Harry R. Schwartz

It seems that the Campbell’s Mona Monkey of the Ivory Coast uses syntax in its communication:

If the Zuberbühler team’s observations are correct, the Campbell’s monkeys can both vary the meaning of specific calls by adding suffixes and combine calls to generate a different meaning. Their call system, the researchers write, “may be the most complex example of ‘proto-syntax’ in animal communication known to date.”

—The New York Times

I’m pretty sure these little guys couldn’t learn sign language, and that’s a shame.