The IUCN Green List of Species (Akçakaya et al., 2018, Conservation Biology, 32, 1128–1138) is a new tool for measuring species recovery and conservation success. A stepwise process assesses a species’ status across its indigenous range to produce a score (0–100%) against full recovery. This score is estimated for the past, present and future, with and without conservation, and produces four metrics: conservation legacy (impacts of past conservation efforts), conservation dependence (necessity of continued action), conservation gain (from actions in the next 10 years or three generations), and recovery potential (maximum plausible recovery in 100 years). The IUCN Species Conservation Success Task Force is testing the assessment methods before formal adoption planned for 2020.
We were interested to know how the proposed Green List of Species could be used to monitor the impacts of conservation agencies and donors. During June–August 2019 we worked with taxonomic experts to conduct preliminary assessments for 15 species that are, or will be, the focus of projects funded by the National Geographic Society. Test assessments of mammals (African manatee Trichechus senegalensis, northern sportive lemur Lepilemur septentrionalis, Sumatran rhino Dicerorhinus sumatrensis), birds (African penguin Spheniscus demersus, Alagoas antwren Myrmotherula snowi, Fatu Hiva monarch Pomarea whitneyi), amphibians (dusky gopher frog Lithobates sevosus, Houston toad Anaxyrus houstonensis, mountain chicken Leptodactylus fallax), fishes (estuarine pipefish Syngnathus watermeyeri, largetooth sawfish Pristis pristis), insects (Patagonian bumblebee Bombus dahlbomii, Poweshiek skipperling Oarisma poweshiek) and dipterocarp trees (Anisoptera reticulata, Vatica maritima) provided insights into the effectiveness of the tool across taxa, regions and biomes.
Preliminary Green List of Species metrics were produced for all 15 species, even those with limited data on abundance and distribution, and assessors made recommendations to improve assessment materials. Assessors found the tool useful and felt it addresses the identified need (Mallon & Jackson, 2017, Oryx, 51, 605–609) to demonstrate conservation successes and incentivize donors.
The highest conservation legacy scores were for birds (African penguin, Fata Hivu monarch), for whom failure to conserve habitats would have resulted in possible extinction. Eleven species are reliant on conservation to maintain their status (conservation dependence > 0%), of which eight (African manatee, northern sportive lemur, Sumatran rhino, dusky gopher frog, Houston toad, mountain chicken, largetooth sawfish, Poweshiek skipperling) would probably become extirpated in the wild if conservation actions were halted.
Conservation gains are expected for eight species, with planned field projects likely to help produce the largest improvements in the mountain chicken and northern sportive lemur. Seven species had 0% conservation gain, suggesting their status may not improve in 10 years or three generations, even with conservation. This does not mean funding is misplaced (all seven species had a legacy or dependence score ≥ 20%, demonstrating the importance of conservation). Rather, low conservation gains reflected challenges associated with conserving species that have small populations surviving in pockets of former range (e.g. Sumatran rhino, Poweshiek skipperling), face multiple threats across wide ranges (e.g. African manatee), or reproduce slowly (trees). Finally, although it may not be observed in the short term, all 15 species have long-term recovery potential and therefore conservation could improve their status.
We conclude that the Green List of Species can be used on diverse plant and animal species, although further testing will provide greater insights into its applicability across taxa. Conservation agencies and donors such as the National Geographic Society can use the conservation dependence and conservation gain metrics to monitor the impact of certain types of projects, as long as they operate at large enough temporal and spatial scales to address key threats. Regardless of project scale, the tool could help value and incentivize conservation and could assist in developing a common vision for range-wide species recovery.
Our insights have been shared with the IUCN Species Conservation Success Task Force and will be used to enhance the Green List of Species standard and guidance materials. We are indebted to the 26 people who helped with the assessments; they will co-author scientific papers to provide further peer review of the methods. The testing process enhanced our understanding of the value and uses of the IUCN Green List of Species and will ensure the tool is adapted and improved to be relevant and applicable to as many species as possible.
