A simple, sufficient, and consistent method to score the status of threats and demography of imperiled species

Managers of large, complex wildlife conservation programs need information on the conservation status of each of many species to help strategically allocate limited resources. Oversimplifying status data, however, runs the risk of missing information essential to strategic allocation. Conservation status consists of two components, the status of threats a species faces and the species’ demographic status. Neither component alone is sufficient to characterize conservation status. Here we present a simple key for scoring threat and demographic changes for species using detailed information provided in free-form textual descriptions of conservation status. This key is easy to use (simple), captures the two components of conservation status without the cost of more detailed measures (sufficient), and can be applied by different personnel to any taxon (consistent). To evaluate the key’s utility, we performed two analyses. First, we scored the threat and demographic status of 37 species recently recommended for reclassification under the Endangered Species Act (ESA) and 15 control species, then compared our scores to two metrics used for decision-making and reports to Congress. Second, we scored the threat and demographic status of all non-plant ESA-listed species from Florida (54 spp.), and evaluated scoring repeatability for a subset of those. While the metrics reported by the U.S. Fish and Wildlife Service (FWS) are often consistent with our scores in the first analysis, the results highlight two problems with the oversimplified metrics. First, we show that both metrics can mask underlying demographic declines or threat increases; for example, ∼40% of species not recommended for reclassification had changes in threats or demography. Second, we show that neither metric is consistent with either threats or demography alone, but conflates the two. The second analysis illustrates how the scoring key can be applied to a substantial set of species to understand overall patterns of ESA implementation. The scoring repeatability analysis shows promise, but indicates thorough training will be needed to ensure consistency. We propose that large conservation programs adopt our simple scoring system for threats and demography. By doing so, program administrators will have better information to monitor program effectiveness and guide their decisions.

The least tern recovery effort has ameliorated threats to the population so that it is no longer endangered .

Background
The administration and monitoring of conservation programs are closely entwined. Administrators charged with conserving imperiled species must do so under budget and personnel constraints (Ferraro & Pattanayak, 2006). At the national and regional scales, these decision makers need to accurately evaluate hundreds or thousands of species based on their conservation status in order to allocate limited resources efficiently and objectively for the greatest conservation benefit (Bottrill et al., 2008; Joseph et al., 2008. At the same time, assessing the effectiveness of large conservation programs is challenging because of the taxonomic breadth of species and the variety of threats they face (see Purvis et al. [2000] for a summary of the many factors affecting extinction risk). Rarely do metrics capture necessary information concisely and consistently across all species. But such metrics are needed for wildlife managers to effectively allocate resources based on a species' current status.
Administrators of large conservation programs need a small number of highly informative and consistent metrics to accurately evaluate the conservation status of each species and conservation programs as a whole. Two fundamental components of conservation status are a species' demography (e.g., population size, range, and structure) and the threats it faces (Goble, 2009; Neel et al., 2012. Separating these factors is crucial because strategies for addressing threats and demographic status can differ greatly, e.g., population augmentation may improve demographic status while threats that will ultimately undo those gains continue unabated (National Marine Fisheries Service, 2010). Ideally, a small number of monitoring metrics would (a) capture the status or change of threats and demography independently, (b) be designed to apply consistently across all or most listed species, and (c) be easy to calculate given existing data, rather than requiring new and expensive monitoring programs. If such monitoring metrics are available, then the effectiveness of conservation programs can be evaluated in part (e.g., by geographic region) or in whole by analyzing the scores for all species under the program. For example, we could answer questions such as, What is the status of threats across all imperiled species covered by a conservation program? What proportion of imperiled species are declining or improving demographically? Are some regions doing better, on average, at addressing the threats to imperiled species than other regions?
The U.S. Fish and Wildlife Service (FWS) reports two possible conservation status metrics for species listed under the U.S. Endangered Species Act (ESA) in their Biennial Report to Congress. The first metric has changed over the years. Until 2010, FWS reported species status using categories including "declining", "improving", "stable", or "unknown." FWS stopped reporting each species' "status" after 2010 because they judged the conclusions were not scientifically rigorous enough (U.S. Fish and Wildlife Service, 2011). Today, FWS reports recommendations to reclassify a species' legal status that are based on fiveyear reviews of each species. Recommendations may include uplisting from threatened to endangered, downlisting an endangered species to threatened, delisting a species, or no status change (see Article S1 for an overview of the ESA listing lifecycle). The second reported metric is the Recovery Priority Number (RPN), which is used to prioritize recovery planning for ESAlisted species. RPNs are based on the immediacy of threats, recovery potential, taxonomic uniqueness, and conflict with human activities (U.S. Fish and Wildlife Service, 1983). Thus, both metrics contain some information about conservation status and both are used by FWS to allocate resources and make other decisions. But the question remains, are these reported metrics acceptable for monitoring the conservation status of species, or evaluating the effectiveness of the Endangered Species program based on the conservation status of many species?
There are three problems with using the metrics reported by FWS as conservation status metrics. First, a species listed as endangered can't be afforded more protection under the ESA, and neither Congress nor the public receives an early warning if an endangered species has continued to decline. In contrast to IUCN Red List categories that include "critically endangered" and "extinct in the wild" as options before extinction (Rodrigues et al., 2006), the ESA recognizes no classification between "endangered" and "extinct". Second, some changes in either threats or demography may not be sufficient to trigger reclassification, but are still sufficient to warrant the attention of managers during the monitoring and evaluation stages of the recovery and resource allocation process. FWS administrators will be hardpressed to make informed resource allocation decisions across the endangered species program without simple, sufficient, and consistent metrics of conservation status. Thus, on the first and second counts, recommendations for reclassification have significant shortcomings. Third, although used in conjunction with other information to guide resource allocation (U.S. Fish and Wildlife Service, 2013), RPNs are not sufficient for evaluating species status because they combine many factors, including some that are not conditional on changes of status (e.g., taxonomic uniqueness). Because the conservation status of individual species and groups of species is the ultimate metric by which conservation programs need to be evaluated, neither Congress nor the public can accurately evaluate the effectiveness of the ESA at recovering species using currently reported metrics. Furthermore, some species can "fall through the cracks" of conservation while recovery progress for other species goes unacknowledged. This is not to say that such species receive no attention; biologists and managers in the field may be aware of a species' plight. But regional or nationallevel administrators are much less likely to know of these issues, and can't make informed, highlevel resource allocation decisions, if unaware of the facts.