Cal. Fish & Game Code § 3305

All domesticated migratory game birds at time of release for shooting shall be at least 14 weeks of age, capable of strong and sustained flight, fully feathered, and otherwise in condition to survive in the wild. Birds that are altered in any manner which would, in the opinion of the department, render them incapable of normal sustained flight, or which are diseased, or show evidence of malnutrition or injury, shall not be released.