Food and Agricultural Code § 25855
CHAPTER 4. Poultry and Rabbit Meat Classes
The following are the various classes of ducks:
(a) “Duckling” means a young duck of either sex (usually under 10 weeks of age) that is tender meated and has a bill that is not completely hardened and windpipe that is easily dented. This classification may include broilers, fryers, or roasters.
(b) “Duck” means a mature duck or an old duck (usually over 10 weeks of age) of either sex with toughened flesh, hardened bill, and a hardened windpipe.