| Evaluating conservation status of populations has evolved over the past 40 years, providing practitioners with sophisticated tools to support risk assessment. Recent application of survey sampling techniques combined with stochastic population modeling for species like greater sage-grouse demonstrate the potential to evaluate populations at multiple spatial scales, incorporating important population processes. Population modeling facilitates risk assessments for only a small number of species for which sufficient data are available. The 2012 Forest Service Planning Rule, however, motivates examining conservation status of many populations in the absence of information to support complex analytics. How should biologists evaluate numerous species to meet regulatory demands and employ current science? Acceptable approaches must be repeatable, permit clear documentation, employ current science, and be accessible to agency staff. Published rules of thumb suggest specific abundance levels to highlight species at risk, but application of these thresholds has been challenged. Systematic evaluation of species distribution, population and habitat trend, limiting factors and threats, and life history, in a framework recognizing the key elements of population extinction, represents a tested approach. Thorough species assessments documenting ecological knowledge supporting the risk assessment communicate the science supporting the evaluation. |