If it hadn’t been cecil that said it, i’d never have believed the shrimp/pink flamingo connection. Because I learned in biology that bird’s feathers were much like hair or fur and even colored with the same pigment - melanin (I think). IIRC, melanin creates different colors in feathers by being arranged in such a way that it refracts light like a prism, giving the appearance of - say red or yellow - when light is bounced off of it.
(Experimentation on my own parrot bears that out. If you look at one of her bright green feathers by lighting it from behind so that the light shines through it (rather than being reflected off it) you find that the feather is “really” brown. Like my hair.)
So somehow in flamingos (and I guess canaries) a pigment other than melanin can get into the feather and change it’s color. Which finally leads me to my question - will this work with my own hair? If I eat the same shrimp can I turn my hair pink? Will too many carrots turn my hair orange? Is that how we get redheads?
I’ve never heard of hair turning orange from carotene. In another thread, Colibri said
Nope. They have red hair because they have red melanin instead of–or in addition to–brown melanin. The genetic difference between the two forms of melanin is slight.
I have no clue about the shimp= pink hair thing, but I do know for a fact that eating too many carrots can lead to an orange-ing of the hands. It happened to a good friend of mine as a child. He ate one of those 1/2 lb bags and got really sick. A while later his palms and parts of his fingers turned orange.
Pigments in bird feathers are generally either melanins (which mostly produce browns and blacks) and caroteniods (which produce yellow/orange/red). Blues are mostly produced structurally and not by pigments, that is they result from optical effects at the surface of the feather (see Cecil’s column Are Blue Jays not really blue?). Green is usually produced by the combination of a yellow pigment plus a blue structural color. The Turacos, an African family, are unusual in having several unique pigments, including ones for red and green.
Note that the foods that the flamingos eat - small shrimp and blue-green “algae” (cyanobacteria) - are not themselves pink. They merely contain carotenoids that the flamingo converts to a pigment called canthaxanthin, which is then deposited in the feathers.
As for how we get redheads, biblophage has it right - in humans the color is produced by a melanin, not a by a carotenoid. In order to get pink hair by eating shrimp, you would have to have some metabolic mechanism to convert a carotenoid to a pink form, and then deposit it in the hair - which humans don’t have.
Now, Jill, you’re perfectly entitled to gloat, having beaten me at my own game. (And there should have been a after my post).
To elaborate, Jill challenged my speculation that the red color in macaws is due to carotenoids. In fact, macaws apparently do have a unique non-carotenoid pigment called psittacin not found in other birds.
Originally sent to me by Jill:
**
First bet I ever paid off in poison frogs. (I hope the last, too.)
I remember reading a case study published in a popular magazine years and years ago, where the wife brought her husband in because his skin was slowly turning redder and redder. His overall health was good with no blood pressure problems or overexposure to sun. The clue came when the doctor investigated the man’s diet. The patient was consuming large amounts of tomato juice with meals and between meals. Somehow the pigments of the tomatoes were building up in his skin. The effect appeared to be all over his body and not just his face or hands.
I visited Hilo, Hawaii’s botanical gardens a few years ago, whehe I saw some white flamingos. I asked about them and was told they ate a sort of (for want of a better term) “Flamingo Chow” It didn’t have the shrimp they need to be pink.
They aren’t there anymore. Could the diet have caused their exit?
after my post).