Prioritizing resource allocation to reduce adverse effects of pesticide risk for endangered species.

The use of pesticides promotes food security because of the multiple benefits it brings to agriculture, such as reduction in crop losses. However, the use of pesticides can be potentially harmful to non-target species. In the U.S., the Environmental Protection Agency regulates the use of pesticides to manage the risks associated with these agents and to protect species under the Endangered Species Act. As part of these regulations, pesticides must be registered and then reviewed every 15 years to ensure the use conditions are updated with the best available data. The registration and review process can invoke corrective measures to ensure protection of endangered species. However, the registration review process is highly resource and time consuming. There is currently a backlog of unreviewed pesticides, leaving a large quantity of pesticides without updated use conditions to protect species. Identifying ways to streamline this process is urgently needed. We develop a sequencing approach to address the risk assessment bottleneck in the pesticide registration and review process and identify species that would benefit most from detailed assessments. We then demonstrate the magnitude of potential efficiencies using this sequencing process for 61 terrestrial listed species in the state of California. Our results show a consistent ranking of listed species according to their relative benefits from assessment, with 90 % of the species being robustly classified across scenarios in the sensitivity analysis. We found that prioritizing the assessment of a small group of species could potentially result in high conservation benefits, and identify species in need of more detailed data for a robust sequencing. We examine how a sequencing approach can guide decisions about what species might benefit most from different levels of assessment. Our results demonstrate the conservation benefits of employing a sequencing approach to prioritize the allocation of limited resources for endangered species.

Attributes of preemptive conservation efforts for species precluded from listing under the U.S. Endangered Species Act.

Preemptive conservation efforts to reduce threats have been credited with precluding the need to list some imperiled species under the U.S. Endangered Species Act (ESA). Such efforts can result in outcomes where species are conserved and regulatory costs associated with ESA listing are avoided. Yet, the extent and type of conservation effort involved in achieving preclusion from listing are not well understood. We quantified the attributes of conservation efforts identified as important for 43 species whose preclusion from listing was attributed to conservation efforts, as described in U.S. Federal Register documents that report the decisions not to list. We considered 2 features of preemptive conservation: effort applied (measured as the number of conservation initiatives) and number of conservation partners involved. We also quantified the type and location of conservation actions. We found a mean of 4.3 initiatives (range 1-22) and 8.2 partners (range 1-31) documented per precluded species; both measures of conservation effort were significantly and positively associated with the species' range area and the proportion of private land across its range. The number of initiatives was also positively related to the number of threats affecting a species. Locations of conservation actions varied; more species had actions on public land than on private land (p = 0.003). Numbers of species with restorative actions (e.g., invasive species control) were similar to numbers with prohibitive actions. Our findings highlight relationships between species' context and preemptive conservation activities, providing a first cross-species analysis of conservation efforts for species that were precluded from listing under the ESA due to conservation.

Atributos de los esfuerzos preventivos de conservación para las especies excluidas del listado de la Ley de Especies en Peligro de Extinción de Estados Unidos Resumen A los esfuerzos preventivos de conservación para reducir las amenazas se les atribuye la exclusión de algunas especies en peligro de la lista de la Ley de Especies en Peligro de Extinción de los Estados Unidos (ESA, en inglés). Dichos esfuerzos pueden tener resultados en los que se protegen las especies y se evitan los costos regulatorios asociados con el listado de la ESA, pero no se sabe mucho sobre el alcance y el tipo de esfuerzo de conservación involucrados en la exclusión del listado. Cuantificamos los atributos de los esfuerzos de conservación identificados como importantes para 43 especies cuya exclusión del listado fue atribuida a los esfuerzos de conservación, descrito así en los documentos del Registro Federal de los EUA que reportan las razones para no incluirlas en la lista. Consideramos dos características de la conservación preventiva: el esfuerzo aplicado (medido como el número de iniciativas de conservación) y el número de socios de conservación involucrados. También cuantificamos el tipo y ubicación de las acciones de conservación. Obtuvimos una media de 4.3 iniciativas (rango 1­22) y 8.2 socios (rango 1­31) documentados por especie excluida; ambas medidas del esfuerzo de conservación tuvieron una asociación significativa y positiva con el área de distribución de la especie y la proporción de suelo privado en esta distribución. El número de iniciativas también tuvo una relación positiva con el número de amenazas para las especies. Las ubicaciones de las acciones de conservación variaron y más especies contaban con acciones en suelo público que en suelo privado (p = 0.003). El número de especies que contaban con acciones de restauración (p. ej.: control de especies invasoras) fue similar a aquellas con acciones prohibitivas. Nuestros hallazgos resaltan la relación entre el contexto de la especie y las actividades preventivas de conservación, lo que proporciona un primer análisis entre especies de los esfuerzos de conservación para especies excluidas de la ESA por cuestiones de conservación.

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.

Factores asociados a la conservación preventiva bajo el Acta de Especies en Peligro de los EE. UU. Resumen Durante las últimas décadas ha existido un incremento en los esfuerzos proactivos para conservar a las especies consideradas para ser incluidas en el Acta de Especies en Peligro de los EE. UU. (AEP) antes de ser añadidas a la lista (es decir, conservación preventiva). Estos esfuerzos, que dependen de las acciones voluntarias realizadas por los administradores de las tierras públicas y privadas en la distribución de la especie, buscan conservar a la especie y evitar los costos reglamentarios asociados con su inclusión en el AEP. Recolectamos datos para un conjunto de factores sociales, económicos, ambientales e institucionales que planteamos influirían sobre las decisiones voluntarias para promover o inhibir la conservación preventiva de las especies consideradas para ser enlistadas en el AEP. Usamos la regresión logística para estimar la asociación de estos factores con los resultados de la conservación preventiva con base en los datos de un conjunto de especies que entraron al proceso de listado en el AEP y que terminaron en la lista oficial (n = 314) o con conservación preventiva (n = 73) entre 1996 y 2018. Los factores asociados significativamente con el listado excluyente debido a la conservación preventiva incluyeron: un estado de conservación con una línea base elevada, una baja proporción de suelo privado en la distribución de la especie, un tamaño pequeño de la distribución total, la exposición a tipos específicos de amenazas, y la distribución de la especie extendida por varios estados. Estos resultados resaltan las estrategias que pueden ayudar a mejorar los resultados de conservación, como la asignación anticipada de recursos para especies en peligro durante el proceso de listado, abordar las amenazas específicas y la expansión de incentivos y mecanismos de coordinación para la conservación en suelo privado.

Private land conservation decision-making: An integrative social science model.

Owners and managers of private lands make decisions that have implications well beyond the boundaries of their land, influencing species conservation, water quality, wildfire risk, and other environmental outcomes with important societal and ecological consequences. Understanding how these decisions are made is key for informing interventions to support better outcomes. However, explanations of the drivers of decision making are often siloed in social science disciplines that differ in focus, theory, methodology, and terminology, hindering holistic understanding. To address these challenges, we propose a conceptual model of private land conservation decision-making that integrates theoretical perspectives from three dominant disciplines: economics, sociology, and psychology. The model highlights how heterogeneity in behavior across decision-makers is driven by interactions between the decision context, attributes of potential conservation behaviors, and attributes of the decision-maker. These differences in both individual attributes and context shape decision-makers' constraints and the potential and perceived consequences of a behavior. The model also captures how perceived consequences are evaluated and weighted through a decision-making process that may range from systematic to heuristic, ultimately resulting in selection of a behavior. Outcomes of private land behaviors across the landscape feed back to alter the socio-environmental conditions that shape future decisions. The conceptual model is designed to facilitate better communication, collaboration, and integration across disciplines and points to methodological innovations that can expand understanding of private land decision-making. The model also can be used to illuminate how behavior change interventions (e.g., policies, regulations, technical assistance) could be designed to target different drivers to encourage environmentally and socially beneficial behaviors on private lands.

Space use and habitat selection of an invasive mesopredator and sympatric, native apex predator.

BACKGROUND: Where mesopredators co-exist with dominant apex predators, an understanding of the factors that influence their habitat and space use can provide insights that help guide wildlife conservation and pest management actions. A predator's habitat use is defined by its home range, which is influenced by its selection or avoidance of habitat features and intra- and inter-specific interactions within the landscape. These are driven by both innate and learned behaviour, operating at different spatial scales. We examined the seasonal home ranges and habitat selection of actively-managed populations of a native apex predator (dingo Canis dingo) and invasive mesopredator (feral cat Felis catus) in semi-arid Western Australia to better understanding their sympatric landscape use, potential interactions, and to help guide their management. METHODS: We used kernel density estimates to characterise the seasonal space use of dingoes and feral cats, investigate inter- and intra-species variation in their home range extent and composition, and examine second-order habitat selection for each predator. Further, we used discrete choice modelling and step selection functions to examine the difference in third-order habitat selection across several habitat features. RESULTS: The seasonal home ranges of dingoes were on average 19.5 times larger than feral cats. Feral cat seasonal home ranges typically included a larger proportion of grasslands than expected relative to availability in the study site, indicating second-order habitat selection for grasslands. In their fine-scale movements (third-order habitat selection), both predators selected for roads, hydrological features (seasonal intermittent streams, seasonal lakes and wetlands), and high vegetation cover. Dingoes also selected strongly for open woodlands, whereas feral cats used open woodlands and grasslands in proportion to availability. MANAGEMENT RECOMMENDATIONS: Based on these results, and in order to avoid unintended negative ecological consequences (e.g. mesopredator release) that may stem from non-selective predator management, we recommend that feral cat control focuses on techniques such as trapping and shooting that are specific to feral cats in areas where they overlap with apex predators (dingoes), and more general techniques such as poison baiting where they are segregated.

Standardized reporting of the costs of management interventions for biodiversity conservation.

Effective conservation management interventions must combat threats and deliver benefits at costs that can be achieved within limited budgets. Considerable effort has focused on measuring the potential benefits of conservation interventions, but explicit quantification of the financial costs of implementation is rare. Even when costs have been quantified, haphazard and inconsistent reporting means published values are difficult to interpret. This reporting deficiency hinders progress toward a collective understanding of the financial costs of management interventions across projects and thus limits the ability to identify efficient solutions to conservation problems or attract adequate funding. We devised a standardized approach to describing financial costs reported for conservation interventions. The standards call for researchers and practitioners to describe the objective and outcome, context and methods, and scale of costed interventions, and to state which categories of costs are included and the currency and date for reported costs. These standards aim to provide enough contextual information that readers and future users can interpret the cost data appropriately. We suggest these standards be adopted by major conservation organizations, conservation science institutions, and journals so that cost reporting is comparable among studies. This would support shared learning and enhance the ability to identify and perform cost-effective conservation.

Factoring economic costs into conservation planning may not improve agreement over priorities for protection.

Conservation organizations must redouble efforts to protect habitat given continuing biodiversity declines. Prioritization of future areas for protection is hampered by disagreements over what the ecological targets of conservation should be. Here we test the claim that such disagreements will become less important as conservation moves away from prioritizing areas for protection based only on ecological considerations and accounts for varying costs of protection using return-on-investment (ROI) methods. We combine a simulation approach with a case study of forests in the eastern United States, paying particular attention to how covariation between ecological benefits and economic costs influences agreement levels. For many conservation goals, agreement over spatial priorities improves with ROI methods. However, we also show that a reliance on ROI-based prioritization can sometimes exacerbate disagreements over priorities. As such, accounting for costs in conservation planning does not enable society to sidestep careful consideration of the ecological goals of conservation.

Waiting can be an optimal conservation strategy, even in a crisis discipline.

Biodiversity conservation projects confront immediate and escalating threats with limited funding. Conservation theory suggests that the best response to the species extinction crisis is to spend money as soon as it becomes available, and this is often an explicit constraint placed on funding. We use a general dynamic model of a conservation landscape to show that this decision to "front-load" project spending can be suboptimal if a delay allows managers to use resources more strategically. Our model demonstrates the existence of temporal efficiencies in conservation management, which parallel the spatial efficiencies identified by systematic conservation planning. The optimal timing of decisions balances the rate of biodiversity decline (e.g., the relaxation of extinction debts, or the progress of climate change) against the rate at which spending appreciates in value (e.g., through interest, learning, or capacity building). We contrast the benefits of acting and waiting in two ecosystems where restoration can mitigate forest bird extinction debts: South Australia's Mount Lofty Ranges and Paraguay's Atlantic Forest. In both cases, conservation outcomes cannot be maximized by front-loading spending, and the optimal solution recommends substantial delays before managers undertake conservation actions. Surprisingly, these delays allow superior conservation benefits to be achieved, in less time than front-loading. Our analyses provide an intuitive and mechanistic rationale for strategic delay, which contrasts with the orthodoxy of front-loaded spending for conservation actions. Our results illustrate the conservation efficiencies that could be achieved if decision makers choose when to spend their limited resources, as opposed to just where to spend them.

Limitations of outsourcing on-the-ground biodiversity conservation.

To counteract global species decline, modern biodiversity conservation engages in large projects, spends billions of dollars, and includes many organizations working simultaneously within regions. To add to this complexity, the conservation sector has hierarchical structure, where conservation actions are often outsourced by funders (foundations, government, etc.) to local organizations that work on-the-ground. In contrast, conservation science usually assumes that a single organization makes resource allocation decisions. This discrepancy calls for theory to understand how the expected biodiversity outcomes change when interactions between organizations are accounted for. Here, we used a game theoretic model to explore how biodiversity outcomes are affected by vertical and horizontal interactions between 3 conservation organizations: a funder that outsourced its actions and 2 local conservation organizations that work on-the-ground. Interactions between the organizations changed the spending decisions made by individual organizations, and thereby the magnitude and direction of the conservation benefits. We showed that funders would struggle to incentivize recipient organizations with set priorities to perform desired actions, even when they control substantial amounts of the funding and employ common contracting approaches to enhance outcomes. Instead, biodiversity outcomes depended on priority alignment across the organizations. Conservation outcomes for the funder were improved by strategic interactions when organizational priorities were well aligned, but decreased when priorities were misaligned. Meanwhile, local organizations had improved outcomes regardless of alignment due to additional funding in the system. Given that conservation often involves the aggregate actions of multiple organizations with different objectives, strategic interactions between organizations need to be considered if we are to predict possible outcomes of conservation programs or costs of achieving conservation targets.

Experimental test for facilitation of seedling recruitment by the dominant bunchgrass in a fire-maintained savanna.

Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites. We hypothesized that the dominant bunch grass species (Aristida stricta Michx.) would facilitate moist seedling microsites through shading, but that the effect would depend on stress gradients. Here, we examined the environmental properties modified by the presence of wiregrass and tested the importance of increased shade as a potential facilitative mechanism promoting seedling recruitment across spatial and temporal stress gradients. We showed that environmental gradients, season, and experimental water manipulation influence seedling success. Environmental properties were modified by wiregrass proximity in a manner that could facilitate seedling success, but we showed that shade alone does not provide a facilitative benefit to seedlings in this system.

Effects of resource availability on seedling recruitment in a fire-maintained savanna.

The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity. To understand the potential mechanistic controls on species richness, we used a long-term resource manipulation study across a natural soil moisture gradient to assess environmental controls on seedling recruitment. We considered the availability of resources to be an indicator of seedling safe-site supply, and also manipulated seed availability to examine the relative importance of recruitment limitations on seedling diversity. We found that water availability regulated the number of species in the seedling community regardless of the underlying natural moisture gradient, and that this effect may result from differential responses of seedling guilds to resource availability. Water supply was more important than seed supply in determining seedling establishment, suggesting that appropriate sites for regeneration are a factor limiting seedling success. This is the first study that shows that the episodic supply of microsites for recruitment could influence species richness in the highly threatened and biodiverse longleaf pine savanna.