For the first time, scientists have caught footage of Egyptian vultures putting makeup—actually mud—on their heads and necks.
This is an example of a rare phenomenon, in birds at least, called cosmetic coloration. Cosmetic coloration is when birds use specific substances to change the color of their plumage. Scientists say that birds may do this to attract a mate (much like humans do!), though this still needs confirmation.
Researchers recently came upon Egyptian vultures living on Fuerteventura Island in the Canaries. They were able to capture videos of vultures putting on their mud makeup, which is the first footage of its kind.
Egyptian vultures have naturally white feathers on their heads and necks. Researchers detailed in their study that they saw vultures with reddish or brown feathers instead. Some have even dyed their feathers a crimson color.
There's a process to getting color into these feathers, much like how there's a process to putting on human makeup. The vultures bend and dip their head into the dirt, making sure to get dirt all over their head, neck, and chest. They go about this process carefully and thoroughly.
The researchers set out two bowls for the vultures: one that had a mixture of water and red soil, and one with just water. And thus, the researchers watched as the vultures examined the contents of the two bowls. 18 out of 90 bird visitors dyed their heads red in the first muddy bowl. A couple of the vultures even went back for a second layer.
Aside from the groundbreaking video footage, there's another thing that makes this study special. The vulture population in this study has featured in many others, and scientists have already tagged them. This means that each vulture is distinguishable from the others. Thus, the researchers were able to identify cosmetic coloration differences in each individual.
Observations showed that individual vultures had different preferences when it came to coloration. Some remained almost completely white, while others chose to become almost completely red. The researchers also found that though the vultures were quite thorough with their mud baths, the process wasn't complicated. Any vulture can also participate in the makeup sessions, no matter the age or sex.
Though the researchers know all this information, there's still a key piece of information missing: why the vultures do this. There are, of course, a number of possibilities. It may be that the mud baths keep microbes and viruses away. However, if this were true, the baths should be much longer than they are.
A more plausible explanation is something that has to do with visuals. After all, brown and crimson feathers are a stark difference from white feathers. Reddish mud makeup is also rare, as the researchers found out. This may mean that there is some significance or importance attached to the color. More research is necessary to pinpoint the exact reason for cosmetic coloration in Egyptian vultures. Is it for health, reproductive purposes, or to signify some sort of bird hierarchy? Perhaps time will tell.
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