While some birds avoid unwanted attention in suits of feathered camouflage, others shine in vibrant plumages intended to attract a lot of wandering eyes, specifically when it comes to mating season. The latter is true of flamingos, famously pink (and angry) birds that stand loud and proud under the beating sun. However, in time, the sun can dampen their hue as it bleaches out the color. However, new research has found that greater flamingos have adapted to don a kind of “makeup” to counter this fading effect by rubbing secretions from glands close to their butts onto their neck feathers. Talk about suffering for your art.
The research, published in the journal Ecology and Evolution, looked at a group of greater flamingos (Phoenicopterus roseus) from Camargue, southern France. They wanted to investigate if these secretions really were acting like flamingo “makeup” in looking at what happened to feathers that weren’t receiving the booty-gland cosmetic treatment.
The group of flamingos enrolled in the study all shared one defining trait: they were dead, having succumbed to a cold snap in February 2012. No longer in need of their colorful plumage, their contribution to evolutionary science meant the researchers could take their feathers for testing with a variety of conditions to see how it altered their appearance.
Flamingos' pinky-red color stems from carotenoids, a natural pigment that the bird has in great supply thanks to its diet of brine shrimp and algae. One way in which they utilize this excess of carotenoids is by excreting a secretion (which from now on we’ll generously call a “dye”) from the uropygial gland, which sits near the butt end.
The dye can be gathered on a flamingo’s beak and cheeks and spread across its feathers for an aesthetic boost. Color counts for a lot during the flamingo mating season, with birds with the most colorful feathers mating earlier and more successfully compared to their pale counterparts.
Using five to 10 feathers from the dead birds’ necks and cutting out their “dye” secreting uropygial glands, they tested if the sun really did have this bleaching effect on their feathers. They popped a bunch of feathers on the roof while others were kept in the dark and assessed how their color had changed over 40 days.
The researchers found that feathers with the highest concentration of carotenoids on their exterior or in their interior kept their color the best. This would appear to indicate that birds who keep their feathers in tip-top condition with a generous lathering of booty gland dye are more likely to maintain their vibrant color, likely giving them a helping hand during mating season.
“These results indicate that exposure to sunlight is correlated with the fading of feather color, which suggests that individuals need to regularly apply makeup to be more colorful,” wrote the study authors. “These results also reinforce the view that these birds use cosmetic coloration as a signal amplifier of plumage color.
“This result is consistent with the finding that the more colorful individuals apply cosmetics over their feathers more frequently than the less colorful individuals, which suggests that colorful individuals need to regularly apply makeup to be more colorful.”
Get preening, lads.
Have you ever seen Lake Natron's flamingos? They live in waters as caustic as bleach.
[H/T: Science News]