Eh, I think your definition leans too much on the particulars of human communication. Take, for example, a scrub jay initiating a red tailed hawk to scare othe

Eh, I think your definition leans too much on the particulars of human communication. Take, for example, a scrub jay initiating a red tailed hawk to scare other birds away from a food source. It's a pretty common occurrence. There's no common language per se, but creating the illusion of a hawk is a kind of propositional statement that there is a predator nearby. The nearby animals believe that there is a predator, so they leave - that's a belief formed by the deception. It's worth checking out Carl Safina's 'beyond words', which is about animal minds and communication. You can definitely overdo anti-anthropomorphization - an huge amount of the hormonal signaling systems underlying many of our feelings match across an incredible array of animals. For a long time scientists denied that animals experience pain, which is just incredibly wrong - in addition to observing behavior, we also know now that the chemical signals are the same ones we use. One still needs to be a very careful observer and formulate and test alternative hypotheses, but the days of treating animals as unfeeling unthinking machines are thankfully behind us. (Well, except for the industrial meat system... But that's another conversation.)