Joel Kontinen
Why are songbirds so colorful?
Hidden layers of colour in the plumage of tanagers and
some other songbirds explain what makes them so eye-catching.
Brightly coloured songbirds called tanagers are so
eye-catching because they have a hidden layer of black or white beneath their
dazzling plumage.
Painters often prime a canvas with a layer of white to
enhance the colours they will eventually layer on, as well as to make it
smoother and stronger. But it seems this is a mechanism that birds were using
long before humans picked up paintbrushes.
Rosalyn Price-Waldman at
Princeton University and her colleagues have found that when songbirds in the
tanager genus Tangara have bright red or yellow plumage, they usually
have white layers hidden underneath. When they have blue plumage, they have
black layers beneath.
To investigate why, they removed 72 feathers from
taxidermied tanager specimens in the Natural History Museum of Los Angeles
County’s collection.
By taking pictures of the feathers on different
backgrounds, the team measured how their reflectance or absorption of light
changed, finding that the underlayers make the top layers look more colourful.
Source:
Chris Simms 2025 The secret to what makes colours pop on dazzling songbirds | New Scientist 23 July
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