Alternate links: Google News | Twitter

Significantly, Dahlin said, they found what are known in human language as collocates, words that are often paired together"for example, "eat" and "food" or "grass" and "green."

The group uncovered more than 20 syntactic rules that the duets followed. Even so, there was very little repetition within a duet, which lasted for 5"10 seconds. "This shows that the parrots are being very precise," Dahlin said. "They are not simply throwing random notes around."