@digs and @solost and maybe @Treppenwitz –
(and any other Dopers who are interested)
Based on your recent remarks in another current thread, this article may be of interest, in addition to being of potential interest to readers of this thread:
Can Animals Think? by Eugene Linden, Time Magazine, March 1993.
Discusses how, and how much, animals may be communicating among themselves (and with their humans).
In a sun-dappled pool not far from the clamor of Waikiki Beach, two female dolphins poke their heads out of the water, waiting for a command. “O.K.,” says Louis Herman, founder and director of the Kewalo Basin Marine Mammal Laboratory, “now let’s try a tandem creative.” Two graduate students, positioned at opposite ends of the 50-ft. tank, throw full body and soul into communicating this message to the animals, Phoenix and Akeakamai. First the humans ask the dolphins to pay attention by holding a finger high in the air. Then they tap the index fingers of each hand together, forming the gesture that has been taught to mean tandem. Next they throw their arms up in an expansive gesture that signifies creative. The dolphins have just been told, “Do something creative together.”
Also mentions Alex the Parrot, Koko the Gorilla, Clever Hans the Horse, and others.