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

Endangered Species Conservation, Defenders of WIldlife, Washington, District of Columbia, United States of America
Department of Earth & Environmental Science, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
DOI
10.7287/peerj.preprints.1860v2
Subject Areas
Conservation Biology, Ecology, Science Policy
Keywords
Endangered Species Act, threats, demography, monitoring, conservation programs
Copyright
© 2016 Malcom et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Malcom JW, Webber WM, Li Y. 2016. A simple, sufficient, and consistent method to score the status of threats and demography of imperiled species. PeerJ Preprints 4:e1860v2

Abstract

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.

Author Comment

This is a revision that has been re-submitted to PeerJ for review. We addressed reviewers' concerns with text changes and by adding a second analysis, which focused on applying the scoring key to 54 ESA-listed species in Florida. The review history will be published with the paper, if/once accepted at PeerJ.

Supplemental Information

Article S1. The regulatory framework of listing, reclassification, and recovery

DOI: 10.7287/peerj.preprints.1860v2/supp-1

Information that might be given to FWS biologists as training for scoring threats and demography changes

DOI: 10.7287/peerj.preprints.1860v2/supp-2

Table S1. Cross-tabulation of taxonomic groups represented in our dataset

DOI: 10.7287/peerj.preprints.1860v2/supp-3

Table S2. Examples of text from Fish and Wildlife Service five-year reviews that resulted in different scores across the key in Table 1 of the main text

DOI: 10.7287/peerj.preprints.1860v2/supp-4