In the early Spring you can often hear pairs of Pied-Billed Grebes "duetting" together. Duetting is when two birds of the same species (usually a male and a female) sing together, often interleaving their parts of the song together seamlessly, as in this example. These were recorded March 22, 1998 in the morning at Peck's Lake [Arizona].
Douglas Von Gausig (recordist; copyright holder), Naturesongs.com
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