Most birds possess the ability to see color. But birds can also see in the ultraviolet spectrum. Hummingbirds - like this Violet-crowned Hummingbird - may zero in on certain flowers because their petals strongly reflect in the ultraviolet range. Migrating birds may use ultraviolet light to navigate on overcast days, because the sun's ultraviolet rays pass through the cloud cover.
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Ultraviolet Vision - What Colors Do Birds See?
Written by Bob Sundstrom
This is BirdNote!
[Cry of a Red-tailed Hawk]
We know that hawks and eagles have keen vision, and that owls can see in the dark. [Hoots of a Great Horned Owl]
But what else do we know of the visual ability of birds? Well, most, like us, possess the ability to see color. Yet it also appears that some birds can do humans one better: they can see in the ultraviolet spectrum. Such birds can perceive colors that people can only dream of.
[Begin calls of Budgerigars]
Female “budgies,” the classic pet store parakeets, may choose mates based on how nicely their feathers reflect ultraviolet light. [Wing sounds of Ruby-throated Hummingbird] Hummingbirds likely zero in on certain flowers because their petals strongly reflect in the ultraviolet range. The waxy surfaces of many fruits reflect ultraviolet better than nearby leaves, which helps attract fruit-eating birds like these Scarlet-fronted Parakeets.
[Calls of Scarlet-fronted Parakeets]
[Migrating birds may even use ultraviolet light to navigate on overcast days, because the sun’s ultraviolet rays pass through the cloud cover.]
And it’s not just birds that can out-see humans into the ultraviolet range. Bees, butterflies, bats, and yes, probably even rats, have got one up on us in the ultraviolet world.
See amazing photos of the birds featured on BirdNote at birdnote.org. That’s birdnote.org.
[Aerial display sounds of Rufous Hummingbird]
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Red-tailed Hawk call recorded by L.J. Peyton. Great Horned Owl recorded by W.L. Hershberger. Wing sounds of Ruby-throated Hummingbird recorded by R.S.Little. Scarlet-fronted Parakeet calls recorded by P. Coopmans. Rufous Hummingbird aerial display sounds  G. Keller.
Wild Budgerigar calls recorded in New South Wales, Australia by Martyn Stewart and provided by Naturesound.org
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2014 Tune In to Nature.org April 2014 Narrator: Michael Stein