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Why a Gorget Glitters Transcript-631
BirdNote®
Why a Hummingbird’s Gorget Glitters
Written by Bob Sundstrom
This is BirdNote!
[Call of male Ruby-throated Hummingbird]
When a perched male Ruby-throated Hummingbird raises its head toward the sun at just the right angle, its throat glitters like a crimson spotlight. When it turns its head slightly, the bird’s throat no longer gleams. It appears colorless, dark.
A hummingbird’s brilliant throat feathers are called its “gorget” (pronounced GOR-jit). The term comes from days of old, when a knight-in-armor wore a metallic collar — or gorget — to protect his throat. The hummingbird’s intense glint is the result of iridescence, rather than colored pigments. The bird’s throat-feathers contain minutely thin, film-like layers of “platelets,” set like tiles in a mosaic against a darker background. Light waves reflect and refract off the mosaic, creating color in the manner of sun glinting off a film of oil on water.
[Song of male Anna’s Hummingbird]
Listen to this male Anna’s Hummingbird, putting his glitter to work:
[Tail sound “chirp”]
There he goes! Diving in display toward the female. [Tail sound “chirp”] He plunges downward almost vertically, achieving tremendous speed. [Tail sound “chirp”] Then, he levels off and heads straight into the sun, which makes his gorget glow with iridescent brilliance. (1)
Like a tiny knight in shining armor.
[Song of male Anna’s Hummingbird]
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Hummingbird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Anna’s Hummingbird recorded by T.G. Sander. Ruby-throated Hummingbird recorded by R.S. Little.
Anna’s Hummingbird display “chirp” recorded by C. Clark and A. Varma, U.C. Berkeley
Ambient track recorded by Kessler Productions.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2010 Tune In to Nature.org March 2010
ID# old: 032706gorgetKPLU hummingbird-03b
Paraphrased from: Skutch, Alexander F. and Arthur B. Singer. The Life of the Hummingbird. Crown Publishers: New York, 1973. (Skutch and Singer 1973:64-65)
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