Ivory-billed Woodpecker (formerly updates) (4 Viewers)

fangsheath · Sep 30, 2006

When I say mechanical, I mean that the sound seems squeaky or whiny but not nasal, and in many cases it fades in and out in a rather random way, not having a sharp beginning and end as is typical of known ivory-bill sounds. See for example the 2 putative kents recorded on 4/11 at 8:56. To me the sound is reminiscient of a swingset or rusty hinge squeak. Without knowing the physical relationships of the recorders to the environment it is difficult to know what can be ruled out. Judging from Appendix 1, many if not all of these kinds of kents were recorded at one station and not at others. This would seem to rule out very distant sounds, but 500 m is pretty wide spacing but it is possible that this recorder was positioned in such a way that it picked up rather distant sounds from a particular direction that the others didn't.

I think a CLO-type analysis of the sounds would be very interesting. Charif has never been explicit about the criteria he has used for accepting or rejecting sounds. One wonders how many lone kent-type sounds, similar to those recorded in Florida, were recorded in Ark. It would also be quite interesting to run the Florida putative kents through his Random Forests program.

I don't remember what format the ARU's use, it may be a propietary format. Even the ARU recordings on the CLO website are not readily downloadable as are the ones posted by Dr. Mennill.

Jesse Gilsdorf · Sep 30, 2006

emupilot said:
Nice analysis, fangsheath. Since we have a very limited sample of known IBWO recordings to work from, it's pretty hard to guess how much natural variability should be expected in kents and internal knock spacing. Are John Dennis' putative IBWO kent recordings available? How much variation in internal knock spacing (and "kent" frequencies if applicable) is there in other Campephilus species, like Pale-billed?

It's not necessarily surprising that double-knocks drop off after mid-March while kents don't, since the former is a territorial call and the latter would be communication between individuals. Again, lack of confirmed IBWO recordings would require us to use another Campephilus to guess as to whether this should be expected.

Yes Fang did his usual frighteningly good analysis. Good Job!!! Obviously you went to one of the few colleges that still teach students how to think as opposed to what to think.

Emu:

How do we know that double knocks are territorial and kents communications? Is this derived from other campephiles in general or some source?

If territorial, wouldn't it be more likely then that the males would be the only ones making double raps then -- marking out a territory?

Thanks for any illumination on that.

Jesse

Edward woodwood · Sep 30, 2006

MMinNY said:
Go ahead. Spend four winter months sleeping on the ground in North Florida, as Brian Rolek did.
I'd still like to know about the audio.

I agree, it's enough to drive anyone barking.

Mind you, he did see one within an hour of arriving (after picking the location off Satellite maps...)

not really a birder, is he?

The audio - it's bollocks Mark. Never mind it

Tim

MMinNY · Sep 30, 2006

I hear what you are describing. Would the recording format and/or quality of the equipment be a factor and how would either impact spectrographic analysis?

fangsheath said:
When I say mechanical, I mean that the sound seems squeaky or whiny but not nasal, and in many cases it fades in and out in a rather random way, not having a sharp beginning and end as is typical of known ivory-bill sounds. See for example the 2 putative kents recorded on 4/11 at 8:56. To me the sound is reminiscient of a swingset or rusty hinge squeak. Without knowing the physical relationships of the recorders to the environment it is difficult to know what can be ruled out. Judging from Appendix 1, many if not all of these kinds of kents were recorded at one station and not at others. This would seem to rule out very distant sounds, but 500 m is pretty wide spacing but it is possible that this recorder was positioned in such a way that it picked up rather distant sounds from a particular direction that the others didn't.

I think a CLO-type analysis of the sounds would be very interesting. Charif has never been explicit about the criteria he has used for accepting or rejecting sounds. One wonders how many lone kent-type sounds, similar to those recorded in Florida, were recorded in Ark. It would also be quite interesting to run the Florida putative kents through his Random Forests program.

I don't remember what format the ARU's use, it may be a propietary format. Even the ARU recordings on the CLO website are not readily downloadable as are the ones posted by Dr. Mennill.

Jesse Gilsdorf · Sep 30, 2006

By the way -- where is the recovery plan? Today is the 30th, and I haven't found it.

MMinNY · Sep 30, 2006

Tanner suggested that double raps were also used as alarm calls or when a mate was away, presumably as location device. (p 62.).

Jesse Gilsdorf said:
Yes Fang did his usual frighteningly good analysis. Good Job!!! Obviously you went to one of the few colleges that still teach students how to think as opposed to what to think.

Emu:

How do we know that double knocks are territorial and kents communications? Is this derived from other campephiles in general or some source?

If territorial, wouldn't it be more likely then that the males would be the only ones making double raps then -- marking out a territory?

Thanks for any illumination on that.

Jesse

fangsheath · Sep 30, 2006

MMinNY said:
I hear what you are describing. Would the recording format and/or quality of the equipment be a factor and how would either impact spectrographic analysis?

The recording format should not have a great impact in the spectral analysis. The characteristics of the device may have some impact, but in my experience most modern devices have more than enough sound quality to produce decent spectra. Even the old Singer Tract recordings produce good spectra (there are not just ivory-bill sounds on them) that are readily compared to the results from the ARU's. Some of the putative kents from Florida were recorded with camcorders; even my digital still camera has an excellent mic and the movie mode has enough temporal resolution to produce good spectra.

naples · Sep 30, 2006

Does anyone know if there is a way to determine which log snag will be scaled next or most likely to be scaled? It seems retro-active to focus on snags that have already been scaled; if your sole focus is on the killer video.

Keep in mind that, the best and longest views in the past 40 years were of feeding birds.

fangsheath · Sep 30, 2006

I think scoping for stressed or dying trees that show little or no evidence of scaling or excavation is the way to go. The best time to do this is in the warm season, when it is much more apparent from the appearance of the leaves which trees these are.

I see no evidence of the Draft Recovery Plan. It may be in the process of being distributed, I would not necessarily expect it to be posted on the web site right away.

MMinNY · Sep 30, 2006

Thanks Fang. . .Of course, these things do make a difference to the naked ear, but there seems to be a pretty big range in the recordings on the site. I haven't listened to them all, but some sound a lot like the Tanner calls to me, while others do not.

One key factor is the extremely limited information we have about IBWO calls -- leave aside the question of behavioral differences between regional populations. It will be very interesting to see how this all develops.

fangsheath said:
The recording format should not have a great impact in the spectral analysis. The characteristics of the device may have some impact, but in my experience most modern devices have more than enough sound quality to produce decent spectra. Even the old Singer Tract recordings produce good spectra (there are not just ivory-bill sounds on them) that are readily compared to the results from the ARU's. Some of the putative kents from Florida were recorded with camcorders; even my digital still camera has an excellent mic and the movie mode has enough temporal resolution to produce good spectra.

naples · Sep 30, 2006

Some of the new scaling evidence suggests to me that the animal in question knows precisely where to strip the bark. I know it’s probably the $64,000 question, is this accomplished with luck, diligence, sight, sound, or hearing?

fangsheath · Sep 30, 2006

naples said:
Some of the new scaling evidence suggests to me that the animal in question knows precisely where to strip the bark. I know it’s probably the $64,000 question, is this accomplished with luck, diligence, sight, sound, or hearing?

Behavioral evidence suggests that woodpeckers use hearing to detect insects they cannot see. One interesting thing about the Florida foraging sign is that in many cases the birds seem to be focusing on deep borers, not bark beetles. I will have more to say about the foraging sign evidence later.

MMinNY · Sep 30, 2006

In the interview, Hill speculates that it's sound, but your insight is dead on. Again, have a look at Mike's photos on the other thread, and you'll see the same thing.

naples said:
Some of the new scaling evidence suggests to me that the animal in question knows precisely where to strip the bark. I know it’s probably the $64,000 question, is this accomplished with luck, diligence, sight, sound, or hearing?

naples · Sep 30, 2006

MMinNY said:
In the interview, Hill speculates that it's sound, but your insight is dead on. Again, have a look at Mike's photos on the other thread, and you'll see the same thing.

Stethoscope dead and dying trees?

Edward woodwood · Sep 30, 2006

It has long been suspected that woodpeckers may locate food by auditory signals, following initial 'give away' visual signals. Some MAY use auditory signals more frequently or singly but this is hard to prove experimentally

no great insights there...

Tim

Jesse Gilsdorf · Sep 30, 2006

You may not have to stethoscope. Depending on the beetles, and the number of them, you may be able to hear them yourself. I believe that the birds hear the beetles, which means that they have extraordinary hearing ability (a problem for us if we are not quiet), and then they start digging.

The reason that a tree may be scaled intensely is that a bird this big is going to eat more beetles than say a downy. The work involved in scaling is clearly something that requires a lot of energy. No animal is going to waste more energy than it gains by eating the prey. Not normally done.

The reason for the big scalings is that the bird is hitting trees that have clearly a large infestation in it. It is not going after one beetle but numerous. The bark peelings have been described for a long time, as has the "cross hatching of a screwdriver" both of which I clearly I am finding. Could there be another method? Sure. The bird is going to eat, and if it doesn't find a jackpot of beetles it may eat less. Plus the variety of foods will vary with the locations, years, seasons, etc. If there is one beetle it is not going to take down half a tree to get to it. In fact, if there is one beetle the damage seen may appear similar to smaller woodpeckers who would go after the same prey.

Scalings may be different in one year than the next, in one season than the next. It may really depend on who is for dinner, and how plentiful they are in a given year or season.

I still expect to see large scalings for this bird. Others may not.

timeshadowed · Sep 30, 2006

Tim Allwood said:
If i saw an IBWO in the field, I'd be writing a . . .book of fieldnotes instantly. Tim

Then why not teach the U.S. Birders "How to" take field notes?

Why don't you write up a down-loadable/printable worksheet?

Edward woodwood · Sep 30, 2006

has it come to that?

paaaaaaaaaathetic!

Tim

PS, get a child's birding book - it'll tell you how to take notes in there

Tranquility Base · Sep 30, 2006

Leave it Tim: ain't worth it! OR!!!!! I'll hold your coat and phone!

Xenospiza · Sep 30, 2006

A useful thread about field notes:
http://birdforum.net/showthread.php?t=68019

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