animal song is not a well-defined term in scientific literature, and the use of the more broadly defined term 'vocalizations' is in more common use. song generally consists of several successive vocal sounds incorporating multiple syllables. some sources distinguish between simpler vocalizations, termed “calls”, reserving the term “song” for more complex productions. song-like productions have been identified in several groups of animals, including cetaceans (whales and dolphins), avians (birds), anurans (frogs), and humans. social transmission of song has been found in groups including birds and cetaceans.