Call Duck questions

[TSOWOATNKC]

What makes people choose to have calls? Other than the little and cute factor is there something different about Call ducks that is particularly desirable? Are calls a specific breed, or a genetic abnormality that has been cultivated into a subset?

 

[chickens really]

They are an ornamental breed of Duck and and adorable.
Were used to call in wild Ducks by hunters..