...Given that the only available data show a wide range of variation, and do not include the type of flight shown in the Arkansas video, there is simply no basis for saying categorically that the bird is flapping too quickly to be a Pileated Woodpecker...
Monday, March 20, 2006
David Sibley on wingbeat frequency
Here's an excerpt from today's post by David Sibley on ID-Frontiers:
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The issue of wingbeat paterns are the last remaining details in which Cornell & the rest of the searchs group are grasping to in order to validate this as an Ivorybill. The whole basis of this depends on past measurements made thru studies of Ivorybill's in a normal, un-harrased, content evrioment. In the video of what has been presented as an Ivorybill, one is suppose to observe a bird taking flight to retreat from possible danger. If a normal Ivorybill is suppose to fly at a faster rate than a Pileated, it would be common thinking to presume an Ivorybill would increase it's normal flight pattern to quickly advoid possible danger. If this could be persumed, then an Ivorybill filmed under the conditions this bird was filmed under would not be fleeing at a normal rate, but a much faster rate than the one documented. Now, presuming a Pileated does have a slower flight pattern, one could only persume the same would apply. If fleeing from danger, it's flight patterns would also increase. If this happens, it's wingbeats could increase to a rate compairable to that of a normal Ivorybills flight patterns under passive flight.
Common thinking must be used here. All animals in nature increase their normal modes of locomotion when threatened with danger. With this in mind, it is only lodical one would have to persume the bird in the film is flying away at a higher rate than normal because of the danger factor present from the people who are present at the time. So only one of two conclusions can be made here. Either 1,the bird is the video has to be an Ivorybill flying away at a normal, content, business as usual flight pattern even with danger present, or 2,the bird is another Woodpecker with a much slower noraml flight pattern leaving the presence of danger at a more desperate rate in order to protect itself.
Logic using the traits of nature in general, one must persume it is #2. Unless the complete theme of nature has been put completely to the wayside here, then & only then, #1 might have merit.
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