Occasionally, especially in the quiet times of the morning, chorus can be heard. Chorus sounds like many birds calling in turn. Chorus seems to be the result of many brief, short-path whistler-like emissions occurring at almost the same time.
Chorus (882k)
-*- Chorus and sferics (294k)
-*- More chorus and Sferics (113k)
-*- Very loud chorus (248k)