>Date: Tue, 7 Sep 1999 07:53:21 -0700
>From: "T. Wood/S. Williamson" <otter@PRIMENET.COM>
>Subject: Re: trilling feathers

>Hi, Helen -
>
>PMJI, but I'm intrigued by this phenomenon myself. In adult male Rufous,
>Allen's and Broad-tailed hummingbirds, the outer 2 to 4 primaries are
>modified in shape to create their distinctive trilling sounds. In Rufous
>and Allen's, the outer 4 feathers are sharply pointed with a slight "tooth"
>a few millimeters from the tip; both species make the same metallic whining
>sound in flight. In Broad-tailed, the 2 outer primaries taper sharply
>before broadening slightly, with the outermost feather narrower and more
>evenly tapered than the second. The shaft of each feather is very thin near
>the tip but is actually thicker than normal just before the narrowed area.
>This modification creates the bright silvery trill heard when a male
>Broad-tailed flies by.
>
>Male Black-chinned also make a distinctive whine in flight due to tiny
>notches on the 4 or 5 inner primaries; unlike RUHU, ALHU and BTLH, adult
>females and immature males have less well-developed versions of this
>modification and make a less obvious but still identifiable sound. Oddly
>enough, though Ruby-throated males also have modified inner primaries I
>haven't been able to detect a distinct sound from them in flight (anyone
>else heard something I'm missing?).
>
>A fascinating sidelight: Karen Krebbs of the Arizona-Sonora Desert Museum
>has observed that, at least in Broad-tailed, the sound appears to be
>"optional" depending on circumstances. A new male Broad-tailed introduced
>into the hummingbird aviary immediately stopped trilling, then resumed
>about 2 weeks later, presumably after he had established his place in the
>hierarchy. Examination proved that he had not molted or damaged the
>sound-producing primaries, so he must have been closing off the slots to
>silence himself.
>
>Sheri Williamson
>Southeastern Arizona Bird Observatory
>PO Box 5521, Bisbee, Arizona 85603-5521
>Web Site: http://www.sabo.org
>Business E-mail: sabo@SABO.org
>Personal E-mail: otter@primenet.com
>

================================================

Date: Tue, 4 Sep 2001 19:18:23 +0000
From: "Nancy L. Newfield" <colibri@GS.VERIO.NET>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Wing Sound Debate

I'll start by admitting that I don't have very good hearing and I find it
difficult to put sounds into "words". Descriptions of sounds mean nothing
to me. Nevertheless, I can hear some sounds - if they are loud enough or if
the sound-maker is close enough.

Nearly all of the hummers I have encountered make some kind of sound with
their wings. For some, the sound is only audible at very close range, but
for others the sound carries far. I have heard sounds that I would describe
as "whistles" coming from adult male Broad-taileds, adult male Rufous, and
adult male Allen's.

The wing "whistle" of the adult male Broad-tailed seems very much louder and
more distinctive than the wing "whistles" of the adult males of the other
two species. I can hear it from a distance of 100 feet or more. I have
limited experience with this sound in Louisiana, but have heard it
abundantly out West - recently. The two adult male Broad-taileds that I
have handled in Louisiana have made a more muffled sound and their 10th
primaries were worn, with part of the tip missing.
I can hear the wing "whistles" of the other two species from a distance of
about 25 feet, but I can't pick out Allen's from Rufous. I have no doubt
that others can perform this feat. I have considerable experience with
adult male Rufous in Louisiana and lots of experience out West, but only a
little exposure to adult male Allen's either in Louisiana or out West.

As far as I know, the adult males of these three members of the genus
Selasphorus are the only hummingbirds in North America, north of Mexico,
that have highly modified outer primaries [#10]. Immature males and females
of all ages of these species lack the attenuated shape that produces the
"whistle". I have heard sounds coming from their wings, but I would not
describe those sounds as "whistles". The wing sounds of immature male and
female Broad-tails is louder and more distinctive than the similar wing
sounds emitted by immature male and female members of the other Selasphorus
species.

I have heard wing sounds, but not sounds I would call "whistles", coming
from the wings of adult male Ruby-throat and from adult male Black-chins.
To my ear, these sounds are different from each other. I've always thought
the difference in shape of the 10th primaries between these two members of
the genus Archilochus.

Owing to the various shapes and dimensions of the outer primaries of other
hummer species, there must certainly be considerable differences in the
sounds made when the wings cut through the air. I am sure those with more
acute hearing can identify other hummers by their wing sounds, but I cannot.
I think this debate might hinge on the actual definition of the word
"whistle". Now, can we find a dictionary that will adequately define
"whistle" to the agreement of all. I think not.

NLN

Nancy L. Newfield

=====================================================

Date: Wed, 5 Sep 2001 09:18:46 -0500
From: Lanny Chambers <lanny@HUMMINGBIRDS.NET>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] new arrival/wing whistles

On 9/5/01 8:02, MiriamLDavey athena@INTERSURF.COM wrote:

>Has anyone else besides me heard the VERY faint wing whistle of an adult
>male Calliope?

Yes indeed. As you say, it's faint, and only audible to me when the bird
flies within a few feet of my ears. It's a drier sound than the other
whistles, more clicky/rattly and less sweet. Very distinctive, not at all
like the others.

For me, one of the best parts of the New Mexico conference was hearing
and comparing the differences in wing and vocal sounds among the four
species present. I can't say I've learned them all in only three days,
but the exposure raised my consciousness dramatically.

I suspect much of the disparity in Humnetters' reported observations is a
function of variations in their hearing acuity--women tend to have better
hearing than men, especially in the higher frequencies, and to lose much
less of it as they grow older. It's largely in the higher harmonics that
one species sounds different than the others, the stuff that doesn't make
it through a hearing aid. (One of my other hobbies is high-end audio--I'm
a "beta tester" for an equipment manufacturer--and I've been able to
train my ears to distinguish astonishingly-small differences in sound.)

As was suggested yesterday, folks' hearing varies as much as their
vision, and is less likely to be corrected (or correctable).

Lanny Chambers
St. Louis, USA

===================================================

Date: Wed, 5 Sep 2001 09:24:19 -0700
From: Robert Protz <robertprotz@YAHOO.COM>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Acoustics and Hummer sounds

--- Lanny Chambers <lanny@HUMMINGBIRDS.NET> wrote:

> As was suggested yesterday, folks' hearing varies as
> much as their vision, and is less likely to be
> corrected (or correctable).
>
> Lanny Chambers
===================

AND

Fernando wrote:

Humnetters,
During my hummer research at UC Berkeley many years
ago I made sonograms of the wing trills of spring
adult male Allen hummers, and the sounds came
out as a horizontal series of spikes. I assumed that
counting these spikes against the duration of the
sonogram I could get the wing beat frequency, but the
number came too high -- 150/sec or so. Then I wrote
Greenewalt (who was then still alive) asking his
opinion, and he replied that he did not trust
sonograms and used a device called a "recording
oscillograph" to get his wing beat values. So I still
don¥t know what the spikes mean, but is tempting to
say that each represents half of a wing beat cycle,
the moment the wing starts coming up or down.
Has any of you tried to analyze hummer wing trills
acoustically? Any comments?
Cheers,
Fernando
===================

Dear Humnetters,

OK, it's time for me to put on my Audiologist hat here
and chime in a little bit.

First of all, let me say that Lanny is right on the
button with his comments about human hearing and th e
variability it introduces into this disucssion about
hummer wing sounds. The only thing I would add is
that most of the accelerated high-frequency hearing
deterioration in men is caused by noise exposure.There
really is no such thing as hearing loss due
strictly to aging (presbycusis), it's all due to
damage to the cochlea (inner ear) from trauma due to
noise exposure and other medical conditions, such as
ischemia, etc.

I'm very curious about Fernando's comments that
Greenewalt did not trust sonograms. I can't imagine
why. Sonograms are the de rigeur method of analyzing
human speech.

Now, for those who want to follow along and have no
idea what were talking about here, see:

http://www.voice-center.com/spectrogram.html

A sonogram plots time (horizontal) vs. frequency(vertical)
with intensity shown as a function of the
darkness of the graph (darker = more intense). The
above website shows a great example of a sonogram with
it's accompanying oscillogram right below it. You
can't really get any useful frequency analysis from a
complex audio signal from such an oscillogram. You
would have to do a Fourier analysis of that to derive
the frequencies present, and that is essentially what
the sonogram is.

Now, Fernando, your conclusion about the horizontal
series of spikes on your sonogram indicating frequency
is absolutely correct. But it probably isn't
wing-beat frequency, it's probably feather vibration
frequency! These mechanical wing noises aren't due to
wing-beat rate, but the rate at which the feathers
vibrate due to airflow across them. I see no reason
to discount a value of 150 Hz. This would indicate a
square-wave pattern (and square waves normally sound
like 'clicks') at a rate of 150 times per second. The
audio frequencies making up those clicks (which are
normally extremely complex) would be indicated by the
pattern of the individual spike on the sonogram, how
much ink was deposited at what vertical level,
indicating the variation of intensity by frequency.

Now, where do we go from here? Well, I'd love to see
those sonograms! :)

Rob Protz in W PA

PS: about the above website I noted - one word they
didn't use but should have was 'formant', the
concentration of the acoustic energy of vowel soundsinto discrete bands. If anyone wants to discuss that
further, contact me privately.