California Enacts Increased State Law Protections for Federally Listed Species

Key Takeaways

• California recently enacted Assembly Bill 1319, which provides increased state law protections for federally listed species that may be affected by rollbacks in the protections afforded under federal law.
• AB 1319 is another example of California providing enhanced environmental legal protections under state law to fill in the gaps created by reduced federal law protections. 

California Governor Gavin Newsom signed Assembly Bill 1319 into law on October 11, 2025, which provides enhanced state law protections under the California Endangered Species Act for those species native to California that may be affected by the recently proposed rollback of protections under the federal Endangered Species Act (ESA). 

Background

The background for the enactment of AB 1319 involves the complex interplay of the federal and state statutes protecting endangered and threatened species, the recent retraction of judicial deference to federal administrative agencies, and the proposed rollback of species protections under the federal ESA.

The federal ESA prohibits the unauthorized “take” of species that are listed under the act as endangered or threatened. The ESA’s definition of “take” includes actions that “harass, harm, pursue, hunt, shoot, wound, kill, capture, collect” any listed species or “attempt to engage in any such conduct.” ESA § 3(19), 15 U.S.C. § 1532(19). The term “harm” is defined by federal regulations to include actions that result in “significant habitat modification or degradation which actually kills or injures fish or wildlife by significantly impairing behavioral patterns, including breeding, spawning, rearing, migrating, feeding, or sheltering.” 50 C.F.R. §§ 17.3, 222.102.

In 1995, the U.S. Supreme Court upheld the regulatory definition of “harm” in a 6-3 decision, deferring to the federal government’s interpretation of the ESA. Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995). But the dissent, authored by the late Justice Antonin Scalia, opined that this definition was not reasonable and should not be upheld. According to the dissent, the ESA’s definition of “take” should be construed to cover only “affirmative acts … directed immediately and intentionally against a particular animal—not acts or omissions that indirectly and accidentally cause injury…” 515 U.S. at 719-20 (Scalia, J., dissenting). 

The majority decision in Babbitt was based on the principle, as established in Chevron U.S.A, Inc. v. Natural Resources Defense Council, Inc., 468 U.S. 837 (1984), that courts should defer to a federal agency’s reasonable interpretation of an ambiguous statute that it is charged with administering. But the Supreme Court recently overturned its prior decision in Chevron in Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024). Under Loper, a federal agency’s interpretation is no longer entitled to judicial deference—instead, this interpretation is now just one factor for a court to consider in determining the “single, best meaning of the statute.” For more on the Loper decision, see our prior Update on this major change in federal administrative law.

In April 2025, the two federal agencies that are charged with implementing the federal ESA—the U.S. Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) of the National Oceanic Atmospheric Administration—proposed to rescind their regulations defining the word “harm,” without providing any replacement definition. See 90 Fed. Reg. 16,102 (Apr. 17, 2025). The proposed rule is based on the federal government’s position, pursuant to Loper, that the regulatory definition of the term “harm” does not represent the “single, best meaning” of the ESA’s text.

If the proposed regulation becomes final, it is anticipated that federal protections against habitat modifications affecting listed species will be diminished, and the term “harm” under the ESA will be applied consistent with Justice Scalia’s dissent in Babbitt. In response, California enacted AB 1319 to enhance the protections afforded to such affected species under the California Endangered Species Act.

This state law contains its own distinct procedures for listing species as threatened or endangered. While there is overlap between the federal and state species lists, the two lists are different, and there are more than 100 federally listed or candidate plant and animal species native to California that are not state-listed. The California Endangered Species Act also contains a separate definition of “take” and a distinct process for obtaining an incidental take permit from the California Department of Fish and Wildlife (CDFW). And importantly, the state law contains stricter mitigation requirements than the federal act, mandating that any impacts resulting from a take of a state-listed species must be “minimized and fully mitigated.”

AB 1319

The newly enacted state law applies to those species that (1) are native to California; (2) are listed or are candidates for listing under the federal ESA as of January 1, 2025; (3) are not listed under the California Endangered Species Act; and (4) could face a decreased level of protection under the ESA because of a federal statutory or regulatory change. 

For these species, AB 1319 requires the CDFW to monitor actions by Congress, the USFWS and NMFS, and the president “that could result in a decrease in endangered or threatened species protections by the federal government.” For any action that CDFW determines will result in such a decrease, CDFW must then determine whether this decrease “will have a substantial impact” on one or more covered species in California and whether provisionally listing the affected species as a “candidate” under the California Endangered Species Act “could significantly reduce any such substantial impact.” If CDFW makes these two findings, then it must publish written findings that designate the species as a “provisional candidate species” on the state’s species list.

Once this designation is made, “provisional candidate species” are entitled to the same protections as “candidate” species. This is significant because under the California Endangered Species Act, candidate species are entitled to the same protections as state-listed endangered and threatened species. This means that a state law incidental take permit from CDFW is required for any take of a provisional candidate species, although such a permit is not required where an entity is already operating in compliance with a federal take authorization in effect on or before January 19, 2025.

Provisional candidate species will remain designated as such until AB 1319 sunsets at the end of 2031. However, the California Fish and Game Commission (Commission) may remove the designation before that time in accordance with the existing procedures under the California Endangered Species Act for determining that a candidate species does not qualify for listing as threatened or endangered. Conversely, the Commission may proceed with the formal listing of a provisional candidate species as threatened or endangered if it determines that ongoing protection is warranted beyond the provisional status provided by AB 1319. 

Implications

The most obvious implication of AB 1319 is that more species are likely to be added to the state’s list of protected species under the California Endangered Species Act. It is uncertain how many species will be added to the list as provisional candidate species, but in general, landowners and developers can expect some level of increased state law regulation and liability for activities with potential impacts to species. 

Further, under pre-existing state law, when a species is designated as a candidate for potential listing as endangered or threatened, that designation generally triggers a 12-month timeline for the Commission to decide whether the species should be listed or not. But under AB 1319, unless the Commission decides to proceed with the formal listing or removal process, there is no such timeline for provisional candidate species, which can thus remain under this temporary designation until the law sunsets at the end of 2031. Given the backlog already facing CDFW and the Commission for listing and delisting decisions and the processing of incidental take permits, the addition of the provisional candidate species designation is likely to create greater uncertainty and longer permitting timelines for landowners and developers when there are potential impacts to species.

Lastly, while AB 1319 provides a safe harbor where a federal take authorization has already been issued, this only applies to such authorizations that took effect on or before January 19, 2025. Federal take authorizations issued or modified after that date cannot be relied upon for a take of a provisional candidate species, which means that increased mitigation requirements are likely to be imposed for impacts to such species pursuant to the strict “fully mitigated” standard that applies to the issuance of incidental take permits under the California Endangered Species Act. This heightened mitigation standard already causes delays and added costs as part of the state permitting process for species that are listed under both federal and state law, and AB 1319 will likely exacerbate this issue for landowners and developers.