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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 。

Waking up to global warming Climate change affects the timing of regular events of plant and animal life, such as budding, migration and hibernation, as well as population dynamics and morphology. It is difficult to monitor all these interacting factors at once, but an extended life-history study of a hibernating mammal — a yellow-bellied marmot ( Marmota flaviventris ) population in a subalpine habitat in the Upper East River Valley, Colorado — provides data suited to the task. Climate change over the period 1976–2008 has caused earlier emergence from hibernation, lengthening the animals' growing season so that they are now heavier when they start to hibernate. At the same time, the fitness of large individuals has increased, leading to a rapid increase in population size. As Marcel Visser explains in the accompanying News & Views, the major challenge in climate-change ecology is to predict the impact of future climate change on populations. This work on marmots provides the type of data needed to achieve that aim. Climate change can affect the phenology, population dynamics and morphology of species, but it is difficult to study all these factors and their interactions at once. Using long-term data for individual yellow-bellied marmots, these authors show that climate change has increased the length of the marmot growing season, leading to a gradual increase in individual size. It has simultaneously increased the fitness of large individuals, leading to a rapid increase in population size. Environmental change has altered the phenology, morphological traits and population dynamics of many species 1 , 2 . However, the links underlying these joint responses remain largely unknown owing to a paucity of long-term data and the lack of an appropriate analytical framework 3 . Here we investigate the link between phenotypic and demographic responses to environmental change using a new methodology and a long-term (1976–2008) data set from a hibernating mammal (the yellow-bellied marmot) inhabiting a dynamic subalpine habitat. We demonstrate how earlier emergence from hibernation and earlier weaning of young has led to a longer growing season and larger body masses before hibernation. The resulting shift in both the phenotype and the relationship between phenotype and fitness components led to a decline in adult mortality, which in turn triggered an abrupt increase in population size in recent years. Direct and trait-mediated effects of environmental change made comparable contributions to the observed marked increase in population growth. Our results help explain how a shift in phenology can cause simultaneous phenotypic and demographic changes, and highlight the need for a theory integrating ecological and evolutionary dynamics in stochastic environments 4 , 5 .

Cancer is a disease of single cells that expresses itself at the population level. The striking similarities between initiation and growth of tumors and dynamics of biological populations, and between metastasis and ecological invasion and community dynamics suggest that oncology can benefit from an ecological perspective to improve our understanding of cancer biology. Tumors can be viewed as complex, adaptive, and evolving systems as they are spatially and temporally heterogeneous, continually interacting with each other and with the microenvironment and evolving to increase the fitness of the cancer cells. We argue that an eco‐evolutionary perspective is essential to understand cancer biology better. Furthermore, we suggest that ecologically informed therapeutic approaches that combine standard of care treatments with strategies aimed at decreasing the evolutionary potential and fitness of neoplastic cells, such as disrupting cell‐to‐cell communication and cooperation, and preventing successful colonization of distant organs by migrating cancer cells, may be effective in managing cancer as a chronic condition. We argue that an eco‐evolutionary perspective is essential to understand cancer biology better. Furthermore, we suggest that ecologically‐informed therapeutic approaches that combine standard of care treatments with strategies aimed at decreasing the evolutionary potential and fitness of neoplastic cells, such as disrupting cell‐to‐cell communication and cooperation and preventing successful colonization of distant organs by migrating cancer cells, may be effective in managing cancer as a chronic condition.

Genetic rescue—an increase in population fitness following the introduction of new alleles—has been proven to ameliorate inbreeding depression in small, isolated populations, yet is rarely applied as a conservation tool. A lingering question regarding genetic rescue in wildlife conservation is how long beneficial effects persist in admixed populations. Using data collected over 40 years from 1192 endangered Florida panthers ( Puma concolor coryi ) across nine generations, we show that the experimental genetic rescue implemented in 1995—via the release of eight female pumas from Texas—alleviated morphological, genetic, and demographic correlates of inbreeding depression, subsequently preventing extirpation of the population. We present unequivocal evidence, for the first time in any terrestrial vertebrate, that genetic and phenotypic benefits of genetic rescue remain in this population after five generations of admixture, which helped increase panther abundance (> fivefold) and genetic effective population size (> 20-fold). Additionally, even with extensive admixture, microsatellite allele frequencies in the population continue to support the distinctness of Florida panthers from other North American puma populations, including Texas. Although threats including habitat loss, human-wildlife conflict, and infectious diseases are challenges to many imperiled populations, our results suggest genetic rescue can serve as an effective, multi-generational tool for conservation of small, isolated populations facing extinction from inbreeding.

Understanding mechanisms underlying coexistence among potential competitors, and between predators and prey, is a persistent challenge in community ecology. Using 6 years (2013–2018) of camera‐trapping data and species interaction models, we investigated the spatiotemporal patterns of inter‐ and intra‐guild interspecific interactions in a diverse terrestrial mammalian community in Pakke Wildlife Sanctuary and Tiger Reserve (PTR), Northeast India. We found no evidence of spatial interaction among apex predators (tiger Panthera tigris, leopard Panthera pardus, and dhole Cuon alpinus). However, dholes temporally separated themselves from tigers and leopards. Among small carnivores, marbled cat (Pardofelis marmorata) and leopard cat (Prionailurus bengalensis) exhibited temporal separation, whereas leopard cat overlapped spatially and temporally with other small carnivores. Herbivores exhibited neither spatial nor temporal separation with each other. All apex predators exhibited diel activity and space‐use patterns to overlap with their preferred prey. Our results suggest that the assembly of the diverse mammalian community of PTR is a complex process, and coexistence among potential competitors, and predators and prey is likely facilitated by several mechanisms including spatial and temporal segregation, and potentially dietary separation.

Cyclic fluctuations in abundance exhibited by some mammalian populations in northern habitats (“population cycles”) are key processes in the functioning of many boreal and tundra ecosystems. Understanding population cycles, essentially demographic processes, necessitates discerning the demographic mechanisms that underlie numerical changes. Using mark–recapture data spanning five population cycles (1977–2017), we examined demographic mechanisms underlying the 9–10-yr cycles exhibited by snowshoe hares (Lepus americanus Erxleben) in southwestern Yukon, Canada. Snowshoe hare populations always decreased during winter and increased during summer; the balance between winter declines and summer increases characterized the four, multiyear cyclic phases: increase, peak, decline, and low. Little or no recruitment occurred during winter, but summer recruitment varied markedly across the four phases with the highest and lowest recruitment observed during the increase and decline phase, respectively. Population crashes during the decline were triggered by a substantial decline in winter survival and by a lack of subsequent summer recruitment. In contrast, initiation of the increase phase was triggered by a twofold increase in summer recruitment abetted secondarily by improvements in subsequent winter survival. We show that differences in peak density across cycles are explained by differences in overall population growth rate, amount of time available for population growth to occur, and starting population density. Demographic mechanisms underlying snowshoe hare population cycles were consistent across cycles in our study site but we do not yet know if similar demographic processes underlie population cycles in other northern snowshoe hare populations.

Climate change is slowly influencing boreal forest ecosystems, with rising temperatures and altered snow conditions driving phenological shifts in many plant and animal species. Using 7 years (2016–2022) of camera trap data from the Kluane Lake region, Yukon, we quantified seasonal moulting phenology and coat-colour mismatch in snowshoe hares. Autumn moult started between 28 September and 3 October and completed between 5 and 11 November, with the mean moult duration ranging from 36 to 43 days. Spring moult initiated between 12 April and 27 April and completed between 16 May and 27 May, with moult duration ranging from 24 to 38 days. Contrary to our expectations, there was no evidence of delayed or advanced moulting phenology over this 7-year period. The mismatch between snowshoe hare coat colour and background showed an increasing trend and average whiteness of the snowshoe hare coat in autumn declined. Temperature and snow variables influenced various aspects of seasonal moulting phenology, in some cases in the opposite direction. Long-term studies utilizing intrinsic and high-resolution microclimatic data and behavioural observations are needed to understand how moulting phenology and mismatch affect predator–prey dynamics and snowshoe hare demography and population dynamics as climate change continues.

Characterizing population dynamics in heterogeneous environments requires comprehensive long‐term data. We monitored seven small mammals in replicated sites in a semiarid Chilean thorn‐scrub habitat over 30 years using monthly capture–mark–recapture (CMR) sampling. We applied a superpopulation CMR modeling framework to examine the following: (i) How do population sizes and demographic parameters vary seasonally and over time? and (ii) Are there commonalities in the variation of those parameters either seasonally or annually? Capture probabilities among four “core” species ( Octodon degus , Phyllotis darwini , Abrothrix olivacea , and Thylamys elegans ) varied strongly over time, as did apparent survival among years and rainfall seasons, with individuals generally experiencing higher survival during the wet season. Recruitment measures also showed strong annual and seasonal variation, with higher numbers in wet seasons and years. Capture probability in three “opportunistic” species ( Abrocoma bennettii , Abrothrix longipilis , and Oligoryzomys longicaudatus ) varied over time, as did survival and recruitment across rainfall or reproductive seasons. As predicted, annual and seasonal variation in rainfall strongly influenced the survival and recruitment of most species, and their populations increased rapidly following rainfall events. Unsurprisingly, core species shared similar overall responses to environmental drivers; opportunistic species responded differently to seasonal or annual variation in rainfall, perhaps reflecting their origins in non‐thorn‐scrub habitat. Finally, for all species, population size correlated more strongly with the number of recruits than with survival, suggesting that the former has a greater influence on the dynamics of our study populations. This study provides the first insight into the demography of the entire small mammal community at our study site, and in particular, the demography of A. bennettii , A. longipilis , and O. longicaudatus from semiarid habitat. Our results, based on the longest time series in South America, provide comprehensive demographic information on a diverse small mammal community, and offer novel insight into community‐level response to changing climate.

The relative importance of life-history variables to population growth rate (λ) has substantial consequences for the study of life-history evolution and for the dynamics of biological populations. Using life-history data for 142 natural populations of mammals, we estimated the elasticity of λ to changes in age at maturity (α), age at last reproduction (ω), juvenile survival (Pj), adult survival (Pa), and fertility (F). Elasticities were then used to quantify the relative importance of α, ω, Pj, Pa, and F to λ and to test theoretical predictions regarding the relative influence on λ of changes in life-history variables. Neither α nor any other single life-history variable had the largest relative influence on λ in the majority of the populations, and this pattern did not change substantially when effects of phylogeny and body size were statistically removed. Empirical support for theoretical predictions was poor at best. However, analyses of elasticities on the basis of the magnitude (F) and onset (α) of reproduction revealed that α, followed by F, had the largest relative influence on λ in populations characterized by early maturity and high reproductive rates, or when \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $$F/ \\alpha > 0.60$$ \\end{document} . When maturity was delayed and reproductive rates were low, or when \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $$F/ \\alpha < 0.15$$ \\end{document} , survival rates were overwhelmingly most influential, and reproductive parameters (α and F) had little relative influence on λ. Population dynamic consequences of likely responses of biological populations to perturbations in life-history variables are examined, and predictions are made regarding the numerical dynamics of age-structured populations on the basis of values of the F/α ratio.

Population density around the natal site is often invoked as an explanation for variation in dispersal distance, with the expectation that competition for limiting resources, coupled with increased intra-specific aggression at high densities, should drive changes in dispersal distances. However, tests of the density-dependent dispersal hypothesis in long-lived vertebrates have yielded mixed results. Furthermore, conclusions from dispersal studies may depend on the spatial and temporal scales at which density and dispersal patterns are examined, yet multi-scale studies of dispersal are rare. Here, we present the findings of a long-term study examining factors influencing natal dispersal distances for the non-migratory population of Peregrine Falcons (Falco peregrinus) in the British Isles across distinct spatial and temporal scales. Our smallest scale study included Peregrines ringed as nestlings and subsequently recaptured alive in south Scotland–north England, an area that was intensively studied during the time periods 1974–1982 and 2002–2016. Second, we examined dispersal patterns of birds ringed as nestlings in south Scotland–north England, but subsequently recaptured alive or recovered dead anywhere in the British Isles. Finally, we examined the natal dispersal patterns for Peregrines ringed and recaptured or recovered anywhere in the British Isles from 1964 to 2016. Consistent with prior findings, females dispersed farther than males across all scales. However, the patterns of dispersal were strongly scale dependent. Specifically, we found a lack of a discernible relationship between index of density and dispersal distance in the limited study area, but when region-wide recaptures and recoveries were included in the analyses, a negative relationship was revealed. Our results suggest that conclusions of dispersal studies may be scale dependent, highlighting the importance of spatial and temporal scales in examining and interpreting the relationship between population density and dispersal patterns.