So Google Image search shows that some chimpanzees have pink faces, and some have black or grey faces. Is it the ape version of different ethnic groups? Is it an age thing? Sun exposure? Or is just random variation, like humans having blond or brunette hair?
I’m not sure about that, but if you search for “bald chimp” or “hairless chimp” you’ll see similar types of coloration differences in their whole bodies.
Young chimps have pink faces. Their faces get darker as they get older. The reason we think of chimps as usually having pink faces is that the ones used in the media are almost invariably juvenile chimps. Juvenile chimps are cute and eager to learn and docile. Then then become teenage chimps. Mature chimps have been known to chew off people’s faces.
Thanks for clearing that up, I didn’t know that it was an age thing.