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Friday's Findings - March 5 2021

February 22, 2021
Species Status Assessments to Support Endangered Species Decision Making

Date: March 5, 2021 from 2-2:30 p.m. eastern time


Conor McGowan, Assistant Unit Leader, Florida Cooperative Fish and Wildlife Research Unit

David Smith, Research Statistician (Biology), Eastern Ecological Science Center

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Call-in Option: 1 202-640-1187   

Conference ID: 387 327 121#

Black Rail in marsh.

Abstract: A series of critiques on the role of science in ESA decisions have called for improved consistency and transparency in species risk assessments and clear distinctions between science input and policy application. With these critiques in mind, we worked in close collaboration with the US Fish and Wildlife Service to devise a framework for species assessments that would provide Department of the Interior Decision makers with the science needed to support endangered species decision making such as classification decisions or recovery planning. The framework endeavors to develop a descriptive document with has 3 primary components:1) describes what we know about the species biology and ecological needs to thrive in its environment; 2) describes the current status of the species’ populations through data analysis and asking the question, does it have what it needs?; and 3) attempts to project the future status of the species’ populations through predictive modeling.  

The analyses of current and future status evaluate the species through the lenses of “representation,” “redundancy,” and “resiliency” of the populations – the “three Rs”. These are widely used and well-developed concepts in conservation biology, but the new SSA framework specifically defines each concept. 

The components of the “three Rs” are: 

  • Representation describes the ability of a species to adapt to changing environmental conditions, which is related to genetic and ecological diversity within the species’. 
  • Resiliency describes the ability of the species’ populations to withstand stochastic disturbance events, which is associated with population size, demographics, population growth rate, and habitat quality. 
  • Redundancy describes the ability of a species to withstand catastrophic events, which is related to the number, distribution, and resilience of populations. 

In the SSA’s reports, practitioners use measurable quantities related to the three Rs, such as abundance, distribution, population growth rate, heterozygosity, inbreeding depression, and changes in these quantities over time to make inference about the representation, redundancy, and resiliency for decision makers. One unifying commonality are the three core components and that all SSAs are focused on population viability analysis for the species. Population viability is an aging but well-developed scientific concept in conservation biology that focuses on predicting the future of a population and its extinction risk given uncertainties and stochasticities. In our presentation we highlight the case study of the Eastern Black Rail status assessment that demonstrates the interagency collaboration as well and the role that research, analysis and modeling played in the decision to list the species as threatened under the endangered species act.