Sorry I missed this post, I hope you won.
I would have approahed this 2 ways, one the letter of the law.
Websters dictionary:
Domesticated animal - Species in which the evolutionary process has been influenced by humans to meet their needs
Tame - Make (animals) fit for cultivation, domestic life, and service to humans; "The horse was domesticated a long time ago"; "The wolf was tamed and evolved into the house dog".
Chickens , by definition are tamed and domesticated animals. The section of the law that gives one pause is "commonly inside a residence.". The thing to do with this one is laugh it off, to attack it is to create an argumentitive situation, and that even if you win by intellectual points, you wont win on an emotional level. I would however present pictures form this board and others like it that show chickens inside with their owners .
My close would be pictures like the ones you have above, your kids with the birds, and say to them , that you understand that the spirt of the law was to allow animals for pets only, do you really want to tell my children that you see in these pictures that these are not their pets.
If you have a bird that would allow one of your kids to hold it for a prolonged period of time, it would hurt to have them both sitting in the audience.
Dont argue, sell.