Testing a global standard for quantifying species recovery and assessing conservation impact

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a “Green List of Species” (now the IUCN Green Status of Species). A draft Green Status framework for assessing species’ progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species’ viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species’ recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard

Differential resilience of Amazonian otters along the Rio Negro in the aftermath of the 20th century international fur trade

Commercial hunting for the international trade in animal hides in the 20th century decimated many populations of aquatic wildlife in Amazonia. However, impacts varied significantly between different species and regions, depending upon hunting intensity, accessibility of habitat, and the inherent resilience of various species and their habitats. We investigated the differential responses of two Amazonian Mustelid species, the neotropical otter and giant otter, to commercial hunting pressure along the upper Rio Negro in Brazil, and examined historical factors that influenced spatial and temporal variation in commercial exploitation. We analyzed previously unanalyzed data from historical records of hide shipments to track changes in hide sales and prices for the two species in the late 20th century. We also gathered oral histories from older Baniwa people who had witnessed or participated in commercial otter hunting. These complimentary data sources reveal how intrinsic biological and social characteristics of the two otter species interacted with market forces and regional history. Whereas giant otter populations were driven to local or regional extinction during the late 20th century by commercial hunting, neotropical otters persisted. In recent decades, giant otter populations have returned to some parts of the upper Rio Negro, a development which local people welcome as part of a generalized recovery of the ecosystems in their territory as a result of the banning of animal pelt exports and indigenous land demarcation. This paper expands the scope of the field historical ecology and reflects on the role of local knowledge in biodiversity conservation