what’s red and black and beautiful all over?

There is something special about birds that are red and black that makes them especially beautiful.

A very cooperative male Scarlet Tanager posed low enough in a leafless tree to let us see his striking fiery red and velvety black plumage in Crow Hassan park in Rogers, MN yesterday.

Colors have strong emotional correlates in humans, and we are biologically wired to pay attention to color, because it can convey important information like ripe vs poisonous in fruit. For humans, red can symbolize anger, lust, passion or energy, while black most often symbolizes dark moods, despair, mourning, or death.  Even though they would seem to convey opposing emotions, together they can mean strength or a sense of power.

But what does color mean to a bird — and especially the pattern of red, black, and white?

Bright colors are used to attract mates. Brighter and more contrasting colors are most often an indicator of the health and vigor of that individual and a signal to females that the bird would be a good choice as a mate.  To produce a really red color in their plumage, birds must not only consume great quantities of carotene (yellow-orange pigment) in their diet, but they must turn on an enzyme (about 1000 fold) that converts the yellow pigment to bright red while they are molting new body and wing feathers.

We saw male Painted Redstart warblers in woodland stream communities in Portal, Arizona.

Male Red-bellied Woodpeckers have a lustrous crown of red feathers extending down their necks.

Male Vermillion Flycatchers sport the same red body and black wings as the Scarlet Tanager, but are about half their size. This one was photographed in Tucson, AZ.

Bright flashes of color in males are also useful as threats to other males, warning them not to encroach on their territory or their mates.

Flashing their red epaulets, male Red-winged Blackbirds advertise their territory and threaten other males.

But that still leaves us with the question of why red and black is common among colorful birds in their spring plumage, and there doesn’t seem to be a quick answer to that on Wikipedia.  Keep in mind the colors we see are not necessarily what birds see because they have a variety of color-detecting oil droplets in their eyes that apparently enhance color detection, as well as a greater range of sensitivity to wavelengths of light.  So, it’s a mystery still to be solved.

For more information on the subject, check out this interesting article in Forbes magazine about “how birds became red”.