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Extinction risk is elevated in small, isolated populations due to demographic and genetic interactions. Therefore, it is critical to model these processes realistically in population viability analyses (PVA) to inform local management and contribute to a greater understanding of mechanisms within the extinction vortex. We conducted PVA’s for two small mountain lion populations isolated by urbanization in southern California to predict population growth, extinction probability, and loss of genetic diversity with empirical data. Specifically, we (1) provide the first PVA for isolated mountain lions in the Santa Ana Mountains (SAM) that considers both demographic and genetic risk factors and (2) test the hypothesis that variation in abundance and mortality between the SAM and Santa Monica Mountains (SMM) result in differences in population growth, loss of heterozygosity, and extinction probability. Our models predicted 16–21% probability of local extinction in the SAM due purely to demographic processes over 50 yr with current low levels or no immigration. Our models also predicted that genetic diversity will further erode in the SAM such that concern regarding inbreeding depression is warranted unless gene flow is increased, and that if inbreeding depression occurs, rapid local extinction will be highly likely. Dynamics of the two populations were broadly similar, but they also exhibited differences driven by larger population size and higher mortality in the SAM. Density-independent scenarios predicted a rapidly increasing population in the SMM, whereas growth potential did not differ from a stable trend in the SAM. Demographic extinction probability and loss of heterozygosity were greater in the SMM for density-dependent scenarios without immigration. However, higher levels of immigration had stronger, positive influences on both demographic viability and retention of genetic diversity in the SMM driven by lower abundance and higher adult survival. Our results elucidate demographic and genetic threats to small populations within the extinction vortex, and how these vary relative to demographic structure. Importantly, simulating seemingly attainable increases in connectivity was sufficient to greatly reduce extinction probability. Our work highlights that conservation of large carnivores is achievable within urbanized landscapes, but requires land protection, connectivity, and strategies to promote coexistence with humans.

1. Predicting population responses to environmental conditions or management scenarios is a fundamental challenge for conservation. Proper consideration of demographic, environmental and parameter uncertainties is essential for projecting population trends and optimal conservation strategies. 2. We developed a coupled integrated population model-Bayesian population viability analysis to assess the (1) impact of demographic rates (survival, fecundity, immigration) on past population dynamics; (2) population viability 10 years into the future; and (3) efficacy of possible management strategies for the federally endangered Great Lakes piping plover Charadrius meiodus population. 3. Our model synthesizes long-term population survey, nest monitoring and mark-resight data, while accounting for multiple sources of uncertainty. We incorporated latent abundance of eastern North American merlins Falco columbarius, a primary predator of adult plovers, as a covariate on adult survival via a parallel state-space model, accounting for the influence of an imperfectly observed process (i.e. predation pressure) on population viability. 4. Mean plover abundance increased from 18 pairs in 1993 to 75 pairs in 2016, but annual population growth (λ̄t) was projected to be 0.95 (95% Cl 0.72-1.12), suggesting a potential decline to 67 pairs within 10 years. Without accounting for an expanding merlin population, we would have concluded that the plover population was projected to increase (λ̄t = 1.02; 95% Cl 0.94-1.09) to 91 pairs by 2026. We compared four conservation scenarios: (1) no proposed management; (2) increased control of chick predators (e.g. Corvidae, Laridae, mammals); (3) increased merlin control; and (4) simultaneous chick predator and merlin control. Compared to the null scenario, chick predator control reduced quasi-extinction probability from 11.9% to 8.7%, merlin control more than halved (3.5%) the probability and simultaneous control reduced quasi-extinction probability to 2.6%. 5. Synthesis and applications. Piping plover recovery actions should consider systematic predator control, rather than current ad hoc protocols, especially given the predicted increase in regional merlin abundance. This approach of combining integrated population models with Bayesian population viability analysis to identify limiting components of the population cycle and evaluate alternative management strategies for conservation decision-making shows great utility for aiding recovery of threatened populations.

One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and long-term viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus). We used an individual-based model for population viability analysis (PVA) that incorporated adaptive patterns of caribou movement in relation to predation risk and food availability to predict stochastic variation in rates of caribou survival. Field estimates of annual survival rates for adult female caribou in the unlogged (x̄ = 0.90) and logged (x̄ = 0.76) study sites recorded during 2010–2014 did not differ significantly (P > 0.05) from values predicted by the individual-based PVA model (unlogged: x̄ = 0.87; logged: x̄ = 0.79). Outcomes from the individual-based PVA model and a simpler stage-structured matrix model suggest that substantial differences in adult survival largely due to wolf predation are likely to lead to long-term decline of woodland caribou in the commercially logged landscape, whereas the unlogged landscape should be considerably more capable of sustaining caribou. Estimates of population growth rates (λ) for the 2010–2014 period differed little between the matrix model and the individual-based PVA model for the unlogged (matrix model x̄ = 1.01; individual-based model x̄ = 0.98) and logged landscape (matrix model x̄ = 0.88; individual-based model x̄ = 0.89). We applied the spatially explicit PVA model to assess the viability of woodland caribou across 14 woodland caribou ranges in Ontario. Outcomes of these simulations suggest that woodland caribou ranges that have experienced significant levels of commercial forestry activities in the past had annual growth rates <0.89, whereas caribou ranges that had not experienced commercial forestry operations had population growth rates >0.96. These differences were strongly related to regional variation in wolf densities. Our results suggest that increased wolf predation risk due to anthropogenic disturbance is of sufficient magnitude to cause appreciable risk of population decline in woodland caribou in Ontario.

Population viability analysis (PVA) is useful in management of imperiled species. Applications range from research design, threat assessment, and development of management frameworks. Given the importance of PVAs, it is essential that they be rigorous and adhere to widely accepted guidelines; however, the quality of published PVAs is rarely assessed. We evaluated the quality of 160 PVAs of 144 species of birds and mammals published in peer-reviewed journals from 1990 to 2017. We hypothesized that PVA quality would be lower with generic programs than with custom-built programs; be higher for those developed for imperiled species; change over time; and be higher for those published in journals with high impact factors (IFs). Each included study was evaluated based on answers to an evaluation framework containing 32 questions reflecting whether and to what extent the PVA study adhered to published PVA guidelines or contained important PVA components. All measures of PVA quality were generally lower for studies based on generic programs. Conservation status of the species did not affect any measure of PVA quality, but PVAs published in high IF journals were of higher quality. Quality generally declined over time, suggesting the quantitative literacy of PVA practitioners has not increased over time or that PVAs developed by unskilled users are being published in peer-reviewed journals. Only 18.1% of studies were of high quality (score > 75%), which is troubling because poor-quality PVAs could misinform conservation decisions. We call for increased scrutiny of PVAs by journal editors and reviewers. Our evaluation framework can be used for this purpose. Because poor-quality PVAs continue to be published, we recommend caution while using PVA results in conservation decision making without thoroughly assessing the PVA quality. El análisis de viabilidad poblacional (AVP) es útil para el manejo de especies en peligro. La gama de aplicaciones incluye el diseño de la investigación, la valoración de amenazas y el desarrollo de marcos de trabajo para el manejo. Ya que los AVP son de suma importancia, es esencial que sean rigorosos y se adhieran a las directrices aceptadas por la mayoría; sin embargo, rara vez se examina. la calidad de los AVP publicados Evaluamos la calidad de 160 AVP para 144 especies de aves y mamíferos publicados en revistas con revisión por pares desde 1990 hasta 2017. Nuestra hipotesis consistió en que la calidad del AVP sería más baja con programas genéricos que con programas hechos a la medida; sería más alta para los programas desarrollados para especies en peligro; la calidad cambiaría con el tiempo; y la calidad sería más alta para los AVP publicados en revistas con un alto factor de impacto (VI). Cada estudio que incluimos fue evaluado con base en las respuestas a un marco de trabajo de evaluación que contenía 32 preguntas, las cuales reflejaban si y cuánto se adherían los AVP a las directrices publicadas para los AVP o si contenía componentes importantes de AVP. Todas las medidas de la calidad de los AVP fueron generalmente más bajas para los estudios basados en programas genéricos. El estado de conservación de las especies no afectó ninguna de las medidas de la calidad de los AVP, pero aquellos publicados en revistas con un VI alto tuvieron una mayor calidad. La calidad, en general, declinó con el tiempo, lo que sugiere que el alfabetismo cuantitativo de quienes practican los AVP no ha incrementado con el tiempo o que se están publicando AVP desarrollados por usuarios con poca práctica en revistas con revisión por pares. Sólo el 18.1% de los estudios fue de calidad alta (puntaje > 75%), lo cual es preocupante porque los AVP de baja calidad podrían mal informar las decisiones de conservación. Pedimos un incremento en el escrutinio de los AVP por parte de los editores y revisores. Nuestro marco de trabajo de evaluación puede usarse para este propósito. Ya que todavía se publican AVP con baja calidad, recomendamos que se tomen precauciones cuando se usen los resultados de un AVP en la toma de decisiones de conservación sin evaluar minuciosamente la calidad de dicho estudio. 种群生存力分析 (population viability analysis, PVA) 是濒危物种管理的有效工具, 其应用笵围包括研究设 计 、 威胁评估及管理框架开发等 。 鉴 于 PVA 分析的重要性, 它们应当确保严谨 、 遵守普遍接受的准则, 然而,已 发表的 PVA 分析的质量却很少得到评估 。 本研究评估了 1990 至 2017 年间在同行评议期刊上发表的针对 144 种 鸟类及哺乳动物的 160 项 PVA 分析的质量 。 我们假设自行设定程序的 PVA 质量应比使用通用程序的更高;针对 濒危物种的 PVA 质量更高; PVA 质量随时间变化;发表在高影响因子期刊上的 PVA 质量更高 。 我们基于包含三 十二个问题的评估框架评估了每项纳入分析的研究,这些问题反映了 PVA 研究是否及在多大程度上遵守了已发 布 的 PVA 指南或包含了重要的 PVA 组成部分 。 结果表明, 使用通用程序的研究的 PVA 质量在所有指标上都较 低, 物种的濒危情况没有影响 PVA 质量,而发表在高影响因子的斯刊上的 PVA 质量更高 。 此外, PVA 质量普遍 随时间推移而下降, 这 表 明 PVA 实践者的定量推理能力没有与时倶进,或是同行评议斯刊上发表了非熟练使用 者开发的 PVA 研究 。 我们认为只有 18.1% 的研究属于高质量研究 ( 评分 >75%), 这个结果十分令人担忧,因为低 质量的 PVA 分析可能会误导保护决策 。 因此, 我们呼吁斯刊编辑和审稿人加强对 PVA 分析的审查,而我们的评 估框架就可以用于该目的 。 由于低质量的 PVA 还在持续发表,我们建议在保护决策中应谨慎使用未经彻底评估 质量的 PVA 結果 。

Ex situ conservation tools, such as captive breeding for reintroduction, are considered a last resort to recover threatened or endangered species, but they may also help reduce anthropogenic threats where it is difficult or impossible to address them directly. Headstarting, or captive rearing of eggs or neonate animals for subsequent release into the wild, is controversial because it treats only a symptom of a larger conservation problem; however, it may provide a mechanism to address multiple threats, particularly near population centers. We conducted a population viability analysis of Australia's most widespread freshwater turtle, Chelodina longicollis, to determine the effect of adult roadkill (death by collision with motor vehicles), which is increasing, and reduced recruitment through nest predation from introduced European red foxes (Vulpes vulpesj. We also modeled management scenarios to test the effectiveness of headstarting, fox management, and measures to reduce mortality on roads. Only scenarios with headstarting from source populations eliminated all risks of extinction and allowed population growth. Small increases in adult mortality (2%) had the greatest effect on population growth and extinction risk. Where threats simultaneously affected other life-history stages (e.g., recruitment), eliminating harvest pressures on adult females alone did not eliminate the risk of population extinction. In our models, one source population could supply enough hatchlings annually to supplement 25 other similar-sized populations such that extinction was avoided. Based on our results, we believe headstarting should be a primary tool for managing freshwater turtles for which threats affect multiple life-history stages. We advocate the creation of source populations for managing freshwater turtles that are greatly threatened at multiple life-history stages, such as depredation of eggs by invasive species and adult mortality via roadkill. Las herramientas de conservación ex situ, como la crianza en cautiverio para la reintroducción, son consideradas como el último recurso para recuperar a las especies amenazadas o en peligro, pero también pueden ayudar a reducir las amenazas antropogénicas en donde es difícil o imposible tratarlas directamente. El inicio con ventaja, o la crianza en cautiverio de huevos o animales neonatos para su liberación subsecuente a lá vida libre, es controversial porque solamente trata un síntoma de un problema mayor de la conservación; sin embargo, puede proporcionar un mecanismo para lidiar con múltiples amenazas, particularmente cerca de los centros poblacionales. Realizamos un análisis de viabilidad poblacional con la tortuga de agua dulce con mayor distribución en Australia, Chelodiina longicollis, para determinar el efecto de los atropellamientos de adultos (muerte por colisión con automóviles)，los cuales son cada vez más frecuentes，y redujimos el reclutamiento por medio de la depredación de nidos realizada por los zorros rojos Europeos introducidos (Yulpes vulpes). También modelamos escenarios de manejo para evaluar la efectividad del inicio con ventaja, el manejo de los zorros y las medidas para reducir la mortalidad en los caminos. Sólo los escenarios con inicio con ventaja a partir de poblaciones fuente eliminaron todos los riesgos de extinción y permitieron el crecimiento de la población. Los pequeños incrementos en la mortalidad adulta (2%) tuvieron el mayor efecto sobre el crecimiento poblacionaly el riesgo de extinción. En donde las amenazas afectaron simultáneamente a otras etapas de la ontogenia (p. ej.: el reclutamiento)，sólo controlar las presiones de cosecha sobre las hembras no eliminó el riesgo de extinción de la población. En nuestros modelos, una población fuente pudo proporcionar suficientes crías para abastecer a otras 25 poblaciones de tamaño similar de tal forma que se evitó la extinción. Con base en nuestros resultados, creemos que el inicio con ventaja debería ser una herramienta primaria para el manejo de tortugas de agua dulce para las cuales las amenazas afectan a múltiples etapas de la ontogenia. Proponemos la creación de poblaciones fuente para el manejo de tortugas de agua dulce que están enormemente amenazadas durante varias etapas de su historia de vida, como la depredación de los huevos por especies invasoras o la mortalidad adulta por atropellamientos.

Uses population viability analyses (PVA) to calculate the net effects of ecotourism on expected time to extinction, in the presence of other anthropogenic threats such as poaching, primary industries and habitat loss, for one or more subpopulations of the threatened species : orangutan, hoolock gibbon, golden lion tamarin, cheetah, African wild dog, New Zealand sealion, great green macaw, Egyptian vulture, and African penguin. Source: National Library of New Zealand Te Puna Matauranga o Aotearoa, licensed by the Department of Internal Affairs for re-use under the Creative Commons Attribution 3.0 New Zealand Licence.

Individual and interactive effects of changing climate and shifting fire regimes are influencing many plant species across the globe. Climate change will likely have significant impacts on plant population viability over time by altering environmental conditions and wildfire regimes as well as influencing species demographic traits. However, the outcomes of these complex interactions for different plant functional types under future climate conditions have been rarely examined. We used a proof‐of‐concept case‐study approach to model multiple plant species across two functional plant types, obligate seeder and facultative resprouter, to examine the interactive effects of demographic shifts and fire regime change on population persistence across two landscapes of over 7000 km2 in temperate southeastern Australia. Our approach involves a novel combination of a fire regime simulation tool with a spatially explicit population viability analysis model. We simulated fire regimes under six different future climates representing different temperature and precipitation shifts and combined them with 16 hypothetical plant demographic change scenarios, characterised by changes to individual or multiple plant demographic processes. Plant populations were more likely to decline or become extinct due to changes in demographic processes than in the fire regime alone. Although both functional types were vulnerable to climate‐induced changes in demography, obligate seeder persistence was also negatively influenced by future fire regimes characterised by shorter fire intervals. Integrating fire regime simulations with spatially explicit population viability analyses increased our capacity to identify those plant functional types most at risk of extinction, and why, as fire regimes change with climate change. This flexible framework is a first step in exploring the complex interactions that will determine plant viability under changing climates and will improve research and fire management prioritisation for species into the future.

The viability of populations can be quantified with several measures, such as the probability of extinction, the mean time to extinction, or the population size. While conservation management decisions can be based on these measures, it has not yet been explored systematically if different viability measures rank species and scenarios similarly and if one viability measure can be converted into another to compare studies. To address this challenge, we conducted a quantitative comparison of eight viability measures based on the simulated population dynamics of more than 4500 virtual species. We compared (a) the ranking of scenarios based on different viability measures, (b) assessed direct correlations between the measures, and (c) explored if parameters in the simulation models can alter the relationship between pairs of viability measures. We found that viability measures ranked species similarly. Despite this, direct correlations between the different measures were often weak and could not be generalized. This can be explained by the loss of information due to the aggregation of raw data into a single number, the effect of model parameters on the relationship between viability measures, and because distributions, such as the probability of extinction over time, cannot be ranked objectively. Similar scenario rankings by different viability measures show that the choice of the viability metric does in many cases not alter which population is regarded more viable or which management option is the best. However, the more two scenarios or populations differ, the more likely it becomes that different measures produce different rankings. We thus recommend that PVA studies publish raw simulation data, which not only describes all risks and opportunities to the reader but also facilitates meta‐analyses of PVA studies. Population viability was ranked similarly in a quantitative comparison of eight measures of population viability derived from simulated population dynamics of more than 4500 virtual species. However, direct correlations between measures were weak and could not be generalized. We thus recommend that population‐viability analyses publish raw simulation data to support robust comparisons of population viabilities.

Population viability analysis (PVA) has become a basic tool of current conservation practice. However, if not accounted for properly, the uncertainties inherent to PVA predictions can decrease the reliability of this type of analysis. In the present study, we performed a PVA of the whole western European population (France, Portugal, and Spain) of the endangered Bonelli's Eagle ( Aquila fasciata ), in which we thoroughly explored the consequences of uncertainty in population processes and parameters on PVA predictions. First, we estimated key vital rates (survival, fertility, recruitment, and dispersal rates) using monitoring, ringing, and bibliographic data from the period 1990-2009 from 12 populations found throughout the studied geographic range. Second, we evaluated the uncertainty about model structure (i.e., the assumed processes that govern individual fates and population dynamics) by comparing the observed growth rates of the studied populations with model predictions for the same period. Third, using the model structures suggested in the previous step, we assessed the viability of both the local populations and the overall population. Finally, we analyzed the effects of model and parameter uncertainty on PVA predictions. Our results strongly support the idea that all local populations in western Europe belong to a single, spatially structured population operating as a source-sink system, whereby the populations in the south of the Iberian Peninsula act as sources and, thanks to dispersal, sustain all other local populations, which would otherwise decline. Predictions regarding population dynamics varied considerably, and models assuming more constrained dispersal predicted more pessimistic population trends than models assuming greater dispersal. Model predictions accounting for parameter uncertainty revealed a marked increase in the risk of population declines over the next 50 years. Sensitivity analyses indicated that adult and pre-adult survival are the chief vital rates regulating these populations, and thus, the conservation efforts aimed at improving these survival rates should be strengthened in order to guarantee the long-term viability of the European populations of this endangered species. Overall, the study provides a framework for the implementation of multi-site PVAs and highlights the importance of dispersal processes in shaping the population dynamics of long-lived birds distributed across heterogeneous landscapes.

Aim Reintroducing carnivores is a widely used approach to restore the natural integrity of ecosystems. Species distribution models (SDMs) and connectivity analyses are valuable tools for planning reintroductions and identifying release sites but are rarely combined. We propose a new framework combining SDMs, connectivity modelling and individual‐based models (IBMs) to assess the feasibility of various reintroduction scenarios. As a case study, we applied this framework to plan a potential reintroduction of the Eurasian lynx (Lynx lynx) to the Apennines by: (i) assessing niche overlap between potential source and target populations; (ii) integrating habitat suitability and connectivity to select release sites and (iii) evaluating reintroduction outcomes through IBMs. Location Apennines, Peninsular Italy. Methods We combined niche overlap analysis, ensembles of fine‐tuned SDMs and circuit‐theory techniques to model connectivity. Then, we integrated suitability and connectivity predictions within a GIS environment to identify the optimal release sites under different scenarios. Finally, we used IBMs to assess population viability, site occupancy and dispersal. Results Niche overlap suggested that the Carpathian lynx populations may serve as a valid reintroduction source. Integrating habitat and connectivity models highlighted the most functional sites in the Central (CA) and Northern Apennines (NA). A scenario with individuals released in both CA and NA did not outperform the single‐area scenarios. Releasing individuals only in CA showed long‐term feasibility but a higher risk of isolation, while release only in NA would not result in viable populations in the long term, despite closer proximity to suitable areas in the Alps. Main Conclusions Our framework can help practitioners with integrating functional connectivity within the selection of release sites for species reintroductions. We recommend incorporating demography, as well as dispersal and settlement phases, when evaluating reintroduction scenarios. This approach identifies critical mortality areas, predicts population size, site occupancy and connectivity and enhances decision‐making for successful reintroductions.