The Sacramento Mountains checkerspot butterfly is only found in the far southwest corner of New Mexico, near the state’s borders with Arizona and Mexico and the small community of Cloudcroft. While it’s a local specialty, not many people living in the area have seen it or even heard about it. And for good reason: Recent surveys by biologists found only eight of the orange, black, and white butterflies, and no sign of eggs.

But even as the species teeters on the edge of extinction, the federal government hasn’t stepped in to save it. In 1999, when the insect’s population still numbered above a thousand, the nonprofit Center for Biological Diversity petitioned the US Fish and Wildlife Service (FWS) to grant the butterfly legal protection under the Endangered Species Act (ESA). Since then, the agency has received and declined another petition to list the vanishing critter, and is presently considering a third

The ESA is one of the most powerful tools in fighting the massive biodiversity crisis gripping the world right now. Yet examples of omission like the Sacramento Mountain checkerspot’s are all too common. 

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A study published this week in the journal PLOS identifies a few troubling trends in the way the FWS administers the ESA. It points out that species are often not listed until their populations have already reached perilously low numbers, and that, on average, the agency takes nine years to deliver verdicts on petitions that are supposed to be decided within two. 

One reason for this bottleneck is administrative. “The number of species listed for protection under the Endangered Species Act has more than tripled since 1985, but funding for the Fish and Wildlife Service hasn’t kept pace,” says Erich Eberhard, a PhD candidate in ecology at Columbia University and lead author of the research. 

Some of the species listed with low numbers were driven to that point even before conservationists petitioned for their listing. Eberhard points to the Mariana mallard and the Guam broadbill, two bird species that received protection relatively quickly in the 1970s and ‘80s, but whose populations were less than 100 apiece at the time of listing. Both are now extinct. The paper identifies small population sizes at the time of listing (as in the case of the birds) and long petition wait times (as in the case of the checkerspot butterflies) as two issues that hinder the act’s effectiveness.

Noah Greenwald, the endangered species director at the nonprofit Center for Biological Diversity, has seen similar trends detailed in the study over the 20 years he’s spent working on petitions to get species listed under the ESA. He doesn’t only attribute it to limited capacity on the FWS’s part, though. 

“Some of it is just bureaucratic malaise,” says Greenwald. “The process for listing species is terribly cumbersome.” The review process, he points out, includes more than 20 agency officials. 

Rare butterflies are just a few examples of how
The Sacramento Mountain checkerspot butterfly is on its third ESA petition. Julie McIntyre/USFWS

The language of the ESA is clear that the decision to designate a species as “endangered” or “threatened” should be based solely on the best available science. Given that, Greenwald suggests that a process more like peer-review for academic studies, where other experts in the field evaluate the evidence in a petition, would be more streamlined and effective than what the FWS currently does. 

Political decision-making can also make the ESA slower and less effective. Since taking office, President Joe Biden has undone measures that former President Donald Trump put in place to severely limit the act’s scope. What’s more, for the last couple decades, the number of protected species has fluctuated depending on the party in power, with Trump listing fewer on average than any other president since the ESA was enacted. 

[Related: The monarch butterfly is scientifically endangered. So why isn’t it legally protected yet?]

Both Greenwald and Eberhard are quick to say that the ESA has been highly effective at protecting the species that do end up being listed, which right now includes around 1,300 species. More than 99 percent of them have survived, and 39 former members of the list have fully recovered. But with 9,200 species considered “imperiled” or “critically imperiled” by biologists in the US, that success rate only reflects a piece of the country’s biodiversity needs. 

Given the ESA’s proven effectiveness at protecting species when it’s invoked, the study suggests giving FWS more resources to consider petitions and reach verdicts quickly. “The Fish and Wildlife Service is receiving less funding now on a per species basis than in the past,” says Eberhard. “What we need is a more serious investment.” 

For some wildlife, like the Sacramento Mountains checkerspot butterfly, the lost time between filing a petition and receiving protection is critical, potentially even fatal. The Center for Biological Diversity filed a new petition to the FWS to protect the insects in 2021, and can only hope the butterflies will still be around by the time the agency weighs in.

“You’d think the Fish and Wildlife Service would want to err on the side of protecting species, and wouldn’t wait until they were on the brink,” says Greenwald. “But right now, they want incontrovertible proof that a species is in serious danger before listing—it’s cautious, but in the wrong direction.”