Figure 1. The unison duet of the forest weaver.

We show a sonogram of a field recording of a breeding pair of forest weavers from Fannie's Island. To better illustrate the fact that 2 animals are participating with the same syllable repertoire, we selected a duet in which bird 2 sings with a delay of about 90 msec. “1” and “2” indicate the onset of syllables produced by either bird. In many cases the animals duet with an offset of less than 10 msec.