Tanya Lewis, LiveScience Staff Writer
Date: 11 February 2013 Time: 07:52 AM ET
If optimists see the world through rose-colored
lenses, some birds see it through ultraviolet ones. Avians have evolved
ultraviolet vision quite a few times in history, a new study finds.
Birds depend on their color vision for selecting
mates, hunting or foraging for food, and spotting predators. Until recently,
ultraviolet vision was thought to have arisen as a one-time development in
birds. But a new DNA analysis of 40 bird species, reported Feb. 11 in the
journal BMC Evolutionary Biology, shows the shift between violet (shorter
wavelengths on the electromagnetic spectrum) and ultraviolet vision has
occurred at least 14 times.
"Birds see color in a different way from
humans," study co-author Anders Ödeen, an animal ecologist at Uppsala
University in Sweden, told LiveScience. Human
eyes have three different color receptors, or cones, that are
sensitive to light of different wavelengths and mix together to reveal all the
colors we see. Birds, by contrast, have four cones, so "they see
potentially more colors
than humans do," Ödeen said.
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