Call AND write the city (send your letter certified so that there is a record of it having been sent and received) asking them to provide you with the specific reference in city code/ordinances that they say you are violating. You may have to go down to city hall to read the ordinances if they are not available online. Note, you are not asking them if keeping chickens is legal or illegal, you are asking them to cite the code or ordinance that would render chickens as illegal. If they cannot give you a specific ordinance, then you need to tell them that due process requires that laws be properly enacted--that you cannot break a law that does not legally exist.
Tell them that until you have read the law yourself and verified that chickens are disallowed, you will be keeping your birds. Then post No Trespassing signs on your property and on your coop. Securely lock the gates/doors, or better yet, move the birds into your house or garage where they can be secured from seizure; where a judicially issued warrant would unequivocably be required.
Tell them that until you have read the law yourself and verified that chickens are disallowed, you will be keeping your birds. Then post No Trespassing signs on your property and on your coop. Securely lock the gates/doors, or better yet, move the birds into your house or garage where they can be secured from seizure; where a judicially issued warrant would unequivocably be required.