There are noise ordinances here, too, but due to California's budget crisis, they do not have the ability to enforce it... so code enforcement cruises around and looks for code violators, including people with free-roaming "livestock" (chickens), so they can be cited and fined. That's their whole way of trying to bring revenue into the city.
My thought is that if the city sells permits to citizens to keep up to half a dozen chickens in their backyard, as long as they are not violating any CC&Rs in a subdivision or HOA community, I think that would generate far greater revenues for the city than fining individuals just for keeping chickens.
On the flipside of that, the city could continue to fine those out of compliance (i.e., if there is a permit for 6 chickens, and somehow you end up with 10 or 20), then I think a person should be given perhaps 5 business days to come into compliance or be fined.
Who will oversee this? Well, who oversees it now?
I think it would save at least 1 or 2 law enforcement positions in the city, which we desperately need.