Subject: [Tweeters] Re: Anna's tail chip article
Date: Feb 11 12:14:57 2008
From: Pterodroma at aol.com - Pterodroma at aol.com


Fascinating! Mystery solved! Thanks for the link!
There was some discussion on Tweeters about a year ago about this, and as I
recall and even in doing some research, the exact mechanism for the "chirp"
(sounds like a "bark" to my ear) was unknown.

I had been completely baffled by the mysterious "barking" I kept hearing
periodically through the year ...for years, but especially in the spring and
summer but also on warmer days in autumn and even winter. It had a
ventriloquial quality which always sounded like it was coming from ground level amidst
the shrubs and bushes. Even when I cupped my ears to try and pinpoint the
location, it still seemed to be at ground level. I figured it was a small mammal
like a chipmunk (never see those here), Douglas Squirrel (rare), and
eventually decided those barks were perhaps coming from my periodic outbreaks of
those Al Queda minded terrorist aplodontia which can nearly clear cut the whole
yard overnight not to mention the burrowing and moving literally hundreds of
pounds of rocks moved around. I have live trapped, removed, and transplanted
11 to date over the past several years and the insurgency seems contained
and quiet at the moment. (If you don't know what an aplodontia is or what it
looks like, look it up (google). I just can't bring myself to mention it's
common name again because that just seems to confuse most people, even many
life long PNW natives =|:>)}

Then last Spring or early summer when I thought all was well, I started
hearing the "bark" again which seemed to come from about 6-7 feet up and deep in
one of the so far unmolested rhodies. Ah, easy this time I thought. I
looked and looked and looked trying to spot the what should have been not so
little varmint perched up there in the branches somewhere, but all for naught. I
was only inches from it so it seemed, it was ear piercing, and I still
couldn't spot anything or detect any revealing movement even when I rattled the
branches hoping something would fall out or run away. Nothing, except the
"bark" always stopped. This went on for weeks and it was driving me nuts.

Then, last summer came the great epiphany! ...and probably the most
startling unexpected ornithological discovery of my entire life, and yet so simple.
Just by chance when I was puttering about the yard, I just happened to look
up when I spotted a tiny black insect like blur at the same instant I heard
the "bark". After a "what was that?" moment, the sight and sound repeated, and
much to my amazement, it was obviously a hummingbird. Anna's to be precise
and it was going through it's display paces bottoming out over the top of the
rhodie and literally inches above my head when I was probing around in
there. I suddenly felt pretty stupid [as in a total simpleton] having this go on
as such an agonizing mystery for so long, but also enormously relieved. At
least now I knew what it was, but more importantly, what it WASN'T, ...the
dreaded aplodontia.

That led me to do some research about the time the topic concidentally
appeared on Tweeters. It was a mystery and there was no consensus as to the exact
mechanism, just some speculation that maybe it was wing snapping or even an
uttered call note somehow. To me a "bark", a very loud ear piercing, even
somewhat annoying "bark". Annoying I suppose because I thought it was
something else, something much more evil. I mean, how would I have ever guessed a
"bark" so loud and penetrating could ever come from something so tiny as an
Anna's Hummingbird?!? It still seems almost preposterous, but true, and by now
I confess, most welcome as the displaying Anna's Hummingbirds are 'tuning' up
with these recently warming days recently.

One of those feeder regulars is an immature male that I've watched all
winter long going from nondescript drab gray to gradually becoming adorned with
it's regal head and throat gear which is nearly complete now. And with that
along with increased aggressiveness, it's been busy testing, practicing, and
fine tuning itself with the art of great pendulous displays. At first and a
few weeks ago, the "barks" were weak and scarcely audible at all but during
recent days have reached their full intensity although the actual displays are
limited to one or two dives then nothing more for hours which of course will
increase with each passing day approaching Spring.

I am sincerely grateful to Robert & Bernie Meyer for posting the link to
this innovative ground breaking 'thinking outside the box' research which has
led to demystifying the Anna's Hummingbird "chirp" (bark). The nuts and bolts
short answer to the mechanism is this:

-----
"The research settles a long-running debate... The scientists' video
revealed that the sound a male makes coincides with a 60-millisecond flaring of his
tail feathers ? roughly as fast as a blink of an eye. Wind tunnel tests
confirmed the bird's outer tail feathers vibrate like a clarinet's reed, at a
frequency like the highest note on a piano, four octaves above middle C. The
bird's split-second tail spread while diving therefore produces a loud, brief
sound resembling a chirp or a beep."
-----
For the full story which is definitely worth a read, click on this direct
link when online:
_Bird Chirps From Hind End | LiveScience_
(http://www.livescience.com/animals/080201-chirping-tail.html)


Richard Rowlett
Bellevue/Eastgate, WA



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