[Tamsjute]

Having just got my first ducks earlier this year I have found a lot of ppl very particular about their call ducks, how big they are, colouring, so on and so forth - but how do actually know if they are true call ducks or just small noisy ducks???
Not that I'm particually geting into breeding them, just curious. 

[Brucklay]

Will amplify tomorrow  as a long day today but - yes girls are vocal and boys are more rasspy and eventually get a curly tail - then there are all the colours - white, silver, grey/mallard, apricot, light apricot, bibbed, blue bibbed and magpie of a couple of colours and then you can have a call duck cross colour - they don't always go for their own!! I love them - free range and let them do their own thing - I do think they benefit from free grazing, they love bugs.

[Womble]

Not that I'm particually geting into breeding them, just curious. 

Unless you're into breeding or showing, I'd say that if it looks like a call duck, swims like a call duck, and quacks like a call duck, it probably is a call duck! 

[Penninehillbilly]

They should be chubby little things, body less size than a bag of sugar, 'forehead' come down at an angle to the beak rather than what I called a 'ski slope'. They should really have a distinctive quack, I used to call them laughing ducks, they sounded like they were have a good old joke amongst themselves.
I loved to watch mine 'hoovering' across the lawn, looked lovely when a dozen or so were working their way over in a little gang, beaks finding anything tasty.