RFI Birdsong

["Stephen Martin" <>]

Hello 

I'm currently researching for a book on humpback whales, to be 
published next year (I hope).

While researching, I've spoken to Cetaceans and read articles, who 
(and which) claim that humpback whales are the only known species to 
have 
a) geographically distinct 'songs'(regional differences)
b) change these 'songs' 
and which
c) sing for more than a few seconds.

I know that this is incorrect I've heard many bird species sing for 
much longer than 'a few seconds' and I understand that butcherbirds 
have regional variations - not to mention lyrebirds.

Could someone please steer me towards an authoritative source for 
confrmation or refutation please ?

Thanks 

Steve

                        Stephen Martin
                 State Library of New South Wales
                      Sydney, Australia