Golden lion tamarin metapopulation dynamics five years after heavy losses to yellow fever.

The golden lion tamarin (GLT) is an Endangered primate endemic to Brazil's lowland Atlantic Forest. After centuries of deforestation and capture for the pet trade, only a few hundred individuals survived, all in isolated forest fragments 85 km from Rio de Janeiro city. Intensive conservation actions, including reintroduction of zoo-born tamarins, increased numbers to about 3700 in 2014. The most severe yellow fever epidemic/epizootic in Brazil in 80 years reduced two of the largest GLT populations by over 90%. Herein we report the results of a 2023 survey of GLTs designed to examine the dynamics of population recovery following yellow fever. Results indicate that populations hard hit by yellow fever are recovering due in part to immigration from adjacent forest fragments. No local extirpations were observed. About 4800 GLTs live in the survey area. This represents a 31% increase since the baseline survey completed in 2014. Two factors explain most of the increase: four large areas that had no GLTs or very low-density populations in 2014 are now at moderate density (three areas) or low density (one area), explaining 71% of overall increase since 2014. Increase in forest area within our survey area may explain up to 16% of the increase in GLT numbers since 2014. Results of computer simulations suggest that strengthening forest connectivity will facilitate metapopulation resilience in the face of mortality factors such as yellow fever.

The genetic status and rescue measure for a geographically isolated population of Amur tigers.

The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population's genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.

Predicting the fundamental thermal niche of ectotherms.

Climate warming is predicted to increase mean temperatures and thermal extremes on a global scale. Because their body temperature depends on the environmental temperature, ectotherms bear the full brunt of climate warming. Predicting the impact of climate warming on ectotherm diversity and distributions requires a framework that can translate temperature effects on ectotherm life-history traits into population- and community-level outcomes. Here we present a mechanistic theoretical framework that can predict the fundamental thermal niche and climate envelope of ectotherm species based on how temperature affects the underlying life-history traits. The advantage of this framework is twofold. First, it can translate temperature effects on the phenotypic traits of individual organisms to population-level patterns observed in nature. Second, it can predict thermal niches and climate envelopes based solely on trait response data and, hence, completely independently of any population-level information. We find that the temperature at which the intrinsic growth rate is maximized exceeds the temperature at which abundance is maximized under density-dependent growth. As a result, the temperature at which a species will increase the fastest when rare is lower than the temperature at which it will recover from a perturbation the fastest when abundant. We test model predictions using data from a naturalized-invasive interaction to identify the temperatures at which the invasive can most easily invade the naturalized's habitat and the naturalized is most likely to resist the invasive. The framework is sufficiently mechanistic to yield reliable predictions for individual species and sufficiently broad to apply across a range of ectothermic taxa. This ability to predict the thermal niche before a species encounters a new thermal environment is essential to mitigating some of the major effects of climate change on ectotherm populations around the globe.

120-years of ecological monitoring data shows that the risk of overhunting is increased by environmental degradation for an isolated marine mammal population: The Baltic grey seal.

The Baltic Sea is home to a genetically isolated and morphologically distinct grey seal population. This population has been the subject of 120-years of careful documentation, from detailed records of bounty statistics to annual monitoring of health and abundance. It has also been exposed to a range of well-documented stressors, including hunting, pollution and climate change. To investigate the vulnerability of marine mammal populations to multiple stressors, data series relating to the Baltic grey seal population size, hunt and health were compiled, vital demographic rates were estimated, and a detailed population model was constructed. The Baltic grey seal population fell from approximately 90,000 to as few as 3000 individuals during the 1900s as the result of hunting and pollution. Subsequently, the population has recovered to approximately 55,000 individuals. Fertility levels for mature females have increased from 9% in the 1970s to 86% at present. The recovery of the population has led to demands for increased hunting, resulting in a sudden increase in annual quotas from a few hundred to 3550 in 2020. Simultaneously, environmental changes, such as warmer winters and reduced prey availability due to overfishing, are likely impacting fecundity and health. Future population development is projected for a range of hunting and environmental stress scenarios, illustrating how hunting, in combination with environmental degradation, can lead to population collapse. The current combined hunting quotas of all Baltic Nations caused a 10% population decline within three generations in 100% of simulations. To enable continued recovery of the population, combined annual quotas of less than 1900 are needed, although this quota should be re-evaluated annually as monitoring of population size and seal health continues. Sustainable management of long-lived slowly growing species requires an understanding of the drivers of population growth and the repercussions of management decisions over many decades. The case of the Baltic grey seal illustrates how long-term ecological time series are pivotal in establishing historical baselines in population abundance and demography to inform sustainable management.

Inferring stability and persistence in the vaginal microbiome: A stochastic model of ecological dynamics.

The interplay of stochastic and ecological processes that govern the establishment and persistence of host-associated microbial communities is not well understood. Here we illustrate the conceptual and practical advantages of fitting stochastic population dynamics models to multi-species bacterial time series data. We show how the stability properties, fluctuation regimes and persistence probabilities of human vaginal microbial communities can be better understood by explicitly accommodating three sources of variability in ecological stochastic models of multi-species abundances: 1) stochastic biotic and abiotic forces, 2) ecological feedback and 3) sampling error. Rooting our modeling tool in stochastic population dynamics modeling theory was key to apply standardized measures of a community's reaction to environmental variation that ultimately depends on the nature and intensity of the intra-specific and inter-specific interaction strengths. Using estimates of model parameters, we developed a Risk Prediction Monitoring (RPM) tool that estimates temporal changes in persistence probabilities for any bacterial group of interest. This method mirrors approaches that are often used in conservation biology in which a measure of extinction risks is periodically updated with any change in a population or community. Additionally, we show how to use estimates of interaction strengths and persistence probabilities to formulate hypotheses regarding the molecular mechanisms and genetic composition that underpin different types of interactions. Instead of seeking a definition of "dysbiosis" we propose to translate concepts of theoretical ecology and conservation biology methods into practical approaches for the management of human-associated bacterial communities.

Parental effects on offspring sex ratio in the Numbat (Myrmecobius fasciatus): does captivity influence paternal sex allocation?

Sex allocation theories predict that under different ecological conditions the production of sons and daughters will affect parental fitness differently. Skewed offspring sex ratios often occur under captive conditions where individuals are exposed to nutritional and social conditions that differ from nature. Here, we analyzed 29 years of offspring sex ratio data from a captive population of an endangered marsupial, the Numbat (Myrmecobius fasciatus). We partitioned variation in offspring sex ratio based on parental origin (captive- vs. wild-bred), parental weight, maternal age, and maternal reproductive history. Our analyses revealed no effect of parental weight or maternal origin on offspring sex ratio-however, there was a significant effect of paternal origin. Data visualization indicated that captive-bred males tended to produce male-biased litters. We discuss the result in relation to recent studies that have shown that male mammals have the capacity to be arbiters of sex allocation and highlight candidate mechanisms, but consider it with caution due to the small sample size from which the result was derived. We performed a population viability analysis (PVA) to explore the potential impact of a sex ratio skew on the sustainability of the captive Numbat population under hypothetical scenarios. Our PVA revealed that supplementation with wild individuals is critical to the persistence of the captive Numbat population and that a biased sex ratio will lead to extinction of the captive colony under certain conditions. Overall, our study demonstrates that covert sex ratio skews can persist undetected in captive populations, which have the potential to become impactful and compromise population sustainability under changed management processes.

Extinction risks and mitigation for a megaherbivore, the giraffe, in a human-influenced landscape under climate change.

Megaherbivores play "outsized" roles in ecosystem functioning but are vulnerable to human impacts such as overhunting, land-use changes, and climate extremes. However, such impacts-and combinations of these impacts-on population dynamics are rarely examined using empirical data. To guide effective conservation actions under increasing global-change pressures, we developed a socially structured individual-based model (IBM) using long-term demographic data from female giraffes (Giraffa camelopardalis) in a human-influenced landscape in northern Tanzania, the Tarangire Ecosystem. This unfenced system includes savanna habitats with a wide gradient of anthropogenic pressures, from national parks, a wildlife ranch and community conservation areas, to unprotected village lands. We then simulated and projected over 50 years how realistic environmental and land-use management changes might affect this metapopulation of female giraffes. Scenarios included: (1) anthropogenic land-use changes including roads and agricultural/urban expansion; (2) reduction or improvement in wildlife law enforcement measures; (3) changes in populations of natural predators and migratory alternative prey; and (4) increases in rainfall as predicted for East Africa. The factor causing the greatest risk of rapid declines in female giraffe abundance in our simulations was a reduction in law enforcement leading to more poaching. Other threats decreased abundances of giraffes, but improving law enforcement in both of the study area's protected areas mitigated these impacts: a 0.01 increase in giraffe survival probability from improved law enforcement mitigated a 25% rise in heavy rainfall events by increasing abundance 19%, and mitigated the expansion of towns and blockage of dispersal movements by increasing abundance 22%. Our IBM enabled us to further quantify fine-scale abundance changes among female giraffe social communities, revealing potential source-sink interactions within the metapopulation. This flexible methodology can be adapted to test additional ecological questions in this landscape, or to model populations of giraffes or other species in different ecosystems.

BatTool: projecting bat populations facing multiple stressors using a demographic model.

Bats provide ecologically and agriculturally important ecosystem services but are currently experiencing population declines caused by multiple environmental stressors, including mortality from white-nose syndrome and wind energy development. Analyses of the current and future health and viability of these species may support conservation management decision making. Demographic modeling provides a quantitative tool for decision makers and conservation managers to make more informed decisions, but widespread adoption of these tools can be limited because of the complexity of the mathematical, statistical, and computational components involved in implementing these models. In this work, we provide an exposition of the BatTool R package, detailing the primary components of the matrix projection model, a publicly accessible graphical user interface ( https://rconnect.usgs.gov/battool ) facilitating user-defined scenario analyses, and its intended uses and limitations (Wiens et al., US Geol Surv Data Release 2022; Wiens et al., US Geol Surv Softw Release 2022). We present a case study involving wind energy permitting, weighing the effects of potential mortality caused by a hypothetical wind energy facility on the projected abundance of four imperiled bat species in the Midwestern United States.

EolPop, a R-shiny tool for quantifying the demographic impact of species exposed to fatalities: Application to bird collisions with wind turbines.

Quantifying the demographic impact of anthropogenic fatalities on animal populations is a key component of wildlife conservation. However, such quantification remains rare in environmental impact assessments (EIA) of large-infrastructure projects, partly because of the complexity of implementing demographic models. Providing user-friendly demographic tools is thus an important step to fill this gap. We developed an application called EolPop to run demographic simulations and assess population-level impacts of fatalities. This tool, freely available online, is easy to use and requires minimal input data from the user. As an output, it provides an estimate, with associated uncertainty, of the relative deficit in population size at a given time horizon. Because this impact metric is relative to a baseline scenario without fatalities, it is robust to uncertainties. We showcase the tool using examples on two species that are affected by collisions with wind turbines: Lesser kestrel (Falco naumanni) and Eurasian skylark (Alauda arvensis). After 30 years, the kestrel's population is expected to suffer a deficit of ca. 48%. In contrast, the impact on skylarks, which are already declining in France, is estimated to be fairly low (ca. 7%). EolPop aims at providing a robust quantification of the relative impact of fatalities. This tool was originally built for windfarm EIA, with a focus on birds, but it can be used to assess the demographic consequences of any type of fatalities on any species.

Mechanisms that can cause population decline under heavily skewed male-biased adult sex ratios.

While adult sex ratio (ASR) is a crucial component for population management, there is still a limited understanding of how its fluctuation affects population dynamics. To demonstrate mechanisms that hinder population growth under a biased ASR, we examined changes in reproductive success with ASR using a decapod crustacean exposed to female-selective harvesting. We examined the effect of ASR on the spawning success of females. A laboratory experiment showed that the number of eggs carried by females decreased as the proportion of males in the mating groups increased. Although the same result was not observed in data collected over 25 years in the wild, the negative effect of ASR was suggested when success in carrying eggs was considered as a spawning success. These results indicate that a surplus of males results in females failing to carry eggs, probably due to sexual coercion, and the negative effect of ASR can be detected at the population level only when the bias increases because failure in spawning success occurs in part of population. We experimentally examined how male-biased sex ratios affected the maintenance of genetic diversity in a population. The diversity of paternity in a clutch increased with the number of candidate fathers. However, over 50% of a clutch was fertilised by a single male regardless of the sex ratio, and the degree of diversity was less than half of the highest diversity expected in each mating group. We also experimentally examined the mating ability of males during the breeding season. The experiment showed that multiple mating by males could not compensate for the risk that their genotypes would be lost when multiple males competed for one female. These results suggest that a male-biased ASR could trigger a decline of genetic diversity in a population. We show that ASR skewed by female-selective harvesting decreases reproductive success not only of males that have few mating opportunities but also of females. We discuss that we may still underestimate the significance of ASR on population persistence due to the difficulty of revealing the effect of ASR.

Quantifying the impacts of predation by Great Black-backed Gulls Larus marinus on an Atlantic Puffin Fratercula arctica population: Implications for conservation management and impact assessments.

The management of predator-prey conflicts can be a key aspect of species conservation. For management approaches to be effective, a robust understanding of the predator-prey relationship is needed, particularly when both predator and prey are species of conservation concern. On the Isle of May, Firth of Forth, Scotland, numbers of breeding Great Black-backed Gulls Larus marinus, a generalist predator, have been increasing since the 1980s, which has led to increasing numbers of sympatrically breeding Atlantic Puffins Fratercula arctica being predated during the breeding season. This may have consequences for species management on the Isle of May and impact assessments of offshore windfarms in the wider Firth of Forth area. We used population viability analysis to quantify under what predation pressure the Atlantic Puffin population may decline and become locally extinct over a three-generation period. The predation level empirically estimated in 2017 (1120 Puffins per year) was not sufficient to drive a decline in the Puffin population. Rather, an increase to approximately 3000 Puffins per year would be required to cause a population decline, and >4000 to drive the population to quasi-extinction within 66 years. We discuss the likelihood of such a scenario being reached on the Isle of May, and we recommend that where predator-prey conflicts occur, predation-driven mortality should be regularly quantified to inform conservation management and population viability analyses associated with impact assessments.

Addressing the impact of canine distemper spreading on an isolated tiger population in northeast Asia.

The continuation of the isolated Amur tiger (Panthera tigris altaica) population living along the China-Russia border is facing serious challenges due to factors such as its small size (including 38 individuals) and canine distemper virus (CDV). We use a population viability analysis metamodel, which consists of a traditional individual-based demographic model linked to an epidemiological model, to assess options for controlling the impact of negative factors through domestic dog management in protected areas, increasing connectivity to the neighboring large population (including more than 400 individuals), and habitat expansion. Without intervention, under inbreeding depression of 3.14, 6.29, and 12.26 lethal equivalents, our metamodel predicted the extinction within 100 years is 64.4%, 90.6%, and 99.8%, respectively. In addition, the simulation results showed that dog management or habitat expansion independently will not ensure tiger population viability for the next 100 years, and connectivity to the neighboring population would only keep the population size from rapidly declining. However, when the above three conservation scenarios are combined, even at the highest level of 12.26 lethal equivalents inbreeding depression, population size will not decline and the probability of extinction will be <5.8%. Our findings highlight that protecting the Amur tiger necessitates a multifaceted synergistic effort. Our key management recommendations for this population underline the importance of reducing CDV threats and expanding tiger occupancy to its former range in China, but re-establishing habitat connectivity to the neighboring population is an important long-term objective.

Raising offspring increases ageing: Differences in senescence among three populations of a long-lived seabird, the Atlantic puffin.

Actuarial senescence, the decline of survival with age, is well documented in the wild. Rates of senescence vary widely between taxa, to some extent also between sexes, with the fastest life histories showing the highest rates of senescence. Few studies have investigated differences in senescence among populations of the same species, although such variation is expected from population-level differences in environmental conditions, leading to differences in vital rates and thus life histories. We predict that, within species, populations differing in productivity (suggesting different paces of life) should experience different rates of senescence, but with little or no sexual difference in senescence within populations of monogamous, monomorphic species where the sexes share breeding duties. We compared rates of actuarial senescence among three contrasting populations of the Atlantic puffin Fratercula arctica. The dataset comprised 31 years (1990-2020) of parallel capture-mark-recapture data from three breeding colonies, Isle of May (North Sea), Røst (Norwegian Sea) and Hornøya (Barents Sea), showing contrasting productivities (i.e. annual breeding success) and population trends. We used time elapsed since first capture as a proxy for bird age, and productivity and the winter North Atlantic Oscillation Index (wNAO) as proxies for the environmental conditions experienced by the populations within and outside the breeding season, respectively. In accordance with our predictions, we found that senescence rates differed among the study populations, with no evidence for sexual differences. There was no evidence for an effect of wNAO, but the population with the lowest productivity, Røst, showed the lowest rate of senescence. As a consequence, the negative effect of senescence on the population growth rate (λ) was up to 3-5 times smaller on Røst (Δλ = -0.009) than on the two other colonies. Our findings suggest that environmentally induced differences in senescence rates among populations of a species should be accounted for when predicting effects of climate variation and change on species persistence. There is thus a need for more detailed information on how both actuarial and reproductive senescence influence vital rates of populations of the same species, calling for large-scale comparative studies.

A comparison of population viability measures.

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.

Age Structure, Development and Population Viability of Banteng (Bos javanicus) in Captive Breeding for Ex-Situ Conservation and Reintroduction.

Captive breeding is important for ex-situ conservation and the future reintroduction of bovids that become extinct in the wild. The age structure, development, and viability of captive-bred bantengs (Bos javanicus) are important to sustain the long-term reintroduction program in Salakphra Wildlife Sanctuary (SWF) and other areas. This research conducted a long-term population viability analysis (PVA) using height, weight, body condition scores (BSC), age structure, and development in captivity for a sustainable reintroduction program of bantengs in Thailand. Monthly development photographs of 23 founder individuals (12 males and 11 females) were assessed by three banteng experts, two researchers, and three members of the general public. The assessments of weight and BCS were not significantly different among the three groups, while height was underestimated by the general public. The PVA showed that the time to reach the maximum population in a captive banteng program is dependent on the carrying capacity of the habitat. The reduction of a small banteng founder group by the reintroduction of animals into the wild can negatively affect the population growth of the captive group. This information can be used to maintain the population viability of bantengs and sustain ex-situ conservation and the reintroduction program in Thailand and elsewhere.

Demographic consequences of changes in environmental periodicity.

The fate of natural populations is mediated by complex interactions among vital rates, which can vary within and among years. Although the effects of random, among-year variation in vital rates have been studied extensively, relatively little is known about how periodic, nonrandom variation in vital rates affects populations. This knowledge gap is potentially alarming as global environmental change is projected to alter common periodic variations, such as seasonality. We investigated the effects of changes in vital-rate periodicity on populations of three species representing different forms of adaptation to periodic environments: the yellow-bellied marmot (Marmota flaviventer), adapted to strong seasonality in snowfall; the meerkat (Suricata suricatta), adapted to inter-annual stochasticity as well as seasonal patterns in rainfall; and the dewy pine (Drosophyllum lusitanicum), adapted to fire regimes and periodic post-fire habitat succession. To assess how changes in periodicity affect population growth, we parameterized periodic matrix population models and projected population dynamics under different scenarios of perturbations in the strength of vital-rate periodicity. We assessed the effects of such perturbations on various metrics describing population dynamics, including the stochastic growth rate, log λS . Overall, perturbing the strength of periodicity had strong effects on population dynamics in all three study species. For the marmots, log λS decreased with increased seasonal differences in adult survival. For the meerkats, density dependence buffered the effects of perturbations of periodicity on log λS . Finally, dewy pines were negatively affected by changes in natural post-fire succession under stochastic or periodic fire regimes with fires occurring every 30 years, but were buffered by density dependence from such changes under presumed more frequent fires or large-scale disturbances. We show that changes in the strength of vital-rate periodicity can have diverse but strong effects on population dynamics across different life histories. Populations buffered from inter-annual vital-rate variation can be affected substantially by changes in environmentally driven vital-rate periodic patterns; however, the effects of such changes can be masked in analyses focusing on inter-annual variation. As most ecosystems are affected by periodic variations in the environment such as seasonality, assessing their contributions to population viability for future global-change research is crucial.

Social consequences of rapid environmental change.

While direct influences of the environment on population growth and resilience are well studied, indirect routes linking environmental changes to population consequences are less explored. We suggest that social behavior is key for understanding how anthropogenic environmental changes affect the resilience of animal populations. Social structures of animal groups are evolved and emergent phenotypes that often have demographic consequences for group members. Importantly, environmental drivers may directly influence the consequences of social structure or indirectly influence them through modifications to social interactions, group composition, or group size. We have developed a framework to study these demographic consequences. Estimating the strength of direct and indirect pathways will give us tools to understand, and potentially manage, the effect of human-induced rapid environmental changes.

Are genetic variation and demographic performance linked?

Quantifying relationships between genetic variation and population viability is important from both basic biological and applied conservation perspectives, yet few populations have been monitored with both long-term demographic and population genetics approaches. To empirically test whether and how genetic variation and population dynamics are related, we present one such paired approach. First, we use eight years of historical demographic data from five populations of Boechera fecunda (Brassicaceae), a rare, self-compatible perennial plant endemic to Montana, USA, and use integral projection models to estimate the stochastic population growth rate (λ S) and extinction risk of each population. We then combine these demographic estimates with previously published metrics of genetic variation in the same populations to test whether genetic diversity within populations is linked to demographic performance. Our results show that in this predominantly inbred species, standing genetic variation and demography are weakly positively correlated. However, the inbreeding coefficient was not strongly correlated with demographic performance, suggesting that more inbred populations are not necessarily less viable or at higher extinction risk than less inbred populations. A contemporary re-census of these populations revealed that neither genetic nor demographic parameters were consistently strong predictors of current population density, although populations showing lower probabilities of extinction in demographic models had larger population sizes at present. In the absence of evidence for inbreeding depression decreasing population viability in this species, we recommend conservation of distinct, potentially locally adapted populations of B. fecunda rather than alternatives such as translocations or reintroductions.

Population genomic monitoring provides insight into conservation status but no correlation with demographic estimates of extinction risk in a threatened trout.

The current extinction crisis requires effective assessment and monitoring tools. Genetic approaches are appealing given the relative ease of field sampling required to estimate genetic diversity characteristics assumed related to population size, evolutionary potential, and extinction risk, and to evaluate hybridization with non-native species simultaneously. However, linkages between population genetic metrics of diversity from survey-style field collections and demographic estimates of population size and extinction risk are still in need of empirical examples, especially for remotely distributed species of conservation concern where the approach might be most beneficial. We capitalized on an exceptional opportunity to evaluate congruence between genetic diversity metrics and demographic-based estimates of abundance and extinction risk from a comprehensive Multiple Population Viability Analysis (MPVA) in a threatened fish, the Lahontan cutthroat trout (LCT). We sequenced non-native trout reference samples and recently collected and archived tissue samples of most remaining populations of LCT (N = 60) and estimated common genetic assessment metrics, predicting minimal hybridization with non-native trout, low diversity, and declining diversity over time. We further hypothesized genetic metrics would correlate positively with MPVA-estimated abundance and negatively with extinction probability. We uncovered several instances of hybridization that pointed to immediate management needs. After removing hybridized individuals, cautious interpretation of low effective population sizes (2-63) suggested reduced evolutionary potential for many LCT populations. Other genetic metrics did not decline over time nor correlate with MPVA-based estimates of harmonic mean abundance or 30-year extinction probability. Our results demonstrate benefits of genetic monitoring for efficiently detecting hybridization and, though genetic results were disconnected from demographic assessment of conservation status, they suggest reduced evolutionary potential and likely a higher conservation risk than currently recognized for this threatened fish. We emphasize that genetic information provides essential complementary insight, in addition to demographic information, for evaluating species status.

Quantifying the conservation status and abundance trends of wildlife communities with detection-nondetection data.

Effective conservation requires understanding species' abundance patterns and demographic rates across space and time. Ideally, such knowledge should be available for whole communities because variation in species' dynamics can elucidate factors leading to biodiversity losses. However, collecting data to simultaneously estimate abundance and demographic rates of communities of species is often prohibitively time intensive and expensive. We developed a multispecies dynamic N-occupancy model to estimate unbiased, community-wide relative abundance and demographic rates. In this model, detection-nondetection data (e.g., repeated presence-absence surveys) are used to estimate species- and community-level parameters and the effects of environmental factors. To validate our model, we conducted a simulation study to determine how and when such an approach can be valuable and found that our multispecies model outperformed comparable single-species models in estimating abundance and demographic rates in many cases. Using data from a network of camera traps across tropical equatorial Africa, we then used our model to evaluate the statuses and trends of a forest-dwelling antelope community. We estimated relative abundance, rates of recruitment (i.e., reproduction and immigration), and apparent survival probabilities for each species' local population. The antelope community was fairly stable (although 17% of populations [species-park combinations] declined over the study period). Variation in apparent survival was linked more closely to differences among national parks than to individual species' life histories. The multispecies dynamic N-occupancy model requires only detection-nondetection data to evaluate the population dynamics of multiple sympatric species and can thus be a valuable tool for examining the reasons behind recent biodiversity loss.

La conservación efectiva requiere del entendimiento de los patrones de abundancia de las especies a lo largo del tiempo y el espacio. Sería ideal que dicho conocimiento estuviera disponible para todas las comunidades ya que la variación en la dinámica de las especies puede esclarecer los factores que llevan a la pérdida de la biodiversidad. Sin embargo, la recolección de información para estimar simultáneamente las tasas demográficas y de abundancia de las comunidades de especies con frecuencia es cara y consume tiempo. Desarrollamos un modelo multiespecies dinámico de ocupación-N para estimar la tasa demográfica y de abundancia relativas sin sesgos y en toda la comunidad. En este modelo usamos información de detección-no detección (p. ej.: censos repetidos de presencia-ausencia) para estimar los parámetros a nivel comunitario y de especie y los efectos de los factores ambientales. Para validar nuestro modelo, realizamos un estudio de simulación para determinar cómo y cuándo dicha estrategia puede ser valiosa y descubrimos que nuestro modelo multiespecies superó a los modelos comparables de una sola especie en la estimación de las tasas demográficas y de abundancia en muchos casos. Usamos nuestro modelo con datos de una red de cámaras trampa ubicadas a lo largo de África ecuatorial para evaluar los estados y tendencias de una comunidad forestal de antílopes. Estimamos la abundancia relativa, tasa de reclutamiento (es decir, reproducción e inmigración) y las probabilidades de supervivencia aparente para la población local de cada especie. La comunidad de antílopes fue bastante estable (aunque el 17% de las poblaciones [combinaciones especie-parque] declinaron durante el periodo de estudio). La variación en la supervivencia aparente estuvo vinculada con mayor cercanía a las diferencias entre los parques nacionales que a la historia de vida de cada especie individual. El modelo multiespecies dinámico de ocupación-N requiere solamente información de detección-no detección para evaluar las dinámicas poblacionales de muchas especies simpátricas y por lo tanto puede ser una herramienta valiosa para examinar las razones detrás de la pérdida reciente de la biodiversidad.