Monday, June 04, 2007

More from Collinson


Note that Collinson's observation on flap rate is similar to mine here:
For another thing, Cornell has a single data point for the wingbeat frequency of a fleeing Ivory-bill, and that claim may also be bogus.

The 1935 wingbeats (analyzed by Cornell here) may not be the wingbeats of a fleeing Ivory-bill. The recorded sounds may have been made by an agitated Ivory-bill fluttering near the nest hole.

Listen to the wingbeats here (WAV format). Why do the wingbeats stop abruptly? Note that the eighth wingbeat is still fairly loud, and although the recording continues, no further wingbeats are heard. If the bird was really fleeing, why don't we hear (and why doesn't the spectrogram show) wingbeats 9, 10, etc?


Anonymous said...

Now that's some good stuff.

Anonymous said...

Collinson says:

"I was reading Hill's 'Ivorybill Hunters' and enjoying it very much, from a birding perspective - can't fault the effort. Can't help but like the folks involved either."

But the "What am I doing today"" graphic to the right of his post says today he is "dripping with sarcasm" so it is not clear what he is really thinking.

But even if he is not displaying some British sarcasm I know how he feels about Hillcrow. Among the panhandlers I see on the way to work is a guy who occasionally has a sign that says "Need money for beer!". I always think that you can't fault his effort and he appears to be so shameless that he is probably a likable guy.

Anonymous said...

While I'm here... I said don't get me started, but now I've started... look at the now-infamous wingbeats at 1.6-2.6 seconds. There is NO WAY that bird is tanking away from the microphone like the Luneau video bird. Think of the ground it would be covering - the flaps would fade away to nothing, but instead what there is here is 9 flaps of relatively equal amplitude, that stop suddenly. I think it's very likely that this bird was just fluttering its wings, or at the most going between 2 branches in a tree. Not comparable to Pileateds or IBWOs in level flight Apples and oranges :-O

I've never heard the audio that this shaky (at best) claim was based upon, but IF what Collinson says is true, we can draw two conclusions:

1) He has just completely and utterly destroyed the flap rate theory.

2) This point is so basic that it is shameful that the staff of CLO missed it or ignored it. They should recant any statement on flap rate immediately.

Anonymous said...

Hey, wait a minute. Is this the same Collinson that thinks the CLO and Hillcrow sightings might be legitimate? The same one that thinks Cyberthrush is balanced in his view of the evidence? The same one that was a gutless wonder a while back? The one that wants to cover his ass in case and IBWO shows up?

It is? Ok, that's what I thought.

Anonymous said...

Collinson is a johny-come-lately who still can't decide what he believes.