Beyond PVA: Why Recovery under the Endangered Species Act Is More than Population Viability

摘要

Recovery criteria under the Endangered Species Act are the objective, measurable targets for determining whether the recovery of listed species has been achieved. Existing criteria have been criticized as inconsistent and poorly supported. Recent proposals for improving those criteria have recommended framing them around population viability analysis (PVA) and setting criteria on the basis of extinction risk thresholds. Used in isolation, however, a PVA-centered approach is prone to limiting the scope of recovery, is too data intensive to be useful for most species, and risks misrepresenting normative recovery thresholds as objective. We recommend a framework based on the three Rs-the ecological principles of representation, resiliency, and redundancy-which makes use of multiple analytical approaches for setting recovery targets, including PVA when appropriate. We argue that the three Rs framework better fulfills the ESA's comprehensive recovery mandates for achieving geographic representation, ecosystem conservation, and threats abatement while overcoming data and budget limitations pervasive in recovery planning today.