Speaking of loud sounds emitted by hummingbirds, last summer we heard a
noise we hadn't heard before - it was like someone hitting a brake drum with
a wooden mallet (I wouldn't call it a bark - it rang). Really loud. Way
louder than any of the other normal yard birds except maybe flickers or
jays. We couldn't place it, but it seemed to be coming from somewhere near
the house. A few days later I heard the same noise and this time looked out
of the window and was able to identify the source. An Anna's HB was sitting
in the tree nearby and when the noise occurred the little bird's head slewed
rapidly from left to right. Repeat. Clearly it was the HB making this huge
noise.

Now, I'm thinking, was it really coming from the bird I saw, or was it just
watching another that was displaying and making the noise? Well, the first
time we had heard it, I realized, it had been coming from the fuschia
hanging near the back door. So it was a stationary bird. No feather noises
involved...

Some syrinx!


Pat Little
Seattle, WA
mailto:redtail at cablespeed.com


-----Original Message-----
From: tweeters-bounces at mailman1.u.washington.edu
[mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Mike
Patterson
Sent: Thursday, February 16, 2006 4:21 PM
To: Tweeters
Subject: [Tweeters] Re: Shocking discovery

The "dive noise" as it is referred to in the literature is one
of the many, as yet unsolved, mysteries of the hummingbird world.

My assumption when I first hear it was that it was a non-vocal
noise, like the zubbing in the Rufous Hummingbird dive. But the
jury is apparently still out on the subject....

According the BNA account:
"The Dive Noise ( Fig. 2C) is produced by males at the bottom of
their dive in a dynamic display; there is spectrographic evidence
that the sound is "mostly, if not entirely, vocal in origin"
(Baptista and Matsui 1979). Stiles (1982) disagreed with the
interpretation, stating the noise is too loud in relation to the
size of the syrinx and air-sac system to be vocal."

Baptista and Matsui
http://elibrary.unm.edu/sora/Condor/files/issues/v081n01/p0087-p0089.pdf

Stiles
http://elibrary.unm.edu/sora/Condor/files/issues/v084n02/p0208-p0225.pdf

--
Mike Patterson
Astoria, OR
celata at pacifier.com

SNOWY OWLS on the Lower Columbia - links to current information
on the 2005 irruption event:
http://home.pacifier.com/~neawanna/SNOW/SNOW20051120.html
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