why do people say "bird brain" ? Birds are smart!

I hear you! That term irritates me. People who think birds are dumb really need to spend some time with one. At least people are starting to recognize how smart parrots and crows are, even though that intelligence extends to other avian species as well.

I actually did some research about origins of animal idioms not too long ago. It seems that nobody knows for sure where "bird brain" came from, but some etymologists think it's either due to the small size of the brain, or because birds are "flighty" and easily distracted. I still think the phrase needs to be stricken from the language!