Conservation triage or injurious neglect in endangered species recovery

Defining Populations and Predicting Future Suitable Niche Space in the Geographically Disjunct, Narrowly Endemic Leafy Prairie-Clover (Dalea foliosa; Fabaceae)

Conservation actions for rare species are often based on estimates of population size and number, which are challenging to capture in natural systems. Instead, many definitions of populations rely on arbitrarily defined distances between occurrences, which is not necessarily biologically meaningful despite having utility from a conservation management perspective. Here, we introduce a case study using the narrowly endemic and highly geographically disjunct leafy prairie-clover (Dalea foliosa), for which we use nuclear microsatellite loci to assess the current delimitations of populations and management units across its entire known range. We model future potential suitable niche space for the species to assess how currently defined populations could fare under predicted changes in climate over the next 50 years. Our results indicate that genetic variation within the species is extremely limited, particularly so in the distal portions of its range (Illinois and Alabama). Within the core of its range (Tennessee), genetic structure is not consistent with populations as currently defined. Our models indicate that predicted suitable niche space may only marginally overlap with the geology associated with this species (limestone glades and dolomite prairies) by 2070. Additional studies are needed to evaluate the extent to which populations are ecologically adapted to local environments and what role this could play in future translocation efforts.

Aligning the logics of inquiry and action to address the biodiversity crisis

Despite an abundance of research reaffirming biodiversity's importance to the health of the planet and society, species continue to go extinct at an alarming rate. Why has continued research on the value of biodiversity not had the intended effect and what can be done about it? We considered biodiversity loss as a public value failure and the result of a misalignment between the logic of inquiry (which guides scientists) and the logic of action (which guides practitioners). We drew lessons from our own research to propose the creation of a national biodiversity strategy designed to link the logic of inquiry with the logic of action and coordinate the production of actionable conservation science and informed conservation action.

Factors associated with preemptive conservation under the U.S. Endangered Species Act

In recent decades, there has been an increasing emphasis on proactive efforts to conserve species being considered for listing under the U.S. Endangered Species Act (ESA) before they are listed (i.e., preemptive conservation). These efforts, which depend on voluntary actions by public and private land managers across the species' range, aim to conserve species while avoiding regulatory costs associated with ESA listing. We collected data for a set of social, economic, environmental, and institutional factors that we hypothesized would influence voluntary decisions to promote or inhibit preemptive conservation of species under consideration for ESA listing. We used logistic regression to estimate the association of these factors with preemptive conservation outcomes based on data for a set of species that entered the ESA listing process and were either officially listed (n = 314) or preemptively conserved (n = 73) from 1996 to 2018. Factors significantly associated with precluded listing due to preemptive conservation included high baseline conservation status, low proportion of private land across the species' range, small total range size, exposure to specific types of threats, and species' range extending over several states. These results highlight strategies that can help improve conservation outcomes, such as allocating resources for imperiled species earlier in the listing process, addressing specific threats, and expanding incentives and coordination mechanisms for conservation on private lands.

Conservation implications of a mismatch between data availability and demographic impact

Cost-effective use of limited conservation resources requires understanding which data most contribute to alleviating biodiversity declines. Interventions might reasonably prioritise life-cycle transitions with the greatest influence on population dynamics, yet some contributing vital rates are particularly challenging to document. This risks managers making decisions without sufficient empirical coverage of the spatiotemporal variation experienced by the species. Here, we aimed to explore whether the number of studies contributing estimates for a given life-stage transition aligns with that transition's demographic impact on population growth rate, λ. We parameterised a matrix population model using meta-analysis of vital rates for the common eider (Somateria mollissima), an increasingly threatened yet comparatively data-rich species of seaduck, for which some life stages are particularly problematic to study. Female common eiders exhibit intermittent breeding, with some established breeders skipping one or more years between breeding attempts. Our meta-analysis yielded a breeding propensity of 0.72, which we incorporated into our model with a discrete and reversible 'nonbreeder' stage (to which surviving adults transition with a probability of 0.28). The transitions between breeding and nonbreeding states had twice the influence on λ than fertility (summed matrix-element elasticities of 24% and 11%, respectively), whereas almost 15 times as many studies document components of fertility than breeding propensity (n = 103 and n = 7, respectively). The implications of such mismatches are complex because the motivations for feasible on-the-ground conservation actions may be different from what is needed to reduce uncertainty in population projections. Our workflow could form an early part of the toolkit informing future investment of finite resources, to avoid repeated disconnects between data needs and availability thwarting evidence-led conservation.

The phenotypic costs of captivity

The breeding of threatened species in captivity for release is a central tool in conservation biology. Given gloomy predictions for biodiversity trends in the Anthropocene, captive breeding will play an increasingly important role in preventing future extinctions. Relative to the wild, captive environments drastically alter selection pressures on animals. Phenotypic change in captive animals in response to these altered selection pressures can incur fitness costs post-release, jeopardising their potential contribution to population recovery. We explore the ways in which captive environments can hinder the expression of wild phenotypes. We also stress that the phenotypes of captive-bred animals differ from their wild counterparts in multiple ways that remain poorly understood. We propose five new research questions relating to the impact of captive phenotypes on reintroduction biology. With better use of monitoring and experimental reintroductions, a more robust evidence base should help inform adaptive management and minimise the phenotypic costs of captivity, improving the success of animal reintroductions.

Is the Endangered Species Act living to its full potential? The reassessment of the conservation status and recovery of Macbridea alba Chapm. as a case study

Since 1988, the Cooperative Endangered Species Conservation Fund or “Section 6” fund facilitates partnerships between the U.S. Fish and Wildlife Service and state agencies that aim to provide data pertinent to the recovery of Endangered Species Act (ESA) protected species. Despite the success of these efforts, research for rare plants is chronically underfunded and many species experience long periods of research inactivity that hinders their conservation. One example is Macbridea alba Chapm. (white birds-in-a-nest, Lamiaceae, M. alba from hereon), a federally threatened and state endangered mint endemic to four counties within the Florida panhandle. The species is a candidate for delisting after 30 years of protection under the ESA, however a lack of up-to-date data associated with the species has continually challenged the implementation of effective conservation programs and prolonged the recovery process. The focus of this paper is to review the timeline of recovery goals for M. alba, present a summary of recent research findings (i.e., species distribution models, habitat associations, reproductive ecology), and identify achievements as well as persistent obstacles to recovery and delisting. Our research focused on 5 of 10 recovery actions listed in the recovery plan for M. alba. Our findings provide updated data and make novel contributions to the protection of M. alba that will prioritize and improve management efforts. Overall, our work highlights frequent barriers to the recovery and delisting of rare species, using an endemic plant species as a case-study. Importantly, we outline effective methods for the rapid assessment of at-risk plant species that due to enduring data gaps, face an uncertain future in listing and recovery. We hope our work provides a convincing case demonstrating the critical need for current and expanded ESA funding and encourages a diversity of individuals and institutions to participate in critical rare plant research to swiftly fill research gaps and expedite recovery of some of the rarest plant species across the United States.

Comparison of the gut microbiome and resistome in captive African and Asian elephants on the same diet

Elephants are endangered species and threatened with extinction. They are monogastric herbivorous, hindgut fermenters and their digestive strategy requires them to consume large amounts of low quality forage. The gut microbiome is important to their metabolism, immune regulation, and ecological adaptation. Our study investigated the structure and function of the gut microbiota as well as the antibiotic resistance genes (ARGs) in captive African and Asian elephants on the same diet. Results showed that captive African and Asian elephants had distinct gut bacterial composition. MetaStats analysis showed that the relative abundance of Spirochaetes (FDR = 0.00) and Verrucomicrobia (FDR = 0.01) at the phylum level as well as Spirochaetaceae (FDR = 0.01) and Akkermansiaceae (FDR = 0.02) at the family level varied between captive African and Asian elephants. Among the top ten functional subcategories at level 2 (57 seed pathway) of Kyoto Encyclopedia of Genes and Genomes (KEGG) database, the relative gene abundance of cellular community-prokaryotes, membrane transport, and carbohydrate metabolism in African elephants were significantly lower than those in Asian elephants (0.98 vs. 1.03%, FDR = 0.04; 1.25 vs. 1.43%, FDR = 0.03; 3.39 vs. 3.63%; FDR = 0.02). Among the top ten functional subcategories at level 2 (CAZy family) of CAZy database, MetaStats analysis showed that African elephants had higher relative gene abundance of Glycoside Hydrolases family 28 (GH 28) compared to Asian elephants (0.10 vs. 0.08%, FDR = 0.03). Regarding the antibiotic resistance genes carried by gut microbes, MetaStats analysis showed that African elephants had significantly higher relative abundance of vanO (FDR = 0.00), tetQ (FDR = 0.04), and efrA (FDR = 0.04) than Asian elephants encoding resistance for glycopeptide, tetracycline, and macrolide/rifamycin/fluoroquinolone antibiotic, respectively. In conclusion, captive African and Asian elephants on the same diet have distinct gut microbial communities. Our findings established the ground work for future research on improving gut health of captive elephants.

Recovery units under the Endangered Species Act should be used more widely

Recovering species is the main goal of the Endangered Species Act (ESA). In the face of limited conservation budgets, diverse tools are needed to efficiently recover species. Recovery units may be one such tool - designated portions of a species’ range that must be recovered individually before an entire species can be considered recovered. Recovery units allow for spatial flexibility in developing recovery goals and may be used in regulatory decisions such as ESA section 7 consultation. Despite the advantages, very little information exists on how recovery units have been developed and used. We mined available public data to determine the number and types of species for which recovery units have been designated; evaluated species and geographic characteristics associated with recovery unit designation; and examined how recovery units have been used in implementing the ESA, such as during consultation. We found 49 listed species had designated recovery units through December 2017, and that these species typically had relatively large ranges and were well-studied. We found taxonomic biases in recovery unit designation as well, with fish species being disproportionately likely to have recovery units and plants disproportionately less. These species were also more likely to have their recovery units considered and used in subsequent ESA implementation – a probability that decreased as time since unit designation passed. Improvements in recovery priority numbers among species with recovery units indicate that the theoretical benefits of this tool may have translated to improved status. These data indicate that recovery units could be applied to additional wide-ranging species to improve recovery under the ESA.

Hurdles to developing quantitative decision support for Endangered Species Act resource allocation

The U.S. Fish and Wildlife Service oversees the recovery of many species protected by the U.S. Endangered Species Act (ESA). Recent research suggests that a structured approach to allocating conservation resources could increase recovery outcomes for ESA listed species. Quantitative approaches to decision support can efficiently allocate limited financial resources and maximize desired outcomes. Yet, developing quantitative decision support under real-world constraints is challenging. Approaches that pair research teams and end-users are generally the most effective. However, co-development requires overcoming “hurdles” that can arise because of differences in the mental models of the co-development team. These include perceptions that: (1) scarce funds should be spent on action, not decision support; (2) quantitative approaches are only useful for simple decisions; (3) quantitative tools are inflexible and prescriptive black boxes; (4) available data are not good enough to support decisions; and (5) prioritization means admitting defeat. Here, we describe how we addressed these misperceptions during the development of a prototype resource allocation decision support tool for understanding trade-offs in U.S. endangered species recovery. We describe how acknowledging these hurdles and identifying solutions enabled us to progress with development. We believe that our experience can assist other applications of developing quantitative decision support for resource allocation.

How public values for threatened species are affected by conservation strategies

While the imminent extinction of many species is predicted, prevention is expensive, and decision-makers often have to prioritise funding. In democracies, it can be argued that conservation using public funds should be influenced by the values placed on threatened species by the public, and that community views should also affect the conservation management approaches adopted. We conducted on online survey with 2400 respondents from the general Australian public to determine 1) the relative values placed on a diverse set of 12 threatened Australian animal species and 2) whether those values changed with the approach proposed to conserve them. The survey included a contingent valuation and a choice experiment. Three notable findings emerged: 1) respondents were willing to pay $60/year on average for a species (95% confidence interval: $23 to $105) to avoid extinction in the next 20 years based on the contingent valuation, and $29 to $100 based on the choice experiment, 2) respondents were willing to pay to reduce the impact of feral animals on almost all presented threatened species, 3) for few species and respondents, WTP was lower when genetic modification to reduce inbreeding in the remaining population was proposed.

A comparison of monitoring designs to assess wildlife community parameters across spatial scales

Dedicated long-term monitoring at appropriate spatial and temporal scales is necessary to understand biodiversity losses and develop effective conservation plans. Wildlife monitoring is often achieved by obtaining data at a combination of spatial scales, ranging from local to broad, to understand the status, trends, and drivers of individual species or whole communities and their dynamics. However, limited resources for monitoring necessitates tradeoffs in the scope and scale of data collection. Careful consideration of the spatial and temporal allocation of finite sampling effort is crucial for monitoring programs that span multiple spatial scales. Here we evaluate the ability of five monitoring designs-stratified random, weighted effort, indicator unit, rotating panel, and split panel-to recover parameter values that describe the status (occupancy), trends (change in occupancy), and drivers (spatially varying covariate and an autologistic term) of wildlife communities at two spatial scales. Using an amphibian monitoring program that spans a network of US national parks as a motivating example, we conducted a simulation study for a regional community occupancy sampling program to compare the monitoring designs across varying levels of sampling effort (ranging from 10% to 50%). We found that the stratified random design outperformed the other designs for most parameters of interest at both scales and was thus generally preferable in balancing the estimation of status, trends, and drivers across scales. However, we found that other designs had improved performance in specific situations. For example, the rotating panel design performed best at estimating spatial drivers at a regional level. Thus, our results highlight the nuanced scenarios in which various design strategies may be preferred and offer guidance as to how managers can balance common tradeoffs in large-scale and long-term monitoring programs in terms of the specific knowledge gained. Monitoring designs that improve accuracy in parameter estimates are needed to guide conservation policy and management decisions in the face of broad-scale environmental challenges, but the preferred design is sensitive to the specific objectives of a monitoring program.

Population genomics of Sitka black-tailed deer supports invasive species management and ecological restoration on islands

Invasive mammals represent a critical threat to island biodiversity; eradications can result in ecological restoration yet may fail in the absence of key population parameters. Over-browsing by invasive Sitka black-tailed deer (Odocoileus hemionus sitkensis) is causing severe ecological and cultural impacts across the Haida Gwaii archipelago (Canada). Previous eradication attempts demonstrate forest regeneration upon deer removal, but reinvasion reverses conservation gains. Here we use restriction-site associated DNA sequencing (12,947 SNPs) to investigate connectivity and gene flow of invasive deer (n = 181) across 15 islands, revealing little structure throughout Haida Gwaii and identifying the large, central island of Moresby (>2600 km²) as the greatest source of migrants. As a result, the archipelago itself should be considered the primary eradication unit, with the exception of geographically isolated islands like SGang Gwaay. Thus, limiting eradications to isolated islands combined with controlled culling and enhanced biosecurity may be the most effective strategies for achieving ecological restoration goals.

Genomic data presented in this study provide clues about why previous attempts to eradicate the invasive Sitka black-tailed deer from the Haida Gwaii archipelago in Canada have been incomplete. The authors find substantial gene flow between islands, with the exception of the remote island of SGang Gwaay, which they argue is a viable option for near-term eradication efforts.

Threats to Neglected Biodiversity: Conservation Success Requires More Than Charisma

Our planet is home to an incredible array of species; however, relatively few studies have compared how anthropogenic threats impact taxonomic groups over time. Our objective was to identify temporal trends in threats facing the four most speciose phyla protected by the United States Endangered Species Act: angiosperms, arthropods, chordates, and mollusks. We determined presence or absence of threats for each species in these phyla by reviewing Final Rule listing decisions. For each phylum, we evaluated whether there was a linear, quadratic, or pseudo-threshold association between year of listing and the presence of 24 anthropogenic threats. We identified temporal trends for 80% of the 96 threat-phylum combinations. We classified threats as topmost (probability of being included in a species' listing decision peaking at ≥ 0.81) and escalating (probability of being included in a listing decision increasing by ≥ 0.81 between a species' first and most recent years of listing). Angiosperms, arthropods, and mollusks each had more topmost and escalating threats than chordates. Percentages of topmost threats were 42.9% (N = 21) for mollusks, 36.4% (N = 22) for angiosperms, and 33.3% (N = 21) for arthropods. Percentages of escalating threats were 22.7% (N = 22) for angiosperms and 14.3% (N = 21) for arthropods and mollusks. In contrast, percentages of topmost and escalating threats were only 4.2% (N = 24) for chordates, this one threat being climate change. Our research suggests potential conservation successes; some overutilization and pollution threats showed only gradually increasing or declining trends for certain phyla. We identified authorized take impacting angiosperms as the sole threat-phylum combination for which the threat had been consistently decreasing since the phylum's first year of listing. Conversely, species interactions, environmental stochasticity, and demographic stochasticity threats have seen drastic increases across all phyla; we suggest conservation efforts focus on these areas of increasing concern. We also recommend that resources be allocated to phyla with numerous topmost and escalating threats, not just to chordates.

An integrative synthesis to global amphibian conservation priorities

Human activities are driving many species to the brink of extinction, and the current distribution of protected areas only weakly alleviates pressure on threatened species. This discrepancy reflects the presence of protected areas on lands available instead of the ecological, evolutionary, or conservation values of species present. Habitat loss consequently continues to impact threatened species, as illustrated by geographic patterns of biodiversity loss for amphibians. Given the need to better align the boundaries of protected areas with at-risk biodiversity, we assessed the importance of various factors for identifying global and biome-level conservation priority areas, specifically for amphibians. We identified, mapped, and ranked areas of critical conservation importance for all amphibian species on earth using a new integrative tool that scores the urgency of conserving each species and location based on a combination of species characteristics and ecoregion-level human impacts. Our integrative approach is novel in that it accounts for likely threats to Data Deficient species, considers the irreplaceability of unique species that are phylogenetically isolated, and addresses the localized conservation implications of species endemicity and projected future human impacts to an ecoregion. For comparison, we also mapped and ranked amphibian biodiversity using species richness and an Evolutionarily Distinct and Globally Endangered (EDGE) score proxy. Our integrative approach predicted key regions for amphibian conservation that were not apparent when using a simple species richness or EDGE score proxy-based approach. Furthermore, by scaling conservation priority scores relative to biome, we identified several temperate and xeric regions of crucial yet overlooked conservation importance for amphibians. Until global amphibian diversity is thoroughly catalogued, we recommend using our integrative scoring approach to set geographic priorities for amphibian habitat protection, while acknowledging that this approach may be complemented by others (e.g., EDGE scores). Our study provides an avenue for avoiding common pitfalls of more simplistic species richness-based approaches for conservation planning, and can be used to improve the future design of protected areas.

Gaps in global wildlife trade monitoring leave amphibians vulnerable

As the biodiversity crisis continues, we must redouble efforts to understand and curb pressures pushing species closer to extinction. One major driver is the unsustainable trade of wildlife. Trade in internationally regulated species gains the most research attention, but this only accounts for a minority of traded species and we risk failing to appreciate the scale and impacts of unregulated legal trade. Despite being legal, trade puts pressure on wild species via direct collection, introduced pathogens, and invasive species. Smaller species-rich vertebrates, such as reptiles, fish, and amphibians, may be particularly vulnerable to trading because of gaps in regulations, small distributions, and demand of novel species. Here, we combine data from five sources: online web searches in six languages, Convention on International Trade in Endangered Species (CITES) trade database, Law Enforcement Management Information System (LEMIS) trade inventory, IUCN assessments, and a recent literature review, to characterise the global trade in amphibians, and also map use by purpose including meat, pets, medicinal, and for research. We show that 1215 species are being traded (17% of amphibian species), almost three times previous recorded numbers, 345 are threatened, and 100 Data Deficient or unassessed. Traded species origin hotspots include South America, China, and Central Africa; sources indicate 42% of amphibians are taken from the wild. Newly described species can be rapidly traded (mean time lag of 6.5 years), including threatened and unassessed species. The scale and limited regulation of the amphibian trade, paired with the triptych of connected pressures (collection, pathogens, invasive species), warrants a re-examination of the wildlife trade status quo, application of the precautionary principle in regard to wildlife trade, and a renewed push to achieve global biodiversity goals.

In the last few decades, exotic pets have become much more common. In the UK in 2008, reptiles and amphibians were more popular than dogs, with over eight million in captivity. But while almost all pet cats and dogs are born and bred in captivity, exotic pets are often taken from the wild, putting species and their habitats at risk.

An international trade agreement called the Convention on International Trade in Endangered Species (CITES) strives to prevent unsustainable animal trade. But to get CITES protection, species depend on data showing that wildlife trade threatens their survival. In addition, their range countries need to first propose them to be listed. For most wild animal species, there are no data on population size or population decline. In the case of amphibians, CITES regulates the trade of just 2.5% of species. This leaves the rest with no protection from overarching international trade regulations. To protect these animals, researchers need to find out which species are in trade, where they are coming from, and how many are already threatened.

To address this, Hughes, Marshall and Strine combined data from five sources, including official CITES trade records, recent research and an online search for amphibian sales in six languages. The data showed evidence of trade in at least 1,215 amphibian species, representing 17% of all amphibians. The figure is three times higher than previous estimates. Of the species in trade, more than one in five is vulnerable to extinction, endangered, or critically endangered. For a further 100 of the traded species, data on population were unavailable. Moreover, analysis of the origins of traded individuals showed that around 42% came from the wild. Tropical parts of the world had the highest number of species in trade, but the data showed exchanges happening across the globe.

Unsustainable wildlife trade can have devastating consequences for wild animals. It has already driven at least 21 reptile species to extinction, and data of amphibian species are unknown. To prevent further species going extinct, legal wildlife trade should follow the precautionary principle when it comes to wildlife trade. Rather than allowing people to trade a species until CITES regulates it, a blanket ban should come into force for species that have not been assessed or are threatened. Trade would be able to resume for a species only when assessments show that it would not cause major population decline, or secure, captive breeding facilities can be guaranteed.

The Promise of Genetics and Genomics for Improving Invasive Mammal Management on Islands

Invasive species are major contributors to global biodiversity decline. Invasive mammalian species (IMS), in particular, have profound negative effects in island systems that contain disproportionally high levels of species richness and endemism. The eradication and control of IMS have become important conservation tools for managing species invasions on islands, yet these management operations are often subject to failure due to knowledge gaps surrounding species- and system-specific characteristics, including invasion pathways and contemporary migration patterns. Here, we synthesize the literature on ways in which genetic and genomic tools have effectively informed IMS management on islands, specifically associated with the development and modification of biosecurity protocols, and the design and implementation of eradication and control programs. In spite of their demonstrated utility, we then explore the challenges that are preventing genetics and genomics from being implemented more frequently in IMS management operations from both academic and non-academic perspectives, and suggest possible solutions for breaking down these barriers. Finally, we discuss the potential application of genome editing to the future management of invasive species on islands, including the current state of the field and why islands may be effective targets for this emerging technology.

Reallocating budgets among ongoing and emerging conservation projects

Conserving biodiversity and combating ecological hazards require cost-effective allocation of limited resources among potential management projects. Project priorities, however, can change over time as underlying social-ecological systems progress, novel priorities emerge, and management capabilities evolve. Thus, reallocation of ongoing investments in response to shifting priorities could improve management outcomes and address urgent demands, especially when additional funding is not available immediately. Resource reallocation, however, could incur transaction costs, require additional monitoring and reassessment, and be constrained by ongoing project commitments. Such complexities may prevent managers from considering potentially beneficial reallocation strategies, reducing long-term effectiveness. We propose an iterative project prioritization approach, based on marginal return-on-investment estimation and portfolio optimization, that guides resource reallocation among ongoing and new projects. Using simulation experiments in 2 case studies, we explored how this approach can improve efficacy under varying reallocation constraints, frequencies, costs, and rates of project portfolio change. Periodic budget reallocation could enhance the management of stochastically emerging invasive weeds in Australia and thus reduce the overall risk by up to 50% compared with a static budget. Reallocation frequency and the rate of new weed incursion synergistically increased the conservation gains achieved by allowing unconstrained reallocation. Conversely, budget reallocation would not improve the International Union for Conservation of Nature conservation status of threatened Australian birds due to slow rates of transition among conservation states; extinction risk could increase if portfolio reassessment is costly. Although other project prioritization studies may recommend periodic reassessment and reallocation, our findings revealed conditions when reallocation is valuable and demonstrated a structured approach that can help conservation agencies schedule and implement iterative budget-allocation decisions cost-effectively.

Benchmark for the ESA: Having a Backbone Is Good for Recovery

To forestall the current rate of global extinction, we need to identify strategies that successfully recover species. In the last decade, the recovery record for the United States Endangered Species Act (ESA) has improved. Our aim was to review federal delisting documents for recovered species and quantify patterns in taxonomy, history of threats, policy, funding and actions that are associated with species recovery. In comparison to species still listed, the average recovered species was a vertebrate, had been listed longer under the ESA, was exposed to a lower number of threats at the time of listing, and received relatively higher levels of funding. Based on our review, we suggest the following strategies to improve species recovery: provide more time for ESA protection, allocate more funding for recovery, maintain environmental regulations that facilitate recovery, establish more private landowner agreements, and increase the area of protected lands.

Anthropogenic interferences lead to gut microbiome dysbiosis in Asian elephants and may alter adaptation processes to surrounding environments

Human activities interfere with wild animals and lead to the loss of many animal populations. Therefore, efforts have been made to understand how wildlife can rebound from anthropogenic disturbances. An essential mechanism to adapt to environmental and social changes is the fluctuations in the host gut microbiome. Here we give a comprehensive description of anthropogenically induced microbiome alterations in Asian elephants (n = 30). We detected gut microbial changes due to overseas translocation, captivity and deworming. We found that microbes belonging to Planococcaceae had the highest contribution in the microbiome alterations after translocation, while Clostridiaceae, Spirochaetaceae and Bacteroidia were the most affected after captivity. However, deworming significantly changed the abundance of Flavobacteriaceae, Sphingobacteriaceae, Xanthomonadaceae, Weeksellaceae and Burkholderiaceae. These findings may provide fundamental ideas to help guide the preservation tactics and probiotic replacement therapies of a dysbiosed gut microbiome in Asian elephants. More generally, these results show the severity of anthropogenic activities at the level of gut microbiome, altering the adaptation processes to new environments and the subsequent capability to maintain normal physiological processes in animals.

Endemic Population Response to Increasingly Severe Fire: A Cascade of Endangerment for the Mt. Graham Red Squirrel

Drought, past fire suppression, insect invasion, and high-severity fire represent a disturbance cascade characteristic of forests in the western United States. The result is altered forest ecosystems diminished in their function and capacity to support biodiversity. Small habitat specialists are particularly vulnerable to the impacts of disturbances because of their limited movement capacity and high site fidelity. Research suggests that small mammals suffer limited direct mortality from fire but are increasingly vulnerable to local extirpation because of secondary impacts that include habitat loss and reduced food availability, survival, and reproduction. We examine the direct and secondary impacts of increasingly severe fire events on the endangered Mt. Graham red squirrel—a model system to demonstrate how disturbances can threaten the persistence of range-limited species. We document survival, space use, and displacement prior to and following fires and discuss implications for conservation. We suggest that management plans address future threats, including disturbance-related habitat loss.

Ten bridges on the road to recovering Canada’s endangered species

Wildlife is declining around the world. Many developed nations have enacted legislation on endangered species protection and provide funding for wildlife recovery. Protecting endangered species is also supported by the public and judiciary. Yet, despite what appear as enabling conditions, wild species continue to decline. Our paper explores pathways to endangered species recovery by analyzing the barriers that have been identified in Canada, the United States, and Australia. We summarize these findings based on Canada’s Species at Risk Conservation Cycle (assessment, protection, recovery planning, implementation, and monitoring and evaluation) and then identify 10 “bridges” that could help overcome these barriers and bend our current trajectory of wildlife loss to recovery. These bridges include ecosystem approaches to recovery, building capacity for community co-governance, linking wildlife recovery to ecosystem services, and improving our storytelling about the loss and recovery of wildlife. The focus of our conclusions is the Canadian setting, but our findings can be applied in other national and subnational settings to reverse the decline of wildlife and halt extinction.

The dominating influence of efficacy above management strategy in the long-term success of alien plant clearing programmes

Conservation managers are required to make decisions in complex and uncertain contexts. To strengthen the robustness of conservation decisions, several approaches have been proposed to facilitate stakeholder engagement in the setting of conservation objectives and priority actions. While such processes have led to the formulation of several invasive alien plant management strategies to achieve specific objectives, the long-term consequences and trade-offs inherent in these strategies have not been tested. The performance of five of these strategies over 50 years was tested in the protected area context using empirical data from Table Mountain National Park, South Africa. A simulation model based on data for invasive Acacia species in a fire-driven ecosystem, focused on the interaction between strategy performance and clearing efficacy in achieving a management goal or reducing Acacia density to below 1 plant per hectare. At near perfect levels of clearing efficacy, all strategies converged towards reaching the management goal, while at lower efficacy levels the strategies diverged in their ability to achieve desired outcomes. Despite working across the largest area, strategies that focussed on clearing low density invasions, maintained the least area in a maintenance state over time. In contrast, strategies that focussed on a mix of post-fire, low density areas and high altitude areas cleared less area annually, but maintained a much larger area in a maintenance state. At higher levels of efficacy, strategies that return to previously worked areas were more successful than a post-fire strategy. Strategies that focused solely on securing water, performed poorly in maintaining low overall density of aliens. However, the influence of efficacy was significant and substantial and a much larger difference in area reaching the management goal was achieved by varying efficacy than varying strategy. As such, improving quality of work and implementation will have a far greater effect than which areas are prioritized or how this prioritization is done. While acacias are likely to persist in the long-term, improving work quality coupled with correct strategy selection will ensure continued gains in the area under maintenance and improved return on investment over time.

Half of resources in threatened species conservation plans are allocated to research and monitoring

Funds to combat biodiversity loss are insufficient, requiring conservation managers to make trade-offs between costs for actions to avoid further loss and costs for research and monitoring to guide effective actions. Using species' management plans for 2328 listed species from three countries we show that 50% of species' proposed recovery plan budgets are allocated to research and monitoring. The proportion of budgets allocated to research and monitoring vary among jurisdictions and taxa, but overall, species with higher proportions of budgets allocated to research and monitoring have poorer recovery outcomes. The proportion allocated to research and monitoring is lower for more recent recovery plans, but for some species, plans have allocated the majority of funds to information gathering for decades. We provide recommendations for careful examination of the value of collecting new information in recovery planning to ensure that conservation programs emphasize action or research and monitoring that directly informs action.

Big trouble for little fish: identifying Australian freshwater fishes in imminent risk of extinction

Globally, freshwater fishes are declining at an alarming rate. Despite much evidence of catastrophic declines, few Australian species are listed as threatened under national legislation. We aim to help redress this by identifying the Australian freshwater fishes that are in the most immediate risk of extinction. For 22 freshwater fishes (identified as highly threatened by experts), we used structured expert elicitation to estimate the probability of extinction in the next ~20 years, and to identify key threats and priority management needs. All but one of the 22 species are small (<150mm total length), 12 have been formally described only in the last decade, with seven awaiting description. Over 90% of these species were assessed to have a >50% probability of extinction in the next ~20 years. Collectively, the biggest factor contributing to the likelihood of extinction of the freshwater fishes considered is that they occur in small (distributions ≤44km2), geographically isolated populations, and are threatened by a mix of processes (particularly alien fishes and climate change). Nineteen of these species are unlisted on national legislation, so legislative drivers for recovery actions are largely absent. Research has provided strong direction on how to manage ~35% of known threats to the species considered, and, of these, ~36% of threats have some management underway (although virtually none are at the stage where intervention is no longer required). Increased resourcing, management intervention and social attitudinal change is urgently needed to avert the impending extinction of Australia’s most imperilled freshwater fishes.

Site-selection bias and apparent population declines in long-term studies

Detecting population declines is a critical task for conservation biology. Logistical difficulties and the spatiotemporal variability of populations make estimation of population declines difficult. For statistical reasons, estimates of population decline may be biased when study sites are chosen based on abundance of the focal species. In this situation, apparent population declines are likely to be detected even if there is no decline. This site-selection bias is mentioned in the literature but is not well known. We used simulations and real population data to examine the effects of site-selection biases on inferences about population trends. We used a left-censoring method to detect population-size patterns consistent with site-selection bias. The site-selection bias is an important consideration for conservation biologists, and we offer suggestions for minimizing or mitigating it in study design and analysis. Article impact statement: Estimates of population declines are biased if studies begin in large populations, and time-series data show a signature of such an effect.

Modeling trade-offs across carbon sequestration, biodiversity conservation, and equity in the distribution of global REDD+ funds

The program on Reducing Emissions from Deforestation and Forest Degradation (REDD+) is one of the major attempts to tackle climate change mitigation in developing countries. REDD+ seeks to provide result-based incentives to promote emission reductions and increase carbon sinks in forest land while promoting other cobenefits, such as the conservation of biodiversity. We model different scenarios of international REDD+ funds distribution toward potential recipient countries using 2 carbon emission reduction targets (20% and 50% compared to the baseline scenario, i.e., deforestation and forest degradation without REDD+) by 2030. The model combines the prioritization of environmental outcomes in terms of carbon sequestration and biodiversity conservation and social equity, accounting for the equitable distribution of international REDD+ funds. Results highlight the synergy between carbon sequestration and biodiversity conservation under alternative fund allocation criteria, especially for scenarios of low carbon emission reduction. Trade-offs increase when distributional equity is considered as an additional criterion, especially under higher equity requirements. The analysis helps to better understand the inherent trade-offs between enhancing distributional equity and meeting environmental targets under alternative REDD+ fund allocation options.

Novel data show expert wildlife agencies are important to endangered species protection

To protect biodiversity, conservation laws should be evaluated and improved using data. We provide a comprehensive assessment of how a key provision of the U.S. Endangered Species Act (ESA) is implemented: consultation to ensure federal actions do not jeopardize the existence of listed species. Data from all 24,893 consultations recorded by the National Marine Fisheries Service (NMFS) from 2000-2017 show federal agencies and NMFS frequently agreed (79%) on how federal actions would affect listed species. In cases of disagreement, agencies most often (71%) underestimated effects relative to the conclusions of species experts at NMFS. Such instances can have deleterious consequences for imperiled species. In 22 consultations covering 14 species, agencies concluded that an action would not harm species while NMFS determined the action would jeopardize species' existence. These results affirm the importance of the role of NMFS in preventing federal actions from jeopardizing listed species. Excluding expert agencies from consultation compromises biodiversity conservation, but we identify approaches that improve consultation efficiency without sacrificing species protections.

Structured Decision-Making Incorporates Stakeholder Values into Management Decisions Thereby Fulfilling Moral and Legal Obligations to Conserve Species

More than 1,500 species of plants and animals in the United States are listed as threatened or endangered under the Endangered Species Act and habitat destruction is the leading cause of population decline. However, developing conservation plans that are consistent with a diversity of stakeholder (e.g., states, tribes, private landowners) values is difficult. Adaptive management and structured decision-making are frameworks that resource managers can use to integrate diverse and conflicting stakeholder value systems into species recovery planning. Within this framework difficult decisions are deconstructed into the three basic components: explicit, quantifiable objectives that represent stakeholder values; mathematical models used to predict the effect of management decisions on the outcome of objectives; and management alternatives or actions. We use Bull Trout Salvelinus confluentus, a species listed in 1999 as threatened pursuant to the Endangered Species Act, as an example of how structured decision-making transparently incorporates stakeholder values and biological information into conservation planning and the decision process. Three moral philosophies—consequentialism, deontology, and virtue theory—suggest that structured decision-making is a justified method that can guide natural resource decisions in the future, consistent with United States Congress' mandate, and will honor society's obligation to recover Endangered Species Act listed species and their habitats. Natural sciences offer a biological basis for predicting the outcomes of decisions. Additionally, an understanding of how to integrate humanities into scientifically defensible conservation planning is helpful in providing the foundation for lasting and effective species conservation.

Foundation Species, Non-trophic Interactions, and the Value of Being Common

Foundation species define ecosystems, control the biological diversity of associated species, modulate critical ecosystem processes, and often have important cultural values and resonance. This review summarizes current understanding of the characteristics and traits of foundation species and how to distinguish them from other “important” species in ecological systems (e.g., keystone, dominant, and core species); illustrates how analysis of the structure and function of ecological networks can be improved and enriched by explicit incorporation of foundation species and their non-trophic interactions; discusses the importance of pro-active identification and management of foundation species as a cost-effective and efficient method of sustaining valuable ecosystem processes and services and securing populations of associated rare, threatened, or endangered species; and suggests broader engagement of citizen-scientists and non-specialists in the identification and study of foundation species and their biological and cultural values.

Ecological Function Analysis: Incorporating Species Roles into Conservation

Effective conservation strategies must ensure that species remain not just extant, but able to maintain key roles in species interactions and in the maintenance of communities and ecosystems. Such ecological functions, however, have not been well incorporated into management or policy. We present a framework for quantifying ecological function that is complementary to population viability analysis (PVA) and that allows function to be integrated into strategic planning processes. Ecological function analysis (EFA) focuses on preventing secondary extinctions and maintaining ecosystem structure, biogeochemical processes, and resiliency. EFA can use a range of modeling approaches and, because most species interactions are relatively weak, EFA needs to be performed for relatively few species or functions, making it a realistic way to improve conservation management.