I’m getting a little scholarly as of date reading all these manuals that my biologist-friend from UP has sent to me through e-mail, when she learned that I was into breeding zebra finches. I don’t profess to understand everything I’ve read, but this one scientific study caught my attention because I instinctively cannot figure out how to make the colors of my male zebras stand-out by giving them the proper food. We all know that the male is more “colorful” in a sense compared to the female, and this study has proven that the male actually gets more carotenoids/pigments in their food intake. The start of the paper reads like this:
Here, we studied within- and between-sex patterns of food intake and plasma pigment circulation in the Zebra Finch (Taeniopygia guttata) to assess how sexually dichromatic, carotenoid-based bill pigmentation serves as an indicator of pigment access in the diet and carotenoid transport through the bloodstream. First, in a food-choice study, we found that males and females did not consume different types or amounts of food, despite dramatic sex differences in bill coloration. Similarly, variability in carotenoid-based bill pigmentation within each sex was uncoupled from levels of food consumption. Next, we used high-performance liquid-chromatography (HPLC) to quantify the types and amounts of carotenoids circulating through blood. Male and female Zebra Finches circulated the same four major carotenoid pigments in blood plasma (lutein, zeaxanthin, anhydrolutein, and cryptoxanthin), but males circulated a significantlyhigher concentration of plasma carotenoids than did females. Within both sexes, individuals thatcirculated more carotenoid pigments displayed more brightly colored bills. In sum, these resultssuggest that physiological factors such as pigment transport may play a more important role inshaping variability in carotenoid-based bill coloration in this species than does diet. Future studiesshould be aimed at identifying the proximate determinants of plasma carotenoid circulationin these birds as well as how circulated pigments are used to produce maximum color displays.
You may download the research article here. I am thinking we can apply the same concept to our gouldians and canaries.
6 users commented in " How Food Intake Affects the Pigmentation of Our Dear Zebras "
Follow-up comment rss or Leave a TrackbackI feed my birds this commercially available 8 in 1 seed mix product that’s supposed to help brighten the bird’s feathers or something. I don’t know if it’s helping or not but the seed mix is different from one that is for Nestlings. I think the manufacturer already made a study on the nutritional content of different seeds and that’s how they know. There is also a seed mix for conditioning, and for song development.
I’m not surprised by the findings and for the same reason you give red-factor canaries carotinoid rich food colouring in their water at moulting. The colour is incorporated into the new feathers then and it’s fixed. Feeding at other times won’t make any difference. There are foods that are needed only sometimes such as when young are in the nest or eggs are likely to be laid the food should include a higher protein content. My birds personally hate boiled egg. I only recently introduced this and it’s going to take them a long time to get used to this as a supplement. Because of food preferences some supplements have to be introduced long before they are actually needed or you may miss the window of opportunity. As for Gouldians they probably would benefit from colouring supplements but only to a point. The red face for instance occurs because the birds convert yellow plant derived pigment into red carotinoids, the yellow-faced type lack the capacity top do this conversion and so the feathers express the yellow pigment in the diet. I don’t know if the experiment has been done but it’s a reasonable hypothesis to suppose that if you over supply a red colouring to a yellow faced Gouldian (as you do for red factor canaries) you might end up with a red faced one.
nice info there on the canary, greg.( i.e. the red-factors or any colored bird for that matter only need the pigment during moulting, after which any “colored” food you might give them will not make a difference.) i’ll try to remember that one.
hey, who has joined bird(finch) shows? does anyone know if a special diet for pigmentation is actually given to birds for them to have sort of a color-advantage over others? just a thought..
This is a very interesting article. Thanks for this one! In the article, it states that there is no relation between diet and the coloration of the finch. In the study, it says that both sexes consumed the same amount of food, but males have higher carotenoid pigments circulating in their blood. The higher circulating pigments in male has nothing to do with their diet. According to the study, male hormones may have played a major role in transportation of more pigments in the bill and feathers of the finches. If you read the discussion part, there is a cited reference wherein a castrated male zebra finch had a duller bill coloration and a female zebra finch which was injected with a male sex hormone had a brighter bill coloration. In this study, it is concluding that more than diet, hormones or other physiological mechanisms are playing a role in the brighter coloration of male zebra finches.
(however, if you are striving to produce a particular color muation, then this is not possible).
My opinion is that if you have a poorly colored finch, no amount of food additive can dramatically change the color of the bird. If you want a nicely colored finch, get one with an excellent lineage, provide the right food, housing and care, then you will have a beautiful specimen. One more thing, making my conclusions from the study, housing your birds in a colony set-up can bring out more vibrant colors to the birds. Male competition for a mate may induce their hormones to kick in and thus transport more pigments to their feathers and bills. The colors may be used by finches to attract a mate. Mas makulay mas pogi.
Like most things, genetics and environment, nature and nurture play a part in the expression of carotinoid pigments. Carotinoids can’t be synthesised denovo in birds or any other animal for that matter and must be taken in as part of the diet. They are in fact structurally related to vitamin A and can’t be eliminated from the diet with out serious consequences. The US National Institute of Health as more information on this at http://dietary-supplements.info.nih.gov/factsheets/vitamina.asp. The expression of where the pigment is expressed on the body is largely under genetic control hence the differences between the male and female coloration and the patterning but at least in humans you can overdose on -carotene and go yellow.
The zebra finch isn’t a particularly colourful bird and its requirement for carotinoid pigment is probably not much more than the maintenance requirement for vitamin A and ordinary seed can supply this without the need for supplements. For other birds the story may be different. The most extreme example is the flamingo – a bird which most people think of as pink, however they are in fact white! In captivity they must be given food colouring during moulting or they turn white as their captive diet usually lacks carotinoids compared to their diet in the wild where the pink colour traces back through the food-chain to algae.
The only mutation where this factor could help is on white zebras, I think it’s because that i’m color blind and I can’t distinguish between an orangy beak and a reddish beak. In short, I’m having lots of problems sexing these whites. There is an 8 in 1 seed mix that’s supposed to enhance the color of finches but I think that works well for gouldians, although I still give it to my zebras. I don’t see any difference it their colors at all.
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