Measuring the success of the Endangered Species Act: examining progress toward recovery

Background/Question/Methods

The Endangered Species Act has safeguarded 99 percent of the 1,436 species under its care from extinction. A common critique of the law is that few species have been delisted due to recovery. Simply counting the number of species that have been delisted due to recovery is a non-informative metric because most species have not been listed long enough to reach their recovery goals. We attempted to answer the question, “Are species moving toward recovery at the predicted rate?”  We identified 110 endangered species that have advanced toward recovery since being protected under the Act. We defined “species” as species, subspecies or distinct population segment as identified by their recovery plans. We determined the population size for each species in as many years as possible with a particular emphasis on the time between listing and 2011. If range-wide population estimates were not available, we tracked alternative recovery indices. We extracted each species’ estimated time-to-recovery from their federal recovery plans. If a plan did not have a time-to-recovery estimate, we extracted its estimated time-to-downlisting from “endangered” to “threatened” status. We then compared the recovery goals to the most recent population size and trend.

Results/Conclusions

Ninety-nine of the 110 species we examined had recovery plans. Fifty-one plans included projected delisting dates. Forty-one of the deadlines (80 percent) occurred after 2011; thus those species had not missed their delisting deadline. Ten of the deadlines (20 percent) occurred by 2011, and nine of the ten species with deadlines by 2011 were delisted by 2011. Thus 90 percent of species with recovery timelines met them on time. To determine if this rate was biased by some unknown characteristic of the 51 species with timelines, we applied the same expectation — 20 percent recovered by 2011 — to the 59 species with no recovery timeline. The group met the deadline with 100 percent success: 12 of the 59 (20 percent) were delisted by 2011. Likelihood of delisting was correlated with the percent of the projected recovery period that had elapsed. The adequacy of recovery rates cannot be judged by the number of delisted species. It must be judged by the relationship between actual and projected recovery times. Many endangered species have increased to populations near or above their delisting goals. Many species will be delisted in the next decade, though many species will require decades to reach recovery goals.