Humpback whales rank among the sea's noisiest creatures, emitting an assortment of grunts, low moans, and belches. Electrical engineer John Buck at the University of Massachusetts at Dartmouth recently analyzed the rumblings and found they appear to have a complex syntax, one of the key components of language.
After reducing two 45-minute recordings of whale cries to a series of symbols, Buck and his colleagues used a computer program to study the sequences. Unlike, say, bird calls, which consist primarily of simple, repeated patterns of notes, Buck found that the whales' songs, like human language, appear to have a hierarchical structure.
In speech, such structure allows sentences to be diagrammed and makes English grammar predictable. For example, says Buck, "If I say that I will wear either the red shoes or the blue shoes, once you hear the word 'either,' you know an 'or' is coming."
Researchers still need to show that the humpback sounds have specific meaning before the songs can be considered a language.