I am a university student studying the pigmentation of bird feathers, and I had a question about the turacin found in touraco feathers. I understand that turacin is a water soluble pigment, and I wondered how touracos maintain their red coloring in the wild. Has much research been done on this? Can anyone help me with this question?
Return to Bird Taxidermy Category Menu
The turacin your speaking of is located in the primary feathers of the bird only (as far as I know). Like most other birds, the tauraco preens itself and "water-proofs" it's feathers with the oil produced in the gland at the base of the tail. The birds I've mounted didn't lose too much color from just being damp or wet, but mostly when they were washed in soapy water or let soak for some time. In the wild my best guess is that because the wings are folded most of the time, the primaries are protected from the elements - even during a rain. All of this is conjecture on my part and you would do well to contact someone who has them in captivity.
I just found some really interesting information about the pigments in a book I have : Handbook of the Birds of the World Vol. 4. Tauracos actually have 2 and maybe 3 pigments! Of the 23 species, most have one or more of these pigments. It was too long to re-write here, but the book is easy to find and although it did say that only alkali's will remove the Green pigmentation, it didn't really answer the questions you have about how they maintain it in the wild - at least not the small part I read. Good luck on your quest!
Turacos are the only birds in birdom that actually produce a green pigment. Other green pigment found in the remainder of the bird species is a combination of blue and yellow pigments and not the true green of the turaco's feathers. The red pigment they produce, called turacin is a complex molecule that has around 7% copper in it's base. It most resembles hemoblobin in structure, which also has a 7% copper component. The green pigment (called turacoverdin) and the red (turacin) are both water soluable, although they dissolve best in alkaline conditions. The pigments are extracted and used as coloring by some forest dwelling tribesmen.
The turacos are thought to extract the base pigment material from the fruit they eat and convert it into the two pigments unique to the species.
Why doesn't it wash off in the rain: There are four reasons for that not happening. A: Rain water is not usually alkaline. B: The pigment is buried deep in the cellular structure of the feather and not worn as if it were an applied dyestuff. C: While the green (turacoverdin) feathers are largely contour feathers and cannot be tucked away and shielded, in part, from the rain, most wild birds seek some shelter during monsoon rains - even if it is just a canopy of leaves. D: Like Patrick said, birds have an oil gland at the base of the tail which produces a lanolin substance that is used to preen and oil the feathers to protect them from moisture. The oil film repels water in most instances.
Neither turacin nor turacoverdin bleed out of the feathers like color from a cheap shirt when they are immersed in water. Any bio-science student can tell you that the leaching process takes several days and doesn't occur on contact. Science thought about the subject is that the bird's diet constantly provides a supply of components to make additional pigment on an ongoing basis.
If the pH of your soap/detergent solution is in the higher range above 9-10 or so, the color will instantly bleed out. It makes a beautiful color in the water as the color is leached out.
I guess that leaves Tide out of the loop....LOL