Wild birds are indeed the main way that avian influenza spreads, however `ars` is just grinding some axe of theirs. California does not have a free-range chicken regulation. Virtually all commercial chicken flocks in California are already housed indoors. The California "cage-free" regulation only enforces minimal standards against cruelty. It essentially codifies these industry guidelines: https://uepcertified.com/wp-content/uploads/2021/08/CF-UEP-G...