The high whistle of Costa's hummingbird on the western Stokes guide CD
was made by a perched bird.
Kevin Colver
On Thursday, February 2, 2006, at 10:40 AM, oryoki2000 wrote:
>
> The following exercpt from an article entitled "Feathered Gems"
> by the late Luis Baptista suggests that the "ping" or "pop" sound is
> at least partly vocal.
>
> --oryoki
>
> http://www.calacademy.org/calwild/2001fall/stories/hummers.html
>
> "The Costa's hummingbird (Calypte costae) and Anna's hummingbird of
> California have very elaborate dive displays during which whistles
> (Costa's) or loud pops (Anna's) are produced. It was long thought that
> these sounds were produced by the specialized tail feathers, as they
> are in the wing feathers of the broad-tailed.
>
> During spring 1977, my ornithology class and I watched a Costa's
> hummingbird perform its dive display in the Anza Borrego Desert of
> California. At the bottom of its dive we heard a long, drawn-out,
> high-pitched whistling sound. I informed my students that this sound
> was produced with the tail. At this point, the Costa's perched not
> three meters from us, and out of his mouth emanated a shorter version
> of the same high-pitched whistle. He clearly had not read the
> literature; he wasn't supposed to do that! I then compared
> spectrograms of dive-pops of the related Anna's hummingbird and found
> that one of the syllables in the song was almost identical in
> structure to its "dive-pop" sound. Since then, three independent
> observers have reported to me their observations of Anna's
> hummingbirds resting on perches and uttering dive-pop sounds. The dive
> sounds were vocal after all, and not mechanically produced. "
>
>
>
>
>
> "Microphones are not ears,
> Loudspeakers are not birds,
> A listening room is not nature."
> Klas Strandberg
> Yahoo! Groups Links
>
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