A hummingbird's brilliant throat feathers are called a "gorget," a term applied in past centuries to the metallic swatch protecting the throat of a knight-in-armor. Light waves reflect and refract off the throat feathers, creating color in the manner of sun glinting off a film of oil on water. The gorget of this Rufous Hummingbird is stunning!
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: [Song of male Anna’s Hummingbird]
There he goes! Diving in display toward the female. He plunges downward almost vertically, achieving tremendous speed. Then, he levels off and heads straight into the sun, which makes his gorget glow with iridescent brilliance.*
Like a tiny knight in shining armor. [Song of male Anna’s Hummingbird]
You can see a photo of a hummingbird’s gorget at BirdNote.org. I’m Mary McCann.
Hummingbird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Ruby-throated Hummingbird  recorded by R S Little. Anna’s Hummingbird recorded by T.G. Sander.
Anna’s Hummingbird display “chirp” recorded by C. Clark and A. Varma, U.C. Berkeley
Ambient track recorded by Kessler Productions.
BirdNote's theme music was composed and played by Nancy Rumbel and produced by John Kessler.
Producer: John Kessler
Executive Producer: Chris Peterson / Dominic Black
© 2015 Tune In to Nature.org March 2018 Narrator: Mary McCann
ID# old: 032706gorgetKPLU hummingbird-03c
* 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)