From Wikipedia: "Animal communication is the transfer of information from one or a group of animals (sender or senders) to one or more other animals (receiver or receivers) which affects either the current or future behavior of the receivers. The transfer of information may be deliberate (e.g. a courtship display) or it may be unintentional (e.g. a prey animal detecting the scent of a predator). When animal communication involves multiple receivers, this may be referred to as an "audience". The study of animal communication is a rapidly growing area of study and plays an important part in the disciplines of animal behavior, sociobiology, neurobiology and animal cognition.Even in the 21st century, many prior understandings related to diverse fields such as personal symbolic name use, animal emotions, learning and animal sexual behavior, long thought to be well understood, have been revolutionized."
In an ancient Indian story called "Vikram and Vedal", the king Vikram is known to understand many animal languages including birds languages. In Wotan's famous opera "Siegfried" from the Ring Cycle, we know that the epic hero - Siegfried - learns from a Woodbird (forest bird) and gets the warnings.
I also recently read an article in a Science magazine about understanding dogs language & how the pet-dogs regard their owners etc.
Your views are welcome.. Muchas Gracias !!