JACKSON (WNE) — Wolverines are once again proposed to be listed as “threatened” under the Endangered Species Act.

That’s the result of a Wednesday ruling in federal court that marked the latest swing in a decades-long see-saw over the mustelids’ status under federal law.

Judge Donald Molloy, of the U.S. District Court for Montana, said in a 15-page decision that the U.S. Fish and Wildlife Service must revisit a 2020 decision in which it decided against listing the species as “endangered” or “threatened.” Molloy said that “serious errors undermine the Service’s decision” and gave the agency 18 months to reconsider its ruling.

Molloy’s order came after environmentalists challenged the 2020 decision to withhold protections. They argued that wolverines face localized extinction as a result of climate change, habitat fragmentation and low genetic diversity.

The 2020 decision, which came under the Trump administration, was based on research suggesting the animals’ prevalence was expanding, not contracting.

Biologists estimate that fewer than 300 wolverines exist in the lower 48 states, where environmental groups are calling for them to be listed. Populations in Canada and Alaska are relatively healthy.

Wednesday’s decision doesn’t offer wolverines protection under the Endangered Species Act.

It also won’t change much of how wolverines are managed in Wyoming. The state considers them a “Species of Greatest Conservation Need” and manages them as non-game species, meaning hunting them is prohibited.

Between 2001 and 2008, researchers identified four adult wolverines regularly inhabiting the Tetons, with kits — in the years they were reared — beefing the population up to seven. But in 2015, researchers trying to determine the impacts of backcountry recreation on wolverine numbers in the Tetons were only able to find one animal.

State wildlife officials were unavailable Friday to update those numbers.