California Code, Fish and Game Code - FGC § 4600

(a) It is unlawful to kill, wound, capture, or have in possession any undomesticated burro, except as provided in Section 53074.5 of the Government Code.

(b) As used in this section, “undomesticated burro” means a wild burro or a burro which has not been tamed or domesticated for a period of three years after its capture.  The fact that a burro was killed, wounded, or captured on publicly owned land, or on land owned by a person other than the person who killed, wounded, or captured the burro is prima facie evidence that the burro was an undomesticated burro at the time it was killed, wounded, or captured.

(c) Neither the commission nor any other department or agency has any power to modify the provisions of this section by any order, rule, or regulation.