Too Little, Too Late: Study Examines Why the Endangered Species Act Fails
Since its passage in 1973, the U.S. Endangered Species Act (ESA) has been the strongest law to stop species extinctions in the USA, and has served as a model of conservation policy to other nations.
Nevertheless, its success in helping species recuperate leaves rather a lot to be desired. Out of the multiple thousand species which were listed by the ESA previously 48 years, only 54 have recovered to the purpose where they not need protection. A latest study, published within the journal PLOS ONE, examines why so few species have recovered successfully.
The study — led by Erich Eberhard from Columbia University’s Department of Ecology, Evolution, and Environmental Biology, and co-authored by scholars at Princeton University — paints a grim picture. They find that almost all species will not be receiving protection until their populations are precariously small, dimming their prospects of recovery.
“We discover that small population sizes at time of listing, coupled with delayed protection and insufficient funding, proceed to undermine one in every of the world’s strongest laws for shielding biodiversity,” they write.
Out of the hundreds of species which were listed by the Endangered Species Act previously 48 years, only 54 have recovered to the purpose where they not need protection. Image: Eberhard et al. 2022
The findings are particularly newsworthy in light of the upcoming meeting of the United Nations Convention on Biological Diversity in December. The meeting goals to finalize a framework that can guide conservation efforts world wide through 2030. The planet currently faces accelerating rates of species extinction, with a projected lack of over 1 million species within the foreseeable future.
A persistent pattern
Small populations are more vulnerable to environmental and genetic threats, and thus more more likely to go extinct before conservation interventions can recuperate the species to a stable population size.
Evidence of species not receiving protection under the ESA until their populations have turn out to be very small was first reported in 1993, when a study found that species being listed for cover had, on average, just 1,075 remaining individuals for vertebrate species, 999 remaining individuals for invertebrate species, and 120 remaining individuals for plant species.
The brand new study repeats the 1993 study’s methodology to find out whether the US Fish and Wildlife Service has turn out to be more proactive throughout the roughly 30 years since attention was first drawn to the issue. The team also checked out trends in species’ “wait times” — the length of time between when a species is first identified as potentially needing protection and when it actually receives protected status under the ESA — and trends in funding for the listing and recovery of endangered species.

The Eastern cougar (Puma concolor couguar) was delisted from the Endangered Species Act in 2011, when it was officially declared extinct. It’s now believed to have gone extinct well before it received protection under the ESA. Photo: US Fish and Wildlife Service
Because it seems, species’ population sizes at time of listing didn’t significantly change between 1985-1991 and 1992-2020. The study also found that there are consistently long wait times before species receive protection, which further increases the chance of extinction to species with already small or rapidly declining populations.
Funding restrictions don’t help matters. While funding allocations declined between 2010 and 2020, the variety of species listed for cover increased by over 300% during that point. Consequently, the study found that funding for cover has dropped by nearly 50% per species since 1985.

The Red Knot (Calidris canutus rufa) was added to the threatened list in 2014 after populations had declined markedly for several a long time. Credit: Dan Liang/Princeton University
“Because the variety of imperiled species—and the threats that they face—multiply, the unlucky conclusion is that the U.S. Fish and Wildlife Service is being asked to do more with less resources,” said Eberhard.
Inadequate funding toward protecting threatened and endangered species has continued for a long time, the authors note, no matter which political parties are in power within the White House and Congress.
“Our study makes a very important point: It costs money to avoid wasting endangered species — money to discover which species are in trouble and deserve special attention, money to guard and restore habitats, money to eliminate other threats like harmful invasive species,” said co-author David Wilcove from Princeton University. “These endangered species can’t save themselves.”
Because the meeting of the Convention on Biological Diversity (COP15) draws near, the study authors hope that leaders within the U.S. and internationally will learn from these lessons to higher protect and conserve imperiled species across the globe.
“It’s a tragic testimony regarding the state of U.S. leadership on this issue as we go into the following round of international talks on global biodiversity,” said co-author Andrew Dobson from Princeton. “Nations have to commit more funds to saving
threatened species and biodiversity typically, which also serves as a hedge against climate change and will create many other societal advantages, including jobs.”
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