Endangered Species Act Research Articles

Multispecies approaches to status assessments in support of endangered species classifications

AbstractMultispecies risk assessments have developed within many international conservation programs, reflecting a widespread need for efficiency. Under the United States Endangered Species Act (ESA), multispecies assessments ultimately lead to species‐level listing decisions. Although this approach provides opportunities for improved efficiency, it also risks overwhelming or biasing the assessment process and would benefit from clear guidance for practitioners. We reviewed multispecies assessments conducted between 1993 and 2019 for ESA listing decisions to identify the ecological basis for combining species, the assessment approach used, and the policy factors influencing their efficacy. We identified 42 cases covering 359 species. Most assessments (81%) included two to five species, although the maximum was 82. A common theme involved grouping narrow endemics or habitat specialists based on taxonomic relatedness, similar distributions, and common threats to persistence. All assessments included a combined threats analysis, but few employed a common species' response model or expert elicitation process. Although ESA risk assessments are distinct from policy decisions, most assessments (50%) supported decisions that all species warranted endangered status. Available guidance has generally emphasized ecological similarity as the key attribute leading to successful multispecies assessments. The challenge with consistently selecting species based on qualitative proxies such as common distributions or threats to persistence is that ecological patterns and processes are scale dependent. Focusing instead on the assessment methods and their potential for bias and increased efficiency may provide a stronger basis for developing consistent and transparent guidance.

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.

Thermal Preference and Tolerance of the Black Abalone Haliotis cracherodii (Leach 1814) (Gastropoda: Prosobranchia)

Haliotis cracherodii is the only abalone species listed as critically endangered (IUCN Red List) and protected under the Endangered Species Act (ESA) since 2009. The population started decreasing in the mid-1980s throughout its biogeographical range due to the “withering syndrome” disease. The objective of this study was to evaluate the thermoregulation of the black abalone, establishing its preferred temperature, locomotion displacement, and critical thermal maximum (CTMax). The preferred temperature (PT) was 13.8 °C. The theoretical temperature for optimal growth of the black abalone was 14.3 °C. The locomotion displacement in the gradient had an interval of 137 to 83 cm h–1. CTMax was evaluated, the first abalone detached from the substrate at a temperature of 25.4 °C and the last one at 31 °C; CTMax of 50% was calculated at 29.7 °C. These data will allow us to maintain and condition the black abalone in captivity with the final goal of producing seed for the restoration of disease-impacted populations on the Baja California Peninsula. ENSO events may also affect the survival of black abalone. We extrapolated the Thermal Safety Margin (TSM) = (28.8 – 18.31 °C) = 10.49 °C in weak ENSOs, but in stronger ENSO the TSM value diminishes to 3.17 °C suggesting that black abalone may be vulnerable to climate change.

Public involvement, trust, and support for endangered species programs

AbstractThe success of wildlife conservation, including endangered species programs, often depends on public support. We examined public support for threatened and endangered species management in New York State (NYS) and the factors influencing support. We surveyed 3 stakeholder groups important to the NYS Department of Environmental Conservation (DEC) in 2017: residents of upstate New York, hunters, and anglers. We measured support in 2 ways: (1) the importance people placed on the government protecting threatened and endangered species in NYS, and (2) satisfaction with DEC's efforts to protect these species. Using structural equation modeling, we examined factors hypothesized to increase public support: trust in the agency, adequate public involvement in decision‐making, and the perceived importance of program outcomes. For hunters and anglers, we found that perceived adequacy of public involvement was positively related to program satisfaction, but only because it fostered perceptions of good management decisions. Although adequacy of public involvement also contributed to program satisfaction for upstate residents, we found no evidence that they were more satisfied because they thought public involvement led to better decisions. For all 3 groups the perception of adequate public involvement was directly related to trust in the agency, which in turn was positively related to belief in agency competency to protect threatened and endangered species. Our results suggest that wildlife managers can enhance public satisfaction with decisions and programs through public involvement, communication about how public involvement contributes to decisions, and building trust in the agency.

Cumulative effects of piscivorous colonial waterbirds on juvenile salmonids: A multi predator-prey species evaluation.

We investigated the cumulative effects of predation by piscivorous colonial waterbirds on the survival of multiple salmonid (Oncorhynchus spp.) populations listed under the U.S. Endangered Species Act (ESA) and determined what proportion of all sources of fish mortality (1 –survival) were due to birds in the Columbia River basin, USA. Anadromous juvenile salmonids (smolts) were exposed to predation by Caspian terns (Hydroprogne caspia), double-crested cormorants (Nannopterum auritum), California gulls (Larus californicus), and ring-billed gulls (L. delawarensis), birds known to consume both live and dead fish. Avian consumption and survival probabilities (proportion of available fish consumed or alive) were estimated for steelhead trout (O. mykiss), yearling Chinook salmon (O. tshawytscha), sub-yearling Chinook salmon, and sockeye salmon (O. nerka) during out-migration from the lower Snake River to the Pacific Ocean during an 11-year study period (2008–2018). Results indicated that probabilities of avian consumption varied greatly across salmonid populations, bird species, colony location, river reach, and year. Cumulative consumption probabilities (consumption by birds from all colonies combined) were consistently the highest for steelhead, with annual estimates ranging from 0.22 (95% credible interval = 0.20–0.26) to 0.51 (0.43–0.60) of available smolts. The cumulative effects of avian consumption were significantly lower for yearling and sub-yearling Chinook salmon, with consumption probabilities ranging annually from 0.04 (0.02–0.07) to 0.10 (0.07–0.15) and from 0.06 (0.3–0.09) to 0.15 (0.10–0.23), respectively. Avian consumption probabilities for sockeye salmon smolts was generally higher than for Chinook salmon smolts, but lower than for steelhead smolts, ranging annually from 0.08 (0.03–0.22) to 0.25 (0.14–0.44). Although annual consumption probabilities for birds from certain colonies were more than 0.20 of available smolts, probabilities from other colonies were less than 0.01 of available smolts, indicating that not all colonies of birds posed a substantial risk to smolt mortality. Consumption probabilities were lowest for small colonies and for colonies located a considerable distance from the Snake and Columbia rivers. Total mortality attributed to avian consumption was relatively small for Chinook salmon (less than 10%) but was the single greatest source of mortality for steelhead (greater than 50%) in all years evaluated. Results suggest that the potential benefits to salmonid populations of managing birds to reduce smolt mortality would vary widely depending on the salmonid population, the species of bird, and the size and location of the breeding colony.

Using predictions from multiple anthropogenic threats to estimate future population persistence of an imperiled species

Imperiled species face numerous and diverse anthropogenic threats to their persistence, and wildlife managers charged with making conservation decisions benefit from a sound understanding of how populations, species, and ecosystems will respond to future changes in threats to biodiversity. In southeastern North America, the gopher tortoise ( Gopherus polyphemus ) is a keystone species in upland ecosystems; however, tortoise populations have declined strongly over the last century, and the species is a candidate for increased protection by the United States federal government under the Endangered Species Act (ESA). Here, we sought to support conservation decision making for G. polyphemus by developing a spatially-explicit predictive population model that linked four anthropogenic threats (climate warming, sea-level rise, urbanization, habitat degradation) to demographic vital rates and used the model to estimate future changes in the number of individuals, populations, and metapopulations across the species’ range. Using recent survey data, we projected 457 populations for 80 years into the future under scenarios varying in threat magnitude, management magnitude, and demographic uncertainty. Population projections predicted that the number of individuals, populations, and metapopulations would decline among all simulated scenarios in the next 80 years. Model predictions were more sensitive to variation in adult survival and immigration rates than to variation in threat magnitude. A scenario with decreased habitat management and threat effects from climate warming, sea-level rise, and urbanization predicted geographic variation in persistence probabilities for populations that might result in decreased genetic representation across the species' range. Our results can be used to support conservation listing decisions for the gopher tortoise as part of its federal Species Status Assessment and provide an analytical framework for how to link diverse threats to geographically-varying demographic rates during population viability analyses for wide-ranging imperiled species around the world.

Using life-history trait variation to inform ecological risk assessments for threatened and endangered plant species.

Developing population models for assessing risks to terrestrial plant species listed as threatened or endangered under the Endangered Species Act (ESA) is challenging given a paucity of data on their life histories. The purpose of this study was to develop a novel approach for identifying relatively data-rich nonlisted species that could serve as representatives for species listed under the ESA in the development of population models to inform risk assessments. We used the USDA PLANTS Database, which provides data on plants present in the US territories, to create a list of herbaceous plants. A total of 8742 species was obtained, of which 344 were listed under the ESA. Using the most up-to-date phylogeny for vascular plants in combination with a database of matrix population models for plants (COMPADRE) and cluster analyses, we investigated how listed species were distributed across the plant phylogeny, grouped listed and nonlisted species according to their life history, and identified the traits distinguishing the clusters. We performed elasticity analyses to determine the relative sensitivity of population growth rate to perturbations of species' survival, growth, and reproduction and compared these across clusters and between listed and nonlisted species. We found that listed species were distributed widely across the plant phylogeny as well as clusters, suggesting that listed species do not share a common evolution or life-history characteristics that would make them uniquely vulnerable. Lifespan and age at maturity were more important for distinguishing clusters than were reproductive traits. For clusters that were intermediate in their lifespan, listed and nonlisted species responded similarly to perturbations of their life histories. However, for clusters at either extreme of lifespan, the response to survival perturbations varied depending on conservation status. These results can be used to guide the choice of representative species for population model development in the context of ecological risk assessment. Integr Environ Assess Manag 2023;19:213-223. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Potential Futures for Coastal Wolves and Their Ecosystem Services in Alaska, With Implications for Management of a Social-Ecological System

Carnivores across much of the world are declining, leading to loss of biodiversity as well as the ecosystem services carnivores provide. In 2020, the Alexander Archipelago (AA) wolf was petitioned for protection under the U.S. Endangered Species Act (ESA) for the third time in 30 years. Concerns included habitat alteration from industrial timber harvest and subsequent declines in prey (deer), human-caused mortality, climate change, and genetic inbreeding. However, the underlying biogeography and ecology of these wolves continues to suggest resiliency across the subspecies’ range, even though local populations may go extinct. If local wolf populations go extinct, it will result in loss of their ecosystem services (e.g., interactions of wolves with their prey, which prevents over-browsing and protects carbon sequestration in soils and trees), which will likely have major consequences for the local social-ecological system. Here, we updated a model we constructed for the last ESA listing process (2015) to examine the dynamics of wolf and deer populations on Prince of Wales Island (the primary geographic focus of all three petitions) in response to future environmental and management scenarios developed with stakeholders. Further, we considered how changes in deer abundance impact predation services (prevention of over-browsing by deer). We found that wolf populations generally persisted over 30 years, but dropped below an effective population size of 50 wolves in 10–98% of years simulated. Low wolf abundance resulted in higher deer abundance, which increased hunting opportunity, but also browsing damages (e.g., 19% of areas would be over-browsed if wolf harvest caps are removed, and >30% of areas would be over-browsed if wolves go extinct). Human harvest of wildlife was a key regulator of abundance and ecosystem services within the coastal rainforest social-ecological system; wolf abundance was most affected by wolf harvest regulations; and deer harvest restrictions increased wolf and deer abundances, but also greatly increased browsing impacts (>70% of areas heavily browsed if hunting ceased). Our findings support an integrated approach to management of this social-ecological system, such that social and ecological sciences are both used to monitor important components of the system (e.g., measuring public sentiment and likelihood of poaching, alongside wolf and deer numbers). Integration and adaptive approaches are needed to ensure that the many ecosystem services humans depend on are valued, conserved, and restored, including the cryptic predation services wolves have historically provided to the timber industry via reduced browsing pressure by deer.

Investigation of crayfish abundance in proximity to bridges, with emphasis on the Threatened Big Sandy crayfish (C. callainus)

The Big Sandy Crayfish, Cambarus callainus, is a large-bodied crustacean which inhabits third order streams within the Levisa, Tug, and Russel Fork basins throughout the conjunction of West Virginia, Virginia, and Kentucky. In 2016, C. callainus was federally designated as Threatened under the Endangered Species Act (ESA), which ushered in long‑needed attention and protection for the species. ESA benefits are broad in scope and highly beneficial to the species persistence and recovery. However, such broad levels of protection necessitate intense levels of scrutiny and regulation for development projects transpiring near confirmed or expected occurrences of protected species. West Virginia as a whole needs updated infrastructure, and this is especially true for the southern coalfields where C. callainus persists. Due to recent surges of funding through the Infrastructure Investment and Jobs Act, West Virginia is set to receive $3.7 billion dollars designated specifically for the repair or replacement of bridges and highways. Many bridges on the docket for maintenance/reconstruction cross streams within C. callainus distribution. Herein, I propose a C. callainus crayfish survey and habitat modeling project to determine whether this species exhibits preference, avoidance, or indifference to those bridge crossings in most dire need of repair or replacement. This project will enable private and public infrastructure entities to more efficiently generate mitigation and harm‑reduction protocols, and will reduce unexpected expenditures related to ESA protections.

Habitat Conservation Plans provide limited insight into the cost of complying with the Endangered Species Act

AbstractThe Endangered Species Act (ESA) mandates protection for listed species, prohibiting intentionally adverse “take” by both public and private activities. The requirements can be perceived as a costly regulatory burden, although minimal understanding of the costs of compliance actions may exacerbate the perceived burden. This has potential consequences for ESA effectiveness and species recovery. We developed a framework to identify when compliance costs could be incurred in a project and then analyzed projected cost data from published Habitat Conservation Plans (HCPs) using this framework. We found that across HCPs, the projected costs reported were incomplete and difficult to interpret with inconsistent reporting across documents. Within the 43 HCPs that had utilizable cost data, the majority of projected costs (77%–97%) were incurred by implementation of ESA compliance activities. Of these, 46% of expected implementation costs were for monitoring efforts for project‐scale HCPs, while 81% of implementation costs for large‐scale projects were for compensatory mitigation actions. Our results provide a first attempt at analyzing the cost of ESA compliance actions using HCPs. However, we found that costs reported in HCPs tended to be opaque and incomplete, underscoring the need for standardization of cost reporting to better support understanding of ESA compliance costs.

A data accuracy evaluation strategy to improve the representation of potential pesticide use areas for endangered species assessments.

The use of "best available data" is a fundamental requirement for all scientific forms of analysis. This paper discusses ways to improve the accuracy of data used to evaluate the potential impacts of pesticides on species that are listed as threatened or endangered under the Endangered Species Act (ESA) by ensuring the best available spatial data representing pesticide use sites are applied correctly. A decision matrix is presented that uses accuracy information from metadata contained in the US Department of Agriculture's (USDA's) Cropland Data Layer (CDL) and the Census of Agriculture (CoA) to improve how labeled pesticide use sites are spatially delineated. We suggest recommendations for the current pesticide evaluation process used by the US Environmental Protection Agency (USEPA) and subsequently by the US Fish and Wildlife Services and National Marine Fisheries Service (collectively known as the Services) in Section 7 consultation activities. The decision matrix is applied to each cultivated land layer in the USDA's CDL with recommendations for how best to use each layer in the evaluation process. Application of this decision matrix will lead to improved representation of labeled uses and more accurate overlap calculations used in the assessment of potential impacts of pesticides on endangered species. Integr Environ Assess Manag 2022;18:1655-1666. © 2022 SETAC.

Value of an Endangered Species

In the United States, the Endangered Species Act (ESA) represents the federal government’s paramount effort to protect endangered species. In no uncertain terms, the ESA prohibits harming endangered species by both private and governmental actors. Moreover, the Supreme Court determined that the ESA prevents courts from exercising their usual discretion when such actors take actions that will foreseeably result in harm to endangered species. Put simply, the ESA prevents courts from allowing harm to come to endangered species even if that harm is necessary for an immense benefit to human beings. This broad protection has been effective in preventing ecological loss in the U.S. But because of the breadth of the statute, courts must sometimes resolve disputes where harm to an endangered species is necessary to protect human health and safety. In these cases, courts have severely narrowed the ESA’s protections. Furthermore, changes in human and animal migration caused by climate change will pit human health against the welfare of endangered species far more often. Without better guidance from Congress, courts will likely continue to erode the strength of the ESA. This Note proposes expanding the ESA’s exemption process in order to forestall foundational attacks on the statute. By addressing this issue now, Congress can preserve the ESA’s core protections against increasingly problematic precedent.

Passive sampling and ecohydrologic modeling to investigate pesticide surface water loading in the Zollner Creek watershed, Oregon, USA

In the U.S. Pacific Northwest and California contaminants entering surface water may harm Endangered Species Act (ESA) listed salmonid species and consequently there is ongoing concern regarding agricultural practices and resulting pesticide surface water loading may adversely impact salmonid species, their food web, and habitat. Characterizing pesticide exposure in surface water at the watershed scale and beyond is challenging due to uncertainty regarding pesticide use practices and sparse monitoring data. We report here a 2-year continuous deployment of passive sampling devices (PSDs) for monitoring of pesticides in surface water at the outflow of the Zollner Creek watershed located within the Willamette Basin, Oregon, USA. This watershed is predominately agricultural and within the geographic range of two ESA listed Pacific salmonid species. Grab and passive sampling monitoring data were used to evaluate the performance of a probabilistic application of the Soil and Water Assessment Tool (SWAT), a physically based process model which integrates institutional and local knowledge and expertise to investigate the relationship between land use practices and pesticide surface water loading at the watershed scale. SWAT estimated pesticide surface water concentrations for the pesticides chlorpyrifos and trifluralin followed temporal trend in PSD monitoring results and the 5th to 95th percentile range of estimated pesticide concentrations based on the probabilistic assessment encompassed 65–76% of the observed PSD concentrations. Evaluation of model estimates for metolachlor in surface water was challenged by insufficient publicly available grab sample monitoring data. A process to estimate pesticide surface water concentrations on biologically relevant time scales and comparison to screening level aquatic life benchmarks is presented. Additionally, model estimates were used to characterize the variance in surface water concentrations in this small hydrologically responsive watershed to determine grab sampling frequency adequate for model evaluation.

Historical DNA from Museum Shell Collections: Evaluating the Suitability of Dried Micromollusks for Molecular Systematics

Natural history collections are an invaluable resource that can inform systematic studies and biodiversity discovery, and also contribute to understanding changes in species abundance and distributions over time. The decline in abundance and diversity of Pacific Island land snails has been a major conservation concern for more than six decades, but only the largest and most colorful snails are protected under the US Endangered Species act, and few are listed as critically endangered on the IUCN Red List. Like most invertebrates, the conservation status of many Hawaiian land snails still need assessment. Molecular data are highly informative for revising species limits and understanding evolutionary patterns and processes, but with as much as 70% of Hawaiian land snails already extinct, few fresh samples are available from which to extract DNA. To overcome the lack of material suitable for DNA barcoding, we test whether short DNA fragments of 225 to 355 bp can be sequenced from museum snail shells containing dried tissues collected more than 50 years ago. Short DNA sequences (225 bp) were obtained from 66.7% of lots, while longer DNA sequences (355 bp) were successfully sequenced from 24.2% of lots. Snail specimens stored in natural history cabinets for more than 100 years were successfully sequenced, supporting the inclusion of these materials for modern biodiversity studies. Molecular data from this study represents a small proportion of Hawaiian microsnail species housed among the millions of specimens in the Bishop Museum in Hawaii and other natural history collections. Additional resources and focused efforts are needed to scale this approach to incorporate many more of the hundreds of snail species in need of assessment in Hawaii. More broadly, there are large representative collections of endangered Pacific Island non-marine snails in many natural history museums that may be suitable for molecular work, either with DNA barcoding or other genomic approaches.

Status of the Recovery Mandate Under Section 7(a)(1) of the U.S. Endangered Species Act

The U.S. Endangered Species Act (ESA) is widely considered to be one of the strongest laws for protecting imperiled wildlife, with nearly all species protected under the law still existing today. Among the ESA's strongest provisions, at least as written, is the requirement under section 7(a)(1) that federal agencies use their authorities to help recover imperiled species. New initiatives like 30 x 30, the campaign to conserve at least 30% of U.S. lands and waters by 2030, offer opportunities to reinvigorate and expand 7(a)(1) programs to play a significant role in biodiversity conservation. To gauge the current status of 7(a)(1) plans and assess their effectiveness, we collected all section 7(a)(1) materials available to the public through internet searches and direct requests to agencies. We evaluated the scope of existing 7(a)(1) programs and found that despite the clear potential benefits of strong programs, the section has been significantly underused by federal agencies. Further, we show that existing plans are highly inconsistent in content and style, and we trace that inconsistency to the lack of policy guidance for their creation and implementation. Based on these findings, we recommend five strategies for improving 7(a)(1) implementation: establishment of formal guidance from the federal wildlife agencies, tailored guidance from other federal agencies to help them meet their 7(a)(1) obligation, dedicated funding, integration of 7(a)(1) into existing initiatives and opportunities, and top-level executive branch coordination and cooperation.

How Protective to the Environment is the Pesticide Risk Assessment and Registration Process in the United States?

The media, public, and other stakeholders are generally unaware of the degree of protection provided to the environment by the current pesticide registration process in the United States. Each pesticide product must meet extensive fate and toxicological data requirements (typically 100+ studies) to be considered by the U.S. Environmental Protection Agency (EPA). The EPA uses that information to conduct ecological, human health, and benefits assessments and make decisions on whether to register pesticides and, if so, under what conditions. The assessments rely on conservative assumptions, models, and inputs to consistently err on the side of caution throughout the pesticide registration process. The rigorous compliance requirements specified in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and Endangered Species Act (ESA) are designed to preclude unacceptable adverse effects. However, this reality seldom, if ever, makes headlines. Pesticides are not causing the dire widespread apocalyptic effects often portrayed by some media outlets. Rather, pesticides have been doing what they were intentionally designed to do, controlling pests and increasing yields, within the stringent limitations of registered labels. The continually evolving pesticide registration process was originally predicated on the unintended adverse effects neither anticipated nor considered over 50 years ago, due to insufficient regulation and oversight at the time. However, the contemporary regulatory paradigm in the U.S. is data rich and analysis intensive by design, and perhaps understandably, biased towards ensuring environmental protection when registering pesticides. https://doi.org/10.21423/jrs-v09i2moore

The call of the emperor penguin: Legal responses to species threatened by climate change.

Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Aptenodytes forsteri), currently being considered for protection under the US Endangered Species Act (ESA). This species forms colonies on Antarctic sea ice, which is projected to significantly decline due to ongoing greenhouse gas (GHG) emissions. We project the dynamics of all known emperor penguin colonies under different GHG emission scenarios using a climate‐dependent meta‐population model including the effects of extreme climate events based on the observational satellite record of colonies. Assessments for listing species under the ESA require information about how species resiliency, redundancy and representation (3Rs) will be affected by threats within the foreseeable future. Our results show that if sea ice declines at the rate projected by climate models under current energy system trends and policies, the 3Rs would be dramatically reduced and almost all colonies would become quasi‐extinct by 2100. We conclude that the species should be listed as threatened under the ESA.

A tale of two valleys: endangered species policy and the fate of the giant gartersnake

By the mid-20th Century, giant gartersnakes (Thamnophis gigas) had lost more than 90% of their Central Valley marsh habitat and were extirpated from more than two-thirds of their range. This massive habitat loss led to their inclusion in the inaugural list of rare species under the California Endangered Species Act (CESA). Listing under the CESA provided giant gartersnakes legal protection and mechanisms for recovery, and subsequent listing under the U.S. Endangered Species Act (federal ESA) further fortified these protections. But how effective has listing under these endangered species acts (ESAs) been at achieving their goal of giant gartersnake recovery? Herein, we review relevant aspects of giant gartersnake ecology, illustrate how listing has benefited giant gartersnakes and what challenges have been faced in slowing declines and recovering populations, and chart a course toward improved conservation, management, and recovery of giant gartersnakes. Although listing as threatened under both state and federal ESAs has not yet achieved recovery of giant gartersnakes, the increased knowledge gained and mechanisms for protecting giant gartersnake habitat on private and public lands developed over the past 50 years has improved conservation of this endemic California snake.

Development of ecologically meaningful, multiple-species conservation strategies under the California and U.S. Endangered Species Acts

The California and U.S. Endangered Species Acts prohibit take of protected species, but allow for authorization of take incidental to otherwise lawful activities provided the take is minimized and mitigated. Incomplete and inconsistent ecological information can limit the contribution of mitigation plans for incidental take, especially those for multiple species, to species persistence. Many such plans focus on acquisition and management of coarse-resolution land-cover or land-use types. These classifications may not coincide with a species’ resource requirements (its habitat) or the greatest constraints to its viability. Complementing acquisition with rigorous research on population biology, stressors, and habitat use and quality may be much more effective than preservation of putative but unproven habitat. Such adaptive conservation can be applied to species with restricted or extensive distributions. When the distribution and ecology of geographically restricted species are well-known, then connectivity analyses, sometimes complemented by spatially explicit, mechanistic population models, may inform habitat acquisition and management. When little information exists on the ecology or vital rates of a restricted species, we suggest assessment of occupancy, habitat use, or demography; tracking individuals’ movements; and evaluation of habitat quality. Acquisition and management of local lands that may not serve as habitat is unlikely to contribute to conservation of extensively distributed species with range-wide declines. Instead, we suggest that conservation efforts for these species emphasize strategic acquisition of open space (large, undeveloped areas that are more likely to serve as high-quality habitat), potentially in locations distant from the permit area. The above areas of research can inform optimization of conservation locations. Many mitigation decisions are based on assumptions drawn from limited data. Inclusion of scientific research in development and implementation of mitigation plans for incidental take can strengthen the plans’ information content, improve the ecological success acquisition and management, and advance conservation of protected species.

Improving species status assessments under the U.S. Endangered Species Act and implications for multispecies conservation challenges worldwide

Despite its successes, the U.S. Endangered Species Act (ESA) has proven challenging to implement due to funding limitations, workload backlog, and other problems. As threats to species survival intensify and as more species come under threat, the need for the ESA and similar conservation laws and policies in other countries to function efficiently has grown. Attempts by the U.S. Fish and Wildlife Service (USFWS) to streamline ESA decisions include multispecies recovery plans and habitat conservation plans. We address species status assessment (SSA), a USFWS process to inform ESA decisions from listing to recovery, within the context of multispecies and ecosystem planning. Although existing SSAs have a single‐species focus, ecosystem‐based research can efficiently inform multiple SSAs within a region and provide a foundation for transition to multispecies SSAs in the future. We considered at‐risk grassland species and ecosystems within the southeastern United States, where a disproportionate number of rare and endemic species are associated with grasslands. To initiate our ecosystem‐based approach, we used a combined literature‐based and structured World Café workshop format to identify science needs for SSAs. Discussions concentrated on 5 categories of threats to grassland species and ecosystems, consistent with recommendations to make shared threats a focus of planning under the ESA: (1) habitat loss, fragmentation, and disruption of functional connectivity; (2) climate change; (3) altered disturbance regimes; (4) invasive species; and (5) localized impacts. For each threat, workshop participants identified science and information needs, including database availability, research priorities, and modeling and mapping needs. Grouping species by habitat and shared threats can make the SSA process and other planning processes for conservation of at‐risk species worldwide more efficient and useful. We found a combination of literature review and structured discussion effective for identifying the scientific information and analysis needed to support the development of multiple SSAs. Article impact statement: Species status assessments can be improved by an ecosystem‐based approach that groups imperiled species by shared habitats and threats.