Is the Endangered Species Act a success?

Why the number of listed species that are no longer endangered is not a good measure of the Act’s success

The Republican-controlled Senate Environment and Public Works Committee held hearings a couple of weeks ago on “reforming” the Endangered Species Act.  (Coverage here and here, second link behind a paywall.)  An important theme of the hearing was arguments by Republican Senators that the ESA has failed because only a small fraction of species listed for protection under the Act have fully recovered such that they no longer require ESA-protection anymore.  (Species that have fully recovered include charismatic and famous species such as the bald eagle and peregrine falcon.)

In a comment to a former U.S. Fish and Wildlife Service director who testified at the hearing, Sen. James M. Inhofe (R-Okla.), repeated a point made by [Republican Wyoming Senator] Barrasso that of more than 1,600 species listed as threatened or endangered since the act’s inception, fewer than 50 have been removed.

That’s about 3 percent of the total, the chairman said. “As a doctor, if I admit 100 patients to the hospital and only three recover enough to be discharged, I would deserve to lose my medical license,” Inhofe said.

The problem with this comparison is the baseline that Senator Inhofe is using.  Many species are only listed for protection under the ESA when they are on the verge of extinction – in part because of litigation and political pressure from politicians like Senator Inhofe!  Moreover, the threats that many of these species face are not ones that are easily undone – if a species is on the edge of extinction because its habitat has mostly been converted to human use, listing it under the ESA generally simply stops further habitat conversion from occurring.  But if you want to recover the species, you need to actively undo the harm to the species’ habitat – something that again, most politicians would resist.  In fact, the problem is worse than that – habitat destruction takes time to cause the population of a species to drop, so even if you stop habitat destruction at a certain time, the population will generally continue to decline.  Finally, species that are left with tiny populations face a range of threats as a result of their small population size – inbreeding can cause birth defects and lower survival rates, isolated populations that disappear cannot be recolonized by other remaining populations, and a catastrophe can wipe out the last holdout population of a species.

Thus, if we wait until the last minute to list species for protection – and most of the threats we are addressing are not easily remedied – it should be no surprise that most species have not yet recovered.  Instead, the far better message would be how many species haven’t gone extinct while listed for protection under the ESA, and here the record is much better.

But that wouldn’t be a message that would advance an agenda to “reform” the ESA.

For some of the relevant academic literature here, see my article here (at pages 1334-1336), and my colleague Holly Doremus’s article here (subscription required).

Congress, Endangered Species Act, Republican Party