Cornell's "robust" Ivory-bill sightings all occurred in a tiny (4 square kilometer) area in a strip of habitat just south of 17 on this satellite photo. (Note that restaurants like McDonald's and Taco Bell are less than five miles away in Brinkley.)
As you can see by the scale on the map, that strip is roughly a mile or less in width! I think it's astonishing that people spin this as a vast, remote swamp, and that the press can actually call this "America's Amazon"...
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12 comments:
Can Cornell really be focusing its efforts on this area, from what you know? I mean even the believers think the bird found was just an unmated male, travelling the river valley and originating from some big swamp that isn't on your map. I mean if you travelled the river valley down the middle, you could hear an IBW on either side, on most days.
I can't believe Cornell would be focusing that much effort and hordes of science, volunteers, etc, on such a narrow strip of land.
Or should I believe the experts are really dumb and would neglect La, Mississippi, etc? Does the whole Delta area look like this too?
It would need to be 3 times wider
just to warrant any searching.
Paul - New Paltz, NY
Just scrolling the map you sent shows larger pieces of fairly connected land to the SW. All of it fairly hemmed in with agricultural lands not suited to any forest bird.
For so much hype about the Cache River... it's really a linear park!
Paul Sutera, New Paltz, NY
So why would the "robust Ivory-bill sightings" all be clustered in such a tiny, nondescript area? And why were the looks all fleeting glimpses, with very few fieldmarks seen? Why weren't the birds vocalizing; why can we never clearly photograph an Ivory-bill, etc etc?
As I may have mentioned before, I think the information at this
link is a critical clue:
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Arkansas State University professor of wildlife ecology Jim Bednarz has seen several pileated woodpeckers with an abnormal amount of white wing feathers in the Cache River refuge. With Team Elvis, he pursued three birds that showed a flash of white in flight and white on their backs as they were perched. All were pileated.
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I rather think few people can keep all the chunks of swamp forest straight.
Cache River, White River, Big Woods, Pearl River etc. There *are* big chunks of swamps just big enough to support a few pairs. Not the Cache River preserve though.
As far as the IBW not making noises? Read A C Bent on that one. Only Tanner says they call occasionally while on the wing. And Elvis is always on the wing, according to skeptic doctrine.
Ok I admit it's all rather convenient that they don't call, sit still, drum or show their faces, dig nest holes, and don't leave feathers or dead bodies shot by hunters thinking they got a duck!
Paul - New Paltz, NY
Errr...yeah, few but "experts on southern swamps" have a grasp of how large is the South, "few people can keep all the chunks of swamp forest straight", etc., etc. If the world didn't have Cornell and the rest of the "Noo Yawkers" to keep straight the rest of the rubes...?
"Big chunks of swamp just big enough to support a few pairs"? Hey, there are "big chunks" of prairie and forest "just big enough to support a few pairs" of mastodon, but it doesn't mean that they actually exist. Neither does it mean that there would be a self-sustaining population, either.
Of course ready habitat doesn't mean
anything. There's plenty of habitat for the Bachman's Warbler, but it is likely gone. The point I'm trying to make is that various people are saying "vast wilderness" and meaning different things. Tom clarified nicely that the Cache River area is no wilderness. You can easily scroll the map and find areas that ARE 15 mile wide forests w/out being a Northerner, an Ivy League graduate, or even a "rube."
Tom's discussion focused on the areas that have had the most robust sightings. And now we know a lot
from the map he linked us to.
Some people have stated that there is no vast wilderness down there and made strong arguments based on IBWO habitat sizes and available forests. You can scroll the Google maps and while there's no substitute for being a Southerner
with swamp experience (like the one's who corresponded with me),
it's instructive...draw your own
conclusions.
As for New York, there's more wilderness here than
in the delta, the Big Thicket, the Cache River, the White River, the Big Woods and the Great Smokies combined. And Ithaca (home of Cornell) is a long way from the Big Apple (noo yawk accent).
Paul - New Paltz, NY
Simple explanation as to why the robust sightings were all in Bayou de View: Because that is where they were looking. When you are trying to confirm a sight record, do you say "Oh the habitat looks better 40 miles away I'll look there"?? No, you go where the bird was last seen. And if it is seen again in the same area you keep looking there.
Ground surveys (published in the abstracts of the large woodpecker symposium) in fact found a very high density of standing dead wood in Bayou de View, as well as very high densities of other woodpecker species, both comparable to the mature bottomland hardwoods farther south. It may not be extensive enought to support a breeding pair on its own, but it certainly could constitute a fruitful foraging ground.
OK, so you criticize the sightings for all being in Bayou de View, and you criticize the ARU results for not being in Bayou de View...
You are correct. When searchers found real Ivory-bills back in the 1930s, the evidence was very strong and "concentrated": within a small area, they saw them very well and took clear photographs of them; they also heard their double-raps, the kent calls and the loud wooden wing sounds.
By contrast, the "evidence" from Arkansas is very weak and scattered: fleeting glimpses in an area where multiple abnormal Pileateds were seen, but little or no directly associated sound evidence; kent-like calls tens of miles away, in an area where Blue Jays were observed making kent-like calls; isolated double-raps elsewhere, etc.
In my opinion, the "body of evidence" from Arkansas is a very good match for the "false positive" evidence that should be expected, given the hypothesis of an enormous search effort and no Ivory-bills present.
Regarding the high density of
standing dead wood in the Bayou
de View area; this would be
attractive to Ivory-bills if
the trees had recently died. Ivory-bills fed on trees that were
dead from 2-4 yrs (est) because
that is the time when the large
larvae of wood boring beetles
(Ivory-bill food) was present beneath the bark. Beyond that
time the larvae burrowed deeper
into the tree and were no longer
present just beneath the bark
and were no longer accessible
to Ivory-bills. The Ivory-bill
did burrow sometimes in "ripe
wood", however, the vast
majority of its subsistence
was found just beneath the
bark of recently dead trees.
No data is given in the abstract concerning the condition of the dead wood. The total volume is compared between various habitats.
The abstracts from this symposium are available online as a .pdf file:
http://nature.org/ivorybill/files/symposium_abstract.pdf
or if you want the html Google cache simply google for "large woodpecker symposium" and it should be among the first few hits.
The papers concern a variety of species, not just Ivorybills.
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