Robbins sent me the above Word doc along with the following text:
Attached is a document that was produced the day before the Sibley et al. article came out. It was sent to a number of people on 17 March 2006, including the IBW Recovery team leader….he denied our request to share it with the rest of the recovery team. You can share this with whomever.
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7 comments:
Hmmmm....a very troubling letter...a very troubling letter indeed!
I thought we had already heard most of this? It sounds familiar; I even believe I probably read it here?
If the ARU sounds are from playbacks of the Tanner recordings they should match exactly in timing and spacing of the individual kents and in fundamental pitch. However, they don't.
That said, I already stated my personal feeling that audio data should be secondary, with indisputable visual/photo/video contact being the primary evidence. Audio tells you to go look and see what the source of those sounds really is.
The problem, Bill, is that people who use tapes and ipods, now, often just record 1 kent, go out into the field and play it a few times on repeat.
Actions like that. Also like many people you don't quite understand how pitch (frequency) is exponentially attenuated over distance. You have to know how close the calling object is to your recorder to make pitch judgements of the original sound.
May I suggest a good signal processing book, maybe "Filtering in the Time and Frequency Domains" by Blinchikoff and Zverev?
If you need other suggestion, let me know.
Other than all of that. Hey, you're right on. I encourage you to keep trying.
Actions like that. Also like many people you don't quite understand how pitch (frequency) is exponentially attenuated over distance. You have to know how close the calling object is to your recorder to make pitch judgements of the original sound.
May I suggest a good signal processing book, maybe "Filtering in the Time and Frequency Domains" by Blinchikoff and Zverev?
So what does that say about the differences in frequencies between Auburn and the Allen recordings mentioned in the comments of another post? Just wondering.
It means that these Ornithologists need some good cross polination with some good signal processing scientists.
They are comparing distant sounds with up close recordings made by Tanner, et al. Very iffy without knowing what you are doing.
In fact, they could have had a nice paper on that.
They are comparing distant sounds with up close recordings made by Tanner, et al. Very iffy without knowing what you are doing.
Let me rephrase my question: given your knowledge of signal processing and other acoutic matters, what effect does distance have on sounds, and how does that relate to Auburn's results? Should "real" IBWO calls being a lower frequency when recorded at a distance compared to Allen's recordings?
Three names: Allen, Kellogg, and Tanner. Just get CLOSE to that level of evidence. Good Lord people, get a clue!!
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