Factors associated with preemptive conservation under the U.S. Endangered Species Act

Attributes of preemptive conservation efforts for species precluded from listing under the U.S. Endangered Species Act

Preemptive conservation efforts to reduce threats have been credited with precluding the need to list some imperiled species under the U.S. Endangered Species Act (ESA). Such efforts can result in outcomes where species are conserved and regulatory costs associated with ESA listing are avoided. Yet, the extent and type of conservation effort involved in achieving preclusion from listing are not well understood. We quantified the attributes of conservation efforts identified as important for 43 species whose preclusion from listing was attributed to conservation efforts, as described in U.S. Federal Register documents that report the decisions not to list. We considered 2 features of preemptive conservation: effort applied (measured as the number of conservation initiatives) and number of conservation partners involved. We also quantified the type and location of conservation actions. We found a mean of 4.3 initiatives (range 1-22) and 8.2 partners (range 1-31) documented per precluded species; both measures of conservation effort were significantly and positively associated with the species' range area and the proportion of private land across its range. The number of initiatives was also positively related to the number of threats affecting a species. Locations of conservation actions varied; more species had actions on public land than on private land (p = 0.003). Numbers of species with restorative actions (e.g., invasive species control) were similar to numbers with prohibitive actions. Our findings highlight relationships between species' context and preemptive conservation activities, providing a first cross-species analysis of conservation efforts for species that were precluded from listing under the ESA due to conservation.

A landmark environmental law looks ahead

In late December 1973, the United States enacted what some would come to call "the pitbull of environmental laws." In the 50 years since, the formidable regulatory teeth of the Endangered Species Act (ESA) have been credited with considerable successes, obliging agencies to draw upon the best available science to protect species and habitats. Yet human pressures continue to push the planet toward extinctions on a massive scale. With that prospect looming, and with scientific understanding ever changing, Science invited experts to discuss how the ESA has evolved and what its future might hold. -Brad Wible.