Cal. Rev. & Tax. Code § 6010.50

(a) For purposes of this part, “sale” and “purchase” do not include any transfer of an endangered or threatened animal or plant species acquired or disposed of through a trade or exchange between nonprofit zoological societies or between a member of the American Zoo and Aquarium Association (AZA) and a nonprofit zoological society.
(b) For purposes of this section and Section 6366.5, “endangered or threatened animal or plant species” means animals or plants that are any of the following:
1. (1) Listed in Appendix I, II, or III to the Convention for International Trade of Endangered Species.
2. (2) Listed as endangered or threatened by the United States Department of the Interior, Fish and Wildlife Service.
(c) For purposes of this section and Section 6366.5, a “nonprofit zoological society” includes both of the following:
1. (1) A zoological society operated for charitable, educational, or scientific purposes and qualified for exemption under Section 501(c)(3) of the Internal Revenue Code.
2. (2) A zoological park owned or operated by a city, county, or other instrumentality of any state or foreign government.