WASHINGTON – The monarch butterfly has nearly vanished from the western United States, its population down more than 99 percent from counts recorded in the 1980s. On Thursday, the Trump administration made it considerably harder to bring it back.
In a pair of rules issued by the Interior Department, the administration dismantled two foundational pillars of how the federal government protects species sliding toward extinction. The first rule strips threatened species of the automatic legal shield they have held since 1975 under the Endangered Species Act. The second rewrites how federal agencies designate critical habitat, requiring extensive economic analysis before protecting an area and allowing officials to exclude habitat even where a struggling animal currently resides.
Together, the changes represent what environmental law scholars describe as the most extensive rewriting of ESA implementation rules in the law’s 53-year history. They take effect immediately.
Interior Secretary Doug Burgum framed the changes as a correction of regulatory overreach accumulated across multiple administrations. “These revisions end years of legal confusion and regulatory overreach,” Burgum said in a statement accompanying the rules’ release. “They restore balance between species protection and the legitimate economic needs of landowners, energy producers, and local governments.”
Conservation groups and legal advocates saw it differently. Earthjustice attorney Kristen Boyles, who led her organization’s legal response to similar ESA revisions during Trump’s first term, said Thursday’s rules “undermine protections even more than in Mr. Trump’s first term,” according to CBS News. Lawsuits challenging both rules were filed before the day was out. The move extends a pattern of aggressive federal environmental rollbacks: Trump earlier opened Pacific marine national monuments to industrial fishing and auctioned Arctic wildlife refuge oil leases for the second time in his presidency.
The first rule removes what the ESA calls “Section 4(d) protections,” the provision that had automatically extended the full suite of endangered-species safeguards to species listed as merely threatened. For a species like the Florida manatee, which was reclassified from endangered to threatened in 2017, the federal prohibition on “taking,” meaning harming, harassing, or killing, will no longer apply automatically. Instead, federal agencies must now craft individualized rules for each threatened species, a process that can take years and frequently never happens.
Seventeen species currently listed as threatened have no existing individual protection rules. Under the old framework, they received full endangered-species coverage by default. Under Thursday’s new rule, that coverage disappears.
The Florida manatee’s population had recovered enough in 2017 to justify reclassification from endangered to threatened. Since then, the seagrass beds that sustain it have shrunk dramatically due to algae blooms fed by agricultural runoff, and dozens of manatees were killed by boat strikes in the past two years alone. Environmental groups had already been petitioning to return it to endangered status; that effort, they said Friday, is now considerably more urgent.
The second rule targets critical habitat designations. Under the ESA, the Fish and Wildlife Service and National Marine Fisheries Service are required to designate areas of land or water essential to a species’ survival when they list it. Thursday’s rule allows agencies to exclude areas from critical habitat designation if economic impacts, including lost oil and gas revenue, agricultural restrictions, and development costs, are deemed too high, even if that exclusion is likely to lead to a species’ extinction.
The rule also narrows what counts as “critical” habitat in the first place, excluding areas where a species is not currently found even if scientists judge those areas necessary for the species to recover its range. For the monarch butterfly, whose range has contracted so severely that it now occupies a fraction of its historical territory, formerly occupied habitat where it no longer exists would not qualify for federal protection.
Western states with significant public lands and fossil fuel extraction operations are expected to benefit most immediately from the critical habitat revision. Interior Department analysts estimated in the rule’s preamble that reduced critical habitat designations could unlock billions in resource extraction revenue over the next decade, though the analysis drew immediate criticism from conservation economists who said it did not account for the economic value of ecosystem services the habitats provide.
The California spotted owl and North American wolverine, both currently listed as threatened and both dependent on critical habitat designations to prevent logging and snowmobile-trail expansions from eliminating their remaining refuges, face similar exposure under the new rule.
The administration’s legal footing rests on a 2018 regulatory revision made during Trump’s first term that was challenged in court and ultimately vacated by the Biden administration. Thursday’s rules reissue much of that 2018 package with modifications intended to address the legal vulnerabilities courts previously identified. Earthjustice said it filed a complaint in the Northern District of California, and the Center for Biological Diversity said it was filing within hours.
Environmental legal analysts note that the administration’s changes face heightened scrutiny under the 2024 Loper Bright decision, in which the Supreme Court eliminated the Chevron deference doctrine that had previously given agencies wide latitude to interpret ambiguous statutory language. Under Loper Bright, courts must make their own independent judgment about whether agency rules are consistent with statutory text, a standard that may make the ESA rules more vulnerable to judicial reversal than similar rules were a decade ago.
What remains genuinely unclear is how long the rules will survive in court. The prior ESA revision lasted roughly two years before it was vacated. Legal observers expect a similar trajectory here. In the interval, permits for drilling, grazing, and development in previously protected habitat can be issued and acted upon. The legal challenge may ultimately succeed; the habitat it would have protected may not still be there.
