Monday, May 17, 2010

-- Quote, Unquote --

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Repeating once again just a few of the passages from Tanner's classic monograph on Ivory-billed Woodpeckers:

"The chief difficulty of the study has been that of drawing conclusions from relatively few observations, necessary because of the extreme scarcity of the bird. My own observations of the birds have been entirely confined to a few individuals in one part of Louisiana... the conclusions drawn from them will not necessarily apply to the species as it once was nor to individuals living in other areas. The difficulty of finding the birds, even when their whereabouts was known, also limited the number of observations. Especially was this true in the non-breeding season. With these considerations in mind, one must draw conclusions carefully and with reservations."

"The dominance of cypress in the bird's [Florida] habitat is a condition not found outside of the Florida region. Another difference is that Ivory-bills in Florida frequently fed in the pine woods bordering the swamps, something that has never been recorded in the region of the Mississippi Delta and only rarely elsewhere."

"There is no one type of forest that is the habitat of the Ivory-billed Woodpecker; it varies greatly in different sections of the bird's range."

"One condition is characteristic of all Ivory-bill habitats, namely, that other species of woodpeckers are common or abundant in those places."

"Hunting for localities where Ivory-bills were, and in those localities trying to find the birds, was like searching for an animated needle in a haystack."

"Winter and early spring are the only good seasons for investigating Ivory-bill habitats. Leaves are then off the trees, allowing good visibility and hearing, the birds are quite active and noisy, and the cooler weather makes work in the woods pleasant. Work in the summer is practically a waste of time because of the dense vegetation, silent birds, and depressing heat."

"Ivory-bill sign shows as bare places on recently dead limbs and trees, where the bark has been scaled off clean for a considerable extent. Pileateds do some scaling too, but it is usually confined to smaller limbs and to those longer dead. Freshness of sign can be judged by any appearance of weathering, which will soon turn bare wood a grayish color. Extensive scaling of the bark from a tree which has died so recently that the bark is still tight, with a brownish or reddish color to the exposed wood showing that the work is fresh, is one good indication of the presence of Ivory-bills."

"All the Ivory-bills that I have ever seen I located first by hearing them call and then going to them."

"Considering the maximum abundance of the Ivory-bill to have been one pair per six square miles, of the Pileated to be six pairs per one square mile, and of the Red-bellied to be twenty-one pairs per one square mile, the relative abundance of these birds would be one Ivory-bill to thirty-six Pileated to 126 Red-bellied Woodpeckers."

"Considering all the evidence, I believe that Ivory-bills were not sedentary birds, but sometimes wandered considerable distances....
Furthermore, the Ivory-bill is well adapted to traveling for long distances. It is a strong flier with a fast flight for a woodpecker, and individuals have been observed feeding over several square miles."

"Ivory-billed Woodpeckers usually travel in pairs; at least that is the number most often observed. Single individuals seen are usually unmated birds."

"Ivory-bills probably stay paired throughout the year and mate for life... No matter what season of the year, Ivory-bills have almost always been observed in pairs, indicating that they do not separate during the non-breeding season."

"The Ivory-bill's habit of feeding and living almost its whole life in and near the tops of trees makes it very unlikely that any mammal could prey on one."

"There is further evidence that food is the decisive or 'limiting' factor for Ivory-billed Woodpeckers. Several times in various parts of Florida many trees have been killed by fire, storms, or other causes. Ivory-bills have appeared in these places and fed upon these trees as long as the borers beneath the bark were common, and then they have disappeared, moved elsewhere."

"The flight of the Ivory-bill... is strong and usually direct, with steady wing-beats. They can take flight quickly either from a perch or from a hole, springing into the air with very little descent before getting up to speed. They often fly above the tree tops, dodging the trees with very little deviation from their course. In the thick woods it is ordinarily difficult to tell how far the Ivory-bills fly, but I am quite sure that their flight is often extended for half a mile or more."

"Ivory-bills are not social or gregarious birds; they have apparently always lived in solitary pairs, and as long as the birds can mate, they are capable of reproduction and increase. With small numbers, inbreeding could occur, but there is no evidence that this would be harmful. Large numbers are not necessary for the continued existence of the Ivory-bill."

"When the food supply is sufficient, the woodpecker is probably resident or sedentary, with a feeding range from three to four miles across. There is considerable evidence that pairs or individuals sometimes move long distances in search of forests supplying an adequate quantity of food."

"The daily activities of the woodpeckers during the non-breeding season follow a fairly definite pattern. Beginning about sunrise, they feed and move actively during the early morning; they are quiet during the middle of the day, feed again in late afternoon, and then end the day by going to roost about dusk."

"The only factors discovered which have definitely affected the numbers and distribution of the species are the quantity of food available to the birds and their destruction by man."

and reiterating one last time,
"...one must draw conclusions carefully and with reservations."
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13 comments:

fangsheath said...

Tanner curiously overlooked McIlhenny's observations, published by Bendire in 1895:

"In the cypress swamps adjacent to Avery's Island, Louisiana, these noble birds are still quite common....The nest is generally placed in a cypress or tupelo gum tree...."

I have often wondered what led Tanner to make such broad claims about the bird's habitat preferences in the vast Mississippi floodplain, since he never saw any of them outside the Singer Tract. It is beyond plausibility that the 12 square miles of cypress/tupelo swamp east of Avery Island was the only such forest occupied by the birds in all of that region.

Mark said...

While summer is challenging for at least some of the reasons given, it seems Tanner was engaging in a bit of hyperbole. A quick glance through his list of records indicates that birds were seen and collected year-round. I think limiting the search search season to late fall-winter-early spring has been a mistake.

What I find problematic about Tanner's writing is that while he repeats the standard disclaimer about not drawing conclusions from such limited data, he often seems to have done just that. That's not to diminish the importance of his work, just to point out an internal tension.

concolor1 said...

Hmmm . . .

The Ivory-bill's habit of feeding and living almost its whole life in and near the tops of trees makes it very unlikely that any mammal could prey on one.

The flight of the Ivory-bill... is strong and usually direct, with steady wing-beats. They can take flight quickly either from a perch or from a hole, springing into the air with very little descent before getting up to speed. They often fly above the tree tops, dodging the trees with very little deviation from their course. In the thick woods it is ordinarily difficult to tell how far the Ivory-bills fly, but I am quite sure that their flight is often extended for half a mile or more.


Gotta make sure Mike Collins's critics see these two...

spatuletail said...

Why?

He's proved time and again that he doesn't have a clue. You can't castigate the entire birding community as incompetent and know-nothings when all you do is put up poor video of Red-headed Woodpeckers as your 'proof'.

And talk of "drawing conclusions from limited data" is outrageous given what people on here do.

Isn't anyone going to calculate the population size from the available habitat and the number of what you deem to be acceptable sightings or encounters in searched areas? Should be enormous.

concolor1 said...

Boy, spat really has a perverse fetish for strawmen, doesn't he?

I wish he'd look at Collins's other videos and MC's gripes about getting his data published. Worth considering; might help him shed that closed mind, although I'm personally doubtful.

But don't look at Mark's Project Coyote shots; it might shake up some paradigms considerably. I gave one of those a second good looking over the other night, and the claim of a "white shield" on the lower dorsal area appears legit. And the absence of red artifacts and the size measurements are fairly persuasive.

Spat, you've convinced yourself all the other eye-witnesses are lying, and apparently some of your kind have a following. Against such implied meta-insults, a bit of generalized hostility is understandable. Some of us don't suffer opionated fools gladly. Reminds us too much of our own adolescence.

And it's particularly rich the way accusations of rudes are included when you freely toss about insults about how outrageous our actions are. More entitlement beliefs...

As I've said repeatedly, narcissism in a nutshell...

Anyway, where'd you learn that junk science version of that "statistical" technique anyway? It might be useful in arguing against UFO's, but the credibility of green men claimnants is tempered by knowledge of Einstein's physics. IBWO's are under no such constraints.

Spat: "Those can't be pictures of IBWO's. The bird is extinct. I know, because I said so!"

spatuletail said...

Thanks for all those insults that don't even remotely address how rare birds should be documented. Again.

So, how do Mike Collins' records of other rare birds fare? Do they get accepted? Do other people see them? What's his track record like? What do other reputable birders in his home area say?

re my amateur attempt at stats: Project Coyote finds IBWOs exactly where they look, so does Collins, so does Geoff Hill, so does Fred Virazzi. These birds are everywhere, surely?. Give me your best approximation based on those birds above being good records and the available / unsearched habitat left.

"paradigms, artifacts, meta-insults, entitlement beliefs,
narcissism, junk science, Einstein." Fantastic.

Mark said...

I'm not going to engage in speculation (statistically informed or otherwise) about numbers. I don't know what you mean by "finds IBWOs exactly where they look," but it seems intended to insinuate something. I can't speak for others, but I've spent many weeks looking in a lot of promising places without finding ivorybills or anything like the abundance of suggestive foraging sign that we've found in our search area, much of which matches Tanner's description Cyberthrush quoted above. As I wrote on the Project Coyote website: "Collectively, team members have hundreds of days experience in the field and have searched in five states. We all agree that the foraging sign in our search area far surpasses anything we have seen anywhere else, in terms of quantity (concentration in a relatively small area) and quality, based on its resemblance to what Tanner described and photographed in the Singer Tract."

Moreover, I've now spent approximately three weeks in our search area (including one week alone, during which time I didn't see or hear anything.) I've had one sighting and three auditory encounters, two of which occurred on the same day - not exactly a high encounter rate. In all instances, others were present. Say what you will, but no one (Mike Collins included) has ever suggested this is easy.

As for unsearched habitat, I can assure you there's far more of it than you'd think. Spend a few days in Louisiana sometime and see for yourself. Our team leader would be happy to show you around.

prairiewolf said...

"Project Coyote finds IBWOs exactly where they look...."

Come to Louisiana Splat...I'll take time off from the day job to show you around.

Past that, the fruitless back and forth, while sometimes amusing, really has no value. Time on the ground, observing PIWOs and other woodpeckers has value, even if you are correct and the ivorybill is extinct. If you are wrong, and the ivorybill is extant, then there is more value in observation of other species, because at some point, the behaviors have to diverge, and eventually a consensus about ivorybill "sign" will emerge. The simple fact is that I merely want to establish, by observation, that PIWOs (or Red-bellies, or Cajun leprechauns with a sense of humor, two sticks and a clairnet mouthpiece...) either are, or are not the source of the unusual scaling and large, strangely shaped cavities, as well as the source of the hard to explain away camera trap photos. If the source of these phenomena is not Ivory-billed Woodpeckers, so be it; science will be advanced by establishing that it is within the capacity of species "X" to perform these actions which are suggestive of ivorybills according to the historical record.

BTW...It'd be really nice to "find IBWOs exactly where I look" because then there wouldn't be so much time wasted on non-productive territory.

With great respect for your anonymity...

Frank

Unknown said...

spatuletail, you realize that the people who announce that they have encountered putative Ivory-billed Woodpeckers aren't the only ones looking. Lots of people don't find the birds, but they don't bother putting up a website to say "Nothing to report!" Note also that the Project Coyote crew didn't randomly choose the spot where they are doing their field work - they are following up on reports from others.

Bill Pulliam said...

Spat, you said "He's proved time and again that he doesn't have a clue. "

Interesting statement coming from you, considering that in comments on an earlier post you made it clear that you are not even aware that the Pileated Woodpecker is not a Campephilus, but is in fact in an entirely different and rather distantly related genus.

Are you even a birder?

spatuletail said...

Yes, Bill. An oversight on my part. Apologies. I've seen most Campephilus and a large number of other peckers over the globe

Now, is anyone going to address the point that many people who search seem to find (see above) despite the oft-repeated claims of mega-elusiveness and difficulty to find the bird. And what does that mean for the numbers given the available unsearched habitat?.

I think I'll leave you good folks alone to your searching for a while. Don't be shy about posting photographs of all those IBWOs you find. Fame awaits.

When the birding gets weird, the weird turn pro.

Mark said...

>>I've seen most Campephilus and a large number of other peckers over the globe.

Easy to say when you're anonymous. Forgive me if I'm skeptical. I'm sure the invitation to Louisiana stands. You seem to have the resources to make the trip, so come on down.

I'm not big on alluding to The Bible, but something about motes and beams seems appropriate here, especially when a pontificating, self-appointed guardian of science, ornithological excellence, and BRC standards displays such glaring ignorance, about something so basic and then thinks that offering "apologies" will explain it away.

Hilarious.

Bill Pulliam said...

Spat -- all the things you keep harranging about have been addressed many times, by many diffferent people, and in many different ways, on blogs, in the peer-reviewed literature, and everywhere in between. Like a good talk radio or cable news mouthpiece, however, you keep pounding out the same slogans in true "WHERE"S THE BIRTH CERTIFICATE" fashion, regardless of what has actually been said.