6. Guard calls
Generally, K-RC display much more GC than J-RC do. Moreover, many GC of K-RC sound completely different. Whereas the J-RC GC is more like we know GC from other crane species, the K-RC can display both the "normal" GC as also a "chatter", sounding more like a flight call.
Conclusions
It might be of interest that I have not succeeded in provoquing a unison call (or even a guard call) from a K-RC using J-RC unison calls (which I have on CD and replayed via megaphone). Not a single reaction based on this. GC were only displayed towards us when we were seen and in their view too close to the pair.
Several features of the calls, like
- length
- number of female answer calls in one tact
- complexity of frequency pattern
- level of main frequency of both males and females
- the call pattern itself (the call "structure")
- and the sound and form of the guard call
show basic differences between Japan and China / Korea.
This supports the hypothesis that the Japanese population was separated from the mainland since sufficiently long time to allow the development of at least a "dialect", if not a completely different "language". My impression is, that the differences are as strong as between RC and Whooper Cranes.
