birds of the canopy that seldom if ever feed near the ground and that this behavior might account for the difficulty in obtaining clear photographs. Despite the fact that Allen and Kellogg observed a female bird feeding on the ground like a Flicker, and Tanner himself reported observations of foraging close to the ground, the idea that the species is limited to the canopy has become a kind of conventional wisdom. As I’ve discussed in previous posts, I don’t accept this notion and much of the feeding sign we’ve found has been low on standing trees and snags and on blowdown or slash. In the last trip report, I discussed feeding sign found on recently downed sweet gums (just outside of what we believe to be the hot zone, although possibly within it if it is larger than we currently suspect). On this trip, I found over two dozen examples of extensive bark scaling on downed sweet gum tops and limbs. IMG_0888 DSC00076 DSC00070 DSC00074 This work was so commonplace that photographing additional examples seemed redundant. In all cases, the blowdowns were recent and involved very freshly dead wood. At least some leaves were still attached, making it likely that these limbs and tops had fallen in the last six months to one year. In the hot zone, I found only two sweet gum tops or large limbs that had not been scaled. Most of the scaling was recent to very fresh, probably one or two days old in one instance (unfortunately, it had rained the night before, so any scat had been washed away.) I do not believe that all of this is the work of ivorybills. Nonetheless, I suspect that much of it is, due to its abundance and extensiveness and in light of Tanner’s study and the preference he found in the Singer Tract ivorybills for recently dead and dying sweet gums (this even though I believe Tanner overstated this preference and did not sufficiently account for specific conditions in the Singer Tract).

I did not find this type of work in brief visits to areas outside the hot zone, where it was ubiquitous; nor have I seen anything quite like it elsewhere. I did not see anything like it on other species of downed trees; the only partial exception was some scaling on longer dead parts of a live downed hickory. As an aside, it’s worth mentioning that the species of hickory in our area were not present in the Singer Tract, although their congeners, pecans and water hickory were. Unlike Tanner, we’re finding scaling on hickories that likely exceeds their relative abundance. We’re also finding considerably less scaling on various oak species.

In addition to the work on freshly downed sweet gums, I found two standing, recently dead young sweet gums that had been worked on in unusual ways. Both showed signs of infestation by insects that bored into the heartwood. Both had been very heavily scaled, one with minimal excavation only around the insect tunnels. The other had been hacked up in a way that, in the words of several people, looked as if someone had taken a hatchet to it; the wood was hard and not at all punky. Whatever did this work chopped through a small branch to the point where it broke off and almost severed the top of the tree as well.

SmashedSaplingLongShot SmashedSGSapling IMGP0564

Close-up of 2" diameter limb that apparently broke off while being fed upon

Close-up of 2″ diameter limb that apparently broke off while being fed upon

In his report on Cuban ivorybills, George Lamb described something similar:

Soon after we observed a female ivory-bill . . . feeding on the dead branch of a Hilacho tree (Torrubia obtusata) in a small stand of hardwoods. Suddenly the branch broke off while she was still perched on it . . . The Hilacho limb previously mentioned as breaking while being fed on, represents a type of feeding which was neither scaling nor digging. The limb was vertical and had probably originally been about three inches in diameter. Possibly it had once been scaled, but when recovered showed evidence of feeding to the extent that hardly anything was left. The wood was very punky and hand been chipped away from the perimeter to of the limb all along it’s 2 1/2 foot length. The chips, some of which we gathered, were long and splintery appearing, and were riddled with beetle larvae “tunnels”. 

Our broken branch is approximately 2″ in diameter, while the top appears to be more than 3″. Unlike the Hilacho tree, the wood on this sweet gum was hard, not punky.

While I suspect that some of the work on these trees, the very targeted work on the limbs (small rectangular scaling/digging), may have been done by Hairy Woodpeckers, the bulk of it is extremely unusual, inconsistent with any Pileated Woodpecker work I’ve ever seen and with Tanner’s description of that species’ foraging preference for longer dead wood; the type of prey is consistent with what would be expected for ivorybills. While the work on ‘hatcheted’ sapling doesn’t meet the diagnostic criteria we’ve developed over the years, we think it highly likely that this is Ivory-billed Woodpecker work. The scaling on the other small sapling is generally consistent with our criteria, although it has some very limited excavation, clearly aimed at expanding existing tunnels, rather than digging into the wood in the manner typical of Pileated Woodpeckers. Top of Snag LittleSapling ExitTunnelExpanded IMG_0876_2 Again, from the Lamb report: At one point she was only about 25 feet away while she was feeding around the base of a small pine. She began working “barking” this tree around 30 inches from the ground and slowly worked her way up to the top.

Stay tuned for the second installment, which will also include details of a sighting Frank Wiley had on Friday, April 3.

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6 Comments on “Trip Report, Part One: March 31-April 5, 2015”

  1. Great site, and I wish you guys well.

    The “hatcheted” feeding sign on that smaller tree is quite interesting; I’ve not seen anything similar. I’m wondering about your alternative hypotheses for that sign. I’ve got some photos of unusual feeding sign in central OK that are probably PIWO (might be RBWO) that might be useful to you for comparison of what it’s possible for sign of our other woodpeckers to look like. Also, is their any chance that could have been squirrels or porcupines chewing into the wood? (Unlikely I know, just trying to consider all options.)

    Finally, if you ever come across suspected IBWO feeding sign that’s really fresh, then almost certainly there would be saliva somewhere on that punky wood that could potentially be collected and analyzed. Have you discussed such possibilities with forensics/genetics specialists?

  2. Thanks Tim! The area is hundreds of miles from porcupine range, and the appearance of the wood is inconsistent with its having been chewed – no incisor marks, etc. It’s pretty clear that it’s woodpecker work. For most of what we think is suggestive (or that we hypothesize is diagnostic), the only plausible alternative is anomalous PIWO work, but I see that as far-fetched for a number of reasons, anatomy in particular.

    We’ve had some very cursory discussions about this approach to DNA collection testing, but at this point, we don’t know how we’d go about obtaining a sample and what would be usable; cost is also a consideration. While I can’t be 100% certain, I believe the only work we’ve found that might have been fresh enough (ie. done the day before, not within a few days or weeks) is the hickory on the homepage.

  3. Fantastic photos. The broken branch work and the work on the small tree is very compelling. Not to mention the concentration and amount of scaling that you’ve found. Love reading the blog.

  4. Concentration and quantity are both significant. Glad you enjoy the blog and that you picked up on that important detail.

  5. Frank asked me to add the following:

    We kept a Reconyx on the tree on the home page for several months, and we had at least one short visit from a PIWO and also from a HAWO. The sequences are discussed in this post: https://projectcoyoteibwo.com/2013/05/27/extensive-scaling-on-a-live-hardwood/; it was clear that a little “peck and glean” work was all that took place during the PIWO visit. However the long sequence of a Hairy Woodpecker showed the bird scaling a quarter to fifty cent sized piece of bark directly over an exit tunnel. I remember calculating that working 24 hrs a day at the speed observed, that it would have taken a single HAWO some thirty days to scale that much of the tree. While it seems a bit ludicrous, I think, if I were asked what the alternate hypothesis would be, that maybe anomalous HAWO work (in terms of square units per unit time) would be the best fit – but I still find the scale observed off by an order of magnitude.

  6. Thanks for that additional info.


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