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I think about this when I see wild turkeys in the area during early spring. The males fan their tail feathers and display their bright colors. From a mate sele

I think about this when I see wild turkeys in the area during early spring. The males fan their tail feathers and display their bright colors. From a mate selection standpoint, the healthy ones have a full set of feathers that are brightly colored. Older and less healthy ones are missing feathers, or the colors are dull. I think what we see in nature is a situation where what began as a selectable trait sometimes carries on evolving, i.e., becoming ever more colorful or pronounced, simply because it was easier to notice and measure, and at the same time, did not become a negative to survivability. If the female is attracted to the intense colors of males, and two perfectly healthy males are standing next to each other, but one is a little more saturated in color, she may select him solely for that reason.

trhway 9y ago
There is a range of studies on various birds showing correlation between higher intensity/contrast of male feather colors and higher testosterone levels. For example: https://www.sciencedaily.com/releases/2008/06/080602121302.htm https://www.sciencedaily.com/releases/2008/06/080602121302.h... or https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3187837/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3187837/ or http://elitetrack.com/blogs-details-2765/ http://elitetrack.com/blogs-details-2765/ "Researchers may have discovered how the bright plumage of male birds evolved as a sign of health and vigor to potential mates. Testosterone, which weakens the immune system, increases the circulation of immunity-enhancing pigments called carotenoids, they find. Healthy birds let the pigment collect in the skin to flaunt their vitality. [/] The bright coloration of some birds is a classic example of an animal advertising its high quality to potential mates. Carotenoids are the pigment in red, orange and yellow skin (and carrots), but they are also powerful antioxidants that boost the immune system. Only healthy male birds can afford to maintain a costly display of color by diverting resources away from the immune system, the theory goes. The male must therefore have good genes, and that's why a flashy male attracts mates. In the mating game testosterone plays a similar role to carotenoids. The hormone makes male birds strut and croon but weakens their immune systems, and researchers knew that variations in testosterone levels between birds and seasons tend to match up with variations in the brightness of colors. "

trhway 9y ago

There is a range of studies on various birds showing correlation between higher intensity/contrast of male feather colors and higher testosterone levels. For example: https://www.sciencedaily.com/releases/2008/06/080602121302.htm https://www.sciencedaily.com/releases/2008/06/080602121302.h... or https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3187837/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3187837/ or http://elitetrack.com/blogs-details-2765/ http://elitetrack.com/blogs-details-2765/ "Researchers may have discovered how the bright plumage of male birds evolved as a sign of health and vigor to potential mates. Testosterone, which weakens the immune system, increases the circulation of immunity-enhancing pigments called carotenoids, they find. Healthy birds let the pigment collect in the skin to flaunt their vitality. [/] The bright coloration of some birds is a classic example of an animal advertising its high quality to potential mates. Carotenoids are the pigment in red, orange and yellow skin (and carrots), but they are also powerful antioxidants that boost the immune system. Only healthy male birds can afford to maintain a costly display of color by diverting resources away from the immune system, the theory goes. The male must therefore have good genes, and that's why a flashy male attracts mates. In the mating game testosterone plays a similar role to carotenoids. The hormone makes male birds strut and croon but weakens their immune systems, and researchers knew that variations in testosterone levels between birds and seasons tend to match up with variations in the brightness of colors. "