There are many species in the animal kingdom that have the ability to change color in order to send a message. This has been more commonly observed in fish and reptiles but other mammals and birds are able to do this as well. This gives a quick and easy signal that relays information about the animal very rapidly.
One recent article finds that Lappet-faced vultures, (Aegypius tracheliotos), in Nambia can do this as well. These scavengers' heads can become bright red from flushing, or increasing blood flow to the skin. Dr. Bamford and his colleagues found that vultures with red heads won more social interactions against other vultures without red heads. In addition to this, Bamford found that there was another color variation of the throat that the vultures could use. Instead of the usual red more dominant vultures had blue throats and won more interactions against others whose throats were not blue. With this Bamford concluded that, "...face flushing status plays an important part in the initiation of, and response to, interaction from other vultures."
These color signals that vultures use suggests that signals of dominance evolved to be adjusted very rapidly. Fast signals allow for quick interpretation and could be beneficial for less dominant vultures to know when to back off from dominant ones and avoid injury. Although we make do with tweets and status updates, it would be interesting if we could change the color of specific body parts on command to signal our mood as these birds do.
Posted by Daniel Solomon
Wow that's really interesting! I'm curious to whether this plays a role in mate selection among female vultures. Has there been any research done that tests these color variations with sexual selection and fitness? Also, how do they increase blood flow to their skin? Is this increase in blood flow due to territorial disputes, or is it something they can turn on and off?
ReplyDeleteAbbie Lamarre-DeJesus
As mentioned previously, do vultures have direct control over the color changes? I read an article once that discussed blushing in humans, which is involuntary. The researchers at the time still could not figure out whether there is some sort of evolutionary reason behind blushing. It is also caused by increased blood flow to the skin, so do you think the behaviors are somehow related?
ReplyDeletePosted by Katie Kalutkiewicz
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ReplyDeleteVery fascinating! Do you know if any of the vultures share both red faces and blue throats? What kind of social interactions take place with the flaring of red coloration in the head or blue in the throat? Are they fighting or performing mating rituals? Does the blue color become richer like the red or does it remain the same at all times whether interacting with other vultures or not? Thanks for your post! I found it really interesting!
ReplyDeletePosted by Shyla Morsbach
As Katie said the flushing is due to an increase in blood flow through the skin. So they can control it but I'm unsure if they're aware of it or not. It may just be a automatic response when they're fighting against others. Vultures would only have the blue throats if their heads were red as well. The research was done when the vultures were fighting each other not mating (agonistic interactions). Not much research has been done on flushing behavior so it unknown if it plays a role in mating rituals. Yet, since red necked, blue throat vultures win more fights they may use them when fighting off other males during mating season.
ReplyDeletePosted by Daniel Solomon
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ReplyDeleteIt would be intersting to know what the colors mean. Maybe blue is a more intense message than red or maybe they mean two different things completely. Do you know?
ReplyDelete-Meghan Nichols