Folks:
I just posted a 25 second mp3 stereo file on my site which depicts a group
of longhorn beetle larvae (Cerambycids) chewing away at the inner bark of a
log, recorded on 6/5/01 in the Appalachicola National Forest SW of
Tallahassee, Florida, in typical pine woods. Cricket frogs are calling in
the background and crickets are trilling nearby.
The address of the soundfile, which I call "The Big Chew", is:
www.naturesound.com/mp3s/chew.mp3
The two loudest individuals seem to alternate their chews, but I don't
believe this is deliberate. They were about 5' apart on the log.
I could hear these insects chewing about 150' away, in site of all the othe=
r
sound in the forest.
Lang
> Folks:
>
> Thanks for all the interest in wood-borne and ground-born sounds. My rea=
l
> purpose is to stimulate investigations in many areas of our curiosity, ev=
en
> as you all do for me every day.
>
> But, I regret the tone of my brief note of yesterday. Still, it has been
> my long experience on the internet that outrageous statements often flush
> out facts much more quickly then polite queries do - a summary of five
> years of answering BirdChat questions and then never getting any answer
> whatever to those questions that I pose. I still apologize. Even making
> the comparison between this group and BirdChat is, perhaps, invidious! M=
y
> thanks especially to Rich for looking into the whole ideas and
> implications, and to Jim for the referral to Rex Cocroft's work.
>
> My interest in the 60's of sounds within trees was far more biological. =
If
> burrowing insects, such as the larger Buprestid and Cerambycid adults can
> tunnel a cylindrical straight hole through healthy hardwood for 30 cm,
> there MUST be some noises associated with this. I have heard and recorded
> ID? beetles making loud noises audible from 20 ft from freshly cut White
> Pine logs as they drop their powdery sawdust alongside the logs. The
> families of Bostrichidae, Lyctidae and Anobiidae (death-watch) beetles a=
re
> even more famous for gnawing audibly, or doing something that alerts
> air-borne sound detectors like us.
>
> It seemed to me that if we humans could hear their gnawing, some animal
> predators (woodpeckers, for starters) might hear or sense the vibrations
> as a location aid. So I was really listening for tunneling sounds, and
> never heard even one. What I really wanted was to record some intermitta=
nt
> gnawing, then have a Downy Woodpecker land on the tree, and work its way =
up
> one side, and have the gnawing sounds stop for a while. That was my fanta=
sy.
>
> In the course of a year, I heard and recorded many other sounds I had not
> even suspected: tiny birds landing fifty feet from the sensor; dogs walki=
ng
> across an exposed root thirty feet from the trunk; flying squirrels racin=
g
> about on the bark, at a deafening level. This racing one night was sudden=
ly
> interrupted by a Barred Owl hitting the bark with great force (a miss!),
> followed by the squirrels (there were two on the tree at that point)
> spiralling upward to swoop across the valley to another tree. Pretty
> dramatic stuff, a lot at night. For ten years, every time I talked to a
> bioacoustics friend (Roger, Katey Payne, Chris Clarke, etc.) I tried to g=
et
> them interested in taking on this simple project, or at least to sic a
> clueless grad student on it. No takers. Everyone wanted me to do it, an=
d
> I didn't.
>
> RE Thorn-bugs love songs - I am not sure where the leg-pulling begins and
> ends, here, WRT Rex and his one-of-a-kind rumbling ten foot bugs. So I'l=
l
> leave it alone for a while. (Sorry, Lang, for misspelling your
> name!). Love calling was one aspect that I didn't expect to be lucky
> enough to stumble onto.
>
> I have wondered for three decades whether the silence from gnawing heard
> day and night was:
> 1. because I didn't have the sensors on the right trees - maybe only the
> ones I listened to were gnaw-free.
> 2. because the gnawing beetles do so very, very quietly; perhaps the
> evolution of sound makers and their sound-chasing predators has evolved t=
o
> a point of mostly silence; or maybe they are so well protected in the
> wooden tunnels they could (evolutionarily) care less; or
> 3. because (you name it).
>
> My wife and I did put a chart recorder on one tree at a neighbor's place,
> one with a flying squirrel feeder on it, and found out
> a lot about nocturnal feeder-related Glaucomys behavior.
>
> I will tell you one low-tech fact that emerged. The sound velocity in
> solid northern hardwoods, such as oak, hickory, ash and maple varies with
> direction: radially, longitudinally and tangentially, and that the veloci=
ty
> in brass is right within that range. This means (historical music
> instrument and furniture fans) that brass screws holding thin wood togeth=
er
> will not make reflections or refraction nodes, of themselves. No sudden
> impedance shifts. Very interesting. Now a joint itself, another question=
,
> as is the velocity in horse-hide glue (?). Instrument makers have
> long-known one fact that my xylophonics confirmed: for the lossless
> movement of vibrations, wood is nearly as coherent a material as you migh=
t
> find.
>
>
> my very best,
>
> Marty Michener
> MIST Software Associates
> 75 Hannah Drive, Hollis, NH 03049
>
> coming soon : EnjoyBirds bird identification software.
>
>
>
>
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