They also seem to transcend species...
I happen to note that animals have the same sorts of expressions which I've learned to read in my human counterparts. In my "micro" studies, I have observed not only the facial language, but voice, body language as well.
My macaw, Sky, who will be 10 years old this year, gave me new challenges learning to read a bird as opposed to the regular, more down to earth, animals, like my cats who climbed a mountain or my dog who retrieved only my errant golf shots.
I noted that what I considered my "smarter" dogs were the ones who were reading my expressions. Doller Bill, a tiny mutt with big expressive eyes, knew me so well I never taught her anything, she LEARNED me.
Sky is different, oh so different. In a good and challenging way.
There were forums and websites explaining the language of parrots, but somehow they always came up short.
Then one day I suddenly could see her facial expressions and even understood them. It was like the moment that the picture turns 3D and all that staring pays off.
Sky is really incredible, taking her frame by frame in only a few videos I actually learned more about her. The moody creatures that parrots are, I can put the face to the mood, and avoid confrontation with the beak...if you know what I mean.
Knock on wood, but I've been able to read her better therefore I've had less bites. Yeah, some narrow misses, but that's the fun of it.
My blue and Gold macaw, Sky, looks "irritated"--studying microexpressions in my little cutey pie.
I think I'll call this one, "feigned indifference."
"Happy Camper" not scientific but fitting.
"Joy to the world!"
And then this look...hmm, they are so cute, but you just can't trust "quick jaw macaw."