Out of a tangled skein of observations of animal communication, some common strands emerge. The profound effect of human language on human thought positively leaps out. Humans--no matter where we live--acquire an incredibly complex language so early in life that it colors everything we think. In fact, memories of events that occurred before we had words to describe them remain hazy and vague--if we can remember any such early events at all. And we are so steeped in our ability to symbolize reality that we tend to forget the difference between the symbol and the reality.
It's no wonder, then, that we think of animal communication in terms of human language. We tend to measure animals' ways of communicating against the "standard" of human language. Scientists, linguists and philosophers argue about whether apes can truly communicate in human sign language or with arbitrary symbols organized in a humanlike grammar. But we know relatively little about apes' natural modes of communication
Humans harbor an acute conscious awareness of communicating. But do animals? A wide spectrum of conscious awareness exists between the extremes of composing a sonnet and an unconscious knee-jerk reflex, but scientists and philosophers have laid animal communication at each end. A safe stance would call animal communication neither a poem nor a twitch. But placing animal communication more precisely on the spectrum may prove difficult. Even in the case of talking parrots, the animals best able to imitate human language, and the great apes, our nearest relatives and probably the "smartest" non-human animals, we know little about how conscious they are of communicating, and researchers do not agree on how much their behavior resembles human language.
Chapter 8 in our textbook does a great job at describing what nonverbal animal communication and how animals communicate. To learn more in depth about this topic read an excerpt from the book Animal Minds by Donald R. Griffin.