Hi there, hope you are enjoying BYC!
My chrome book won't open the last link in the first paragraph on this page...
http://wp.sbcounty.gov/dph/programs/acc/animal-laws-welfare/
They may be referred to as waterfowl, livestock, or poultry. And it will depend if you are city limits or county.
If all else fails.. call code enforcement or animal control and ask your questions. My links are for San Berdu (locals name), but your should be able to easily find the same things for Riverside county.
http://cms.sbcounty.gov/lus/CodeEnforcement/CodeEnforcementHome.aspx
For what it's worth... you cannot legally bring ducks or any other poultry, even hatching eggs across state lines without being NPIP certified
or getting a certificate of health for your flock from a veterinarian. California does have agricultural inspection stations on all major highways entering the state. They are mostly trying to protect crops from a specific fruit fly, but I would hate to face any complications with pets!
I know Southern California, including parts of those counties, were effected by the virulent New Castle's outbreak earlier this year and no birds were allowed in or out of the quarantine zones initially and eventually mandatory euthanasia of all backyard flock within those zones.

Since I am mostly a chicken person, I am unsure how that effected ducks... but something worth looking into for you probably...
State link...
https://www.cdfa.ca.gov/ahfss/animal_health/newcastle_disease_info.html
Fed link..
https://www.aphis.usda.gov/aphis/ou...ease-information/avian/virulent-newcastle/vnd
Hey, sorry you're moving to So Cal! But hope it goes well for you and you love it there.
If you aren't bringing current birds with you... I do highly recommend
https://www.metzerfarms.com/ a good source for waterfowl if they have the breeds you like, once you're ready.
