The sonograms presented show all song phrase types and their variants of territorial males tape-recorded since the species' song was recorded for the first time in 1999. The x-axis is time (0-2 s), the y-axis frequency or pitch (0-12 kHz).
Each male has a limited repertoire, which it sings year after year. The repertoire consists of one to four phrase types, each with a variable number of middle and end notes. Some males sing very distinctive songs, others share some phrase types, but can usually be distinguished by minor details and/or by other parts of their repertoire. Neighboring males with a phrase type in common, tend to use it more while countersinging, than while singing alone. A young male may learn quite complicated phrases from the adult male, to a degree where songs of the two can be told apart only with difficulty.
For much of the year song is limited to a single or a few phrases given at dawn, and at the end of the dry season, song ceases altogether.
During the breeding season, the male sings most frequently just before and during nest building, again for a few days after the eggs hatch, and finally after fledging of the young, when he guides them very carefully for a few days, singing for nearly every change of perch. This latter period may be the most important for song learning. The young stays with its parents for almost a year, but mates and sings when one year old.
Once established, most males remain in the same territory all their life. The sonograms have therefore been arranged under the territories where the songs were recorded.
Because only few birds have been color-banded so far, an estimate of the turnover rate in males (40%) was made on basis of differences in song. The attachment below (Male turnover.xls) indicates which songs were considered to be given by the same individual as the previous year. For further notes on vocalizations see Krabbe (2004).