Territorial song and song neighbourhoods in the Scarlet Rosefinch Carpodacus erythrinus

Throughout the range of the Scarlet Rosefinch, its territorial song consists of 3–9 (usually 4–5) elements, of which there are 5 different types. The differences lie in the way the pitch of the element changes in time (frequency “slope”) and the width of the frequency band. Within a given type of song, the various elements can be present in almost any combination. Therefore, so many song types can be formed that the songs in even small parts of the species’ area are clearly distinct from one another. Despite this capacity for variation, however, by chance identical songs may be sung in widely separated parts of the area, in some cases by different subspecies. The species has not developed l…