"....The truth is out there."
-- Dr. Jerome Jackson, 2002 (... & Agent Fox Mulder)
“There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.”
"All truth passes through 3 stages: First it is ridiculed. Second, it is violently opposed. Third, it is accepted as self-evident."
-- Arthur Schopenhauer
Friday, October 26, 2007
Gary Graves posted the following review of Noel Snyder's latest monograph on Ivory-billed Woodpecker decline on the Arkansas listserv today (the monograph argues that hunting/collecting, NOT forest ecology, may have been the greatest cause of IBWO decline) :
"Noel Snyder (a retired USFWS biologist and the chief architect of the successful California Condor recovery program) has just published a 57 page monograph entitled, "An alternative hypothesis for the cause of the Ivory-billed Woodpecker's decline." Snyder's persuasive monograph counters the prevailing wisdom on Ivory-bill ecology (largely derived from Tanner's work with the remnant population in the Singer Tract in the late 30's and early 40's) and the underlying causes for the species' apparent extinction in the United States. In-depth research of historical archives and letters suggests that Ivory-bill population densities in the 19th century were much greater than currently believed (perhaps nearly as common as Pileated Woodpeckers), that Ivory-bills were not foraging specialists on recently dead trees in virgin forest, and that population declines were not related so much to habitat destruction as to direct human depredations: (1) subsistence hunting (yes, people used to eat large woodpeckers); (2) sport and curiosity hunting, and (3) the zealous activities of commercial collectors who procured Ivory-bills for private collectors and museums. This later activity was mostly restricted to Florida populations between 1880 and 1910 (only five museum specimens are known from Arkansas-collected from 1844 to 1884). The impact of sport and curiosity hunting alone was probably enough to account for the extirpation of Ivory-bills in the Singer Tract (Louisiana) and many other locations within its historic range. Snyder draws parallels between the plight of the Ivory-bill and the California Condor and Whooping Crane (both of which were nearly exterminated by curiosity hunting). Snyder also emphasizes the fact that there was little evidence that a shortage of food or selective logging was responsible for the Ivory-bill's decline. Cuban Ivory-bills, for example, persisted for over 50 years in a heavily cutover region. Although severe logging (clear-cutting) is undoubtedly detrimental to woodpecker populations, Ivory-bills in the United States disappeared from many locations decades before the virgin timber was cut. Snyder hypothesizes that the most detrimental affect of logging was to facilitate the entry of humans (with guns) into formerly remote and inaccessible areas. There are several explicit and implicit messages in Snyder's synthesis. Perhaps the most poignant is that pure human curiosity (the desire to examine the magnificent bird in the hand) might have led to the extinction of the Ivory-bill. The list price ($25) of Snyder's monograph is rather steep but it is a must read for ARBIRDERs with a strong interest in Ivory-bills. The monograph can be obtained from the Western Foundation of Vertebrate Zoology: http://www.wfvz.org
I began making this very same argument over 6 years ago privately to people, as well as including it in a post at this blog over two years ago here. (In saying that, I'm NOT at all inferring that Noel stole my idea, but rather that it is interesting that two individuals, stepping back from the orthodox IBWO gospel, and looking freshly and open-mindedly at the evidence, ended up approaching the same hypothesis.)
ADDENDUM: a timely new article by Geoff Hill (actually written last May) is now online in the latest edition of Birders World Magazine:
ADDENDUM II: Well lo-and-behold!, now someone over at BirdForum has found a link to an old August 1997 BirdChat post by Mike Collins also alluding to the possibly overlooked and underappreciated effects of hunting/collecting on the Ivory-bill (he's got me and Noel beat by a longshot):
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