Population Viability Research Articles

Influence of Dolphin-Watching Tourism Vessels on the Whistle Emission Pattern of Common Dolphins and Bottlenose Dolphins

Recent years have seen a notable rise in dolphin-watching boat activities along the Algarve coast in Portugal, potentially affecting the common dolphin (Delphinus delphis) and bottlenose dolphin (Tursiops truncatus) local populations. This study examines the impact of increasing underwater noise levels from these boats on dolphin vocalizations. Field recordings were conducted from June to September 2022, analyzing dolphin whistles in various boat presence scenarios. The results indicate significant changes in whistle-frequency characteristics with boat presence, including increased start, low, and high frequencies, alongside a decrease in the number of inflection points in modulated whistles. The changes might negatively impact dolphin populations viability, underscoring the need for further research. Additionally, improved mitigation strategies may be necessary to reduce the potential negative effects of dolphin watching on cetacean communication and behavior in the Algarve region.

To breed or not to breed: Territory occupancy is predicted by reproductive performance and habitat heterogeneity.

Species life history and anthropogenic influence are important drivers of population performance and viability in human-dominated ecosystems. How these factors affect habitat selection and occupancy in long-lived species is an important topic for their conservation. Long-term datasets are needed for establishing the underlying drivers of this process. In this 22 year-long study, we conducted annual surveys of Bonelli's eagle in the east of the Iberian Peninsula. During this period, 42.8% of the known territories remained unoccupied. Territories with a higher likelihood of raising two chicks over time were stable, evidenced by a lower coefficient of variation in productivity, and were more likely to remain occupied. Moreover, territories with lower habitat diversity, dominated by coniferous forest or agricultural fields, and those located further away from the coast and at higher altitudes showed lower rates of occupancy (i.e., unoccupied >3 consecutive years). To validate these associations, we monitored space use of 22 individuals equipped with Global Positioning System/Global System for Mobile (GPS/GSM) transmitters, which confirmed that eagles selected for open habitats (mainly scrublands and transitional woodland-scrubs) intermixed with forest areas within their home ranges. In contrast, individuals avoided areas dominated by agricultural, urban, and continuous forests for breeding in line with the observations for unoccupied territories. Our results highlight the important interplay between natural and anthropogenic factors, which also have important implications for other raptor species. Preservation of the most productive territories and the re-occupancy of unoccupied territories along with reducing threats in the preferred habitats are fundamental actions that should be taken immediately to sustain viable populations. Potential management actions include enhancing natural prey density through habitat restoration and conservation, mitigating threats and reducing mortality risks due to power lines, fences, poisoning, and maintaining habitat heterogeneity important to eagles' hunting activities.

Teleconnection between the Reproductive Parameters of the Bearded Vulture and Macroclimatic Oscillations: Implications for Conservation

ABSTRACT The Bearded Vulture (Gypaetus barbatus) is a scavenging bird of prey that was once widespread on the Iberian Peninsula. Its current distribution in Spain is limited to specific mountain ranges, including the Aragonese Pyrenees. The decline of the Iberian population has been linked to factors acting at a microscale level, such as the use of poisons, illegal hunting, and a decrease in extensive livestock farming. There are, however, other factors acting on a biogeographical scale that are not currently being considered and may also be affecting the viability of populations. The aim of this case study was to investigate the influences of large-scale environmental conditions on temporal variation in the reproductive parameters of the Bearded Vulture breeding population in the Aragonese Pyrenees. We tested the degree to which each of 26 macroclimatic oscillation indices with an effect on regional weather conditions were teleconnected with three reproductive parameters (hatching rate, fledging rate, and productivity). Two indices—the Tropical Northern Atlantic and East Atlantic/West Russia Pattern—were temporally correlated with Bearded Vulture reproductive parameters. The study results provide novel information to facilitate Bearded Vulture conservation because no previous studies have addressed this issue from a biogeographical and macroecological perspective. The results could have important implications for the management and conservation of the species and its successful reintroduction in other territories.

Common hamster (Cricetus cricetus, Cricetidae, Rodentia) in the Simferopol city: Population dynamics and survival outlook

In the Simferopol city, the numbers of Common hamsters began to grow since the early 1970s and reached a peak in the mid-1990s. The abundance was kept at a high level until 2014–2015 and then began to decline. In multi-storey residential development areas, steady settlements of hamsters have now virtually disappeared, and even in large green areas (the City Park and Botanical Garden), the numbers dropped almost tenfold. One of the possible causes for this decline was cutting down shrubs and hedges, which began since 2016–2017. However, the population has also severe declined in areas with no such activities. Thus, the fate of the Simferopol hamster population is worrisome. Obviously, we are dealing with a multi-factor process which requires special studying, without which no estimating of population viability or developing of conservation measures are possible.

Human sensory-like neuron cultivation-An optimized protocol.

Reprogramming of human-induced pluripotent stem cells (iPSCs) and their differentiation into specific cell types, such as induced sensory-like neurons (iSNs), are critical for disease modeling and drug testing. However, the variability of cell populations challenges reliability and reproducibility. While various protocols for iSN differentiation exist, the development of non-iSN cells in these cultures remains an issue. Therefore, standardization of protocols is essential. This study aimed to improve iSN culture conditions by reducing the number of non-iSN cells while preserving the survival and quality of iSNs. iSNs were differentiated from a healthy control iPSC line using an established protocol. Interventions for protocol optimization included floxuridine (FdU) or 1-β-D-arabinofuranosyl-cytosine hydrochloride (AraC) treatment, magnetic-activated cell sorting (MACS), early cell passaging, and replating. Cell viability and iSN-to-total-cell-count ratio were assessed using a luminescent assay and immunocytochemistry, respectively. Passaging of cells during differentiation did not increase the iSN-to-total-cell-count ratio, and MACS of immature iSNs led to neuronal blebbing and reduced the iSN-to-total-cell-count ratio. Treatment with high concentrations and prolonged incubation of FdU or AraC resulted in excessive cell death. However, treatment with 10 μM FdU for 24 h post-differentiation showed the most selective targeting of non-iSN cells, leading to an increase in the iSN-to-total-cell count ratio without compromising the viability or functionality of the iSN population. Replating of iSNs shortly after seeding also helped to reduce non-iSN cells. In direct comparison with other methods, treatment with 10 μM FdU for 24 h after differentiation shows promise for improving iSN culture purity, which could benefit downstream applications in disease modeling and drug discovery. However, further investigations involving multiple iPSC lines and optimization of protocol parameters are warranted to fully exploit the potential of this method and enhance its reproducibility and applicability. Overall, this study provides valuable insights into optimizing culture conditions for iSN differentiation and highlights the importance of standardized protocols in iPSC-based research.

Evaluating the effects of nest management on a recovering raptor using integrated population modeling

AbstractEvaluating population responses to management is a crucial component of successful conservation programs. Models predicting population growth under different management scenarios can provide key insights into the efficacy of specific management actions both in reversing population decline and in maintaining recovered populations. Bald eagle (Haliaeetus leucocephalus) conservation in the United States has seen many successes over the last 50 years, yet the extent to which the bald eagle population has recovered in Arizona, an important population within the Southwest region, remains an area of debate. Estimates of the species' population trend and an evaluation of ongoing nest‐level management practices are needed to inform management decisions. We developed a Bayesian integrated population model (IPM) and population viability analysis (PVA) using a 36‐year dataset to assess Arizona bald eagle population dynamics and their underlying demographic rates under current and possible future management practices. We estimated that the population grew from 77 females in 1993 to 180 females in 2022, an average yearly increase of 3%. Breeding sites that had trained personnel (i.e., nestwatchers) stationed at active nests to mitigate human disturbance had a 28% higher reproductive output than nests without this protection. Uncertainty around population trends was high, but scenarios that continued the nestwatcher program were less likely to predict abundance declines than scenarios without nestwatchers. Here, the IPM‐PVA framework provides a useful tool both for estimating the effectiveness of past management actions and for exploring the management needs of a delisted population, highlighting that continued management action may be necessary to maintain population viability even after meeting certain recovery criteria.

Harvest sustainability assessments need rethinking under climate change: A ringed seal case study from Svalbard, Norway

AbstractThroughout the Arctic, ice‐affiliated marine mammals constitute local subsistence resources but detrimental effects of declines in their sea ice habitats create a need for harvest sustainability assessments in light of climate change. At the same time, empirical data required for thorough population analysis of these species are often sparse at best, as illustrated by the focal species in this study, ringed seals in Svalbard: the last population survey took place two decades ago (2002–2003), demographic data are limited to age, sex, and reproductive status of a small subset of shot individuals, and harvest reporting is patchy and incomplete. Data sparsity is one of the main reasons why potential biological removal (PBR) became a commonly used tool for assessing sustainability of marine mammal harvests. Herein, we calculated PBR for Svalbard ringed seals using both recommended default parameters and population‐specific parameters obtained from an integrated population model (IPM). PBR estimates were highly uncertain, suggesting the number of sustainably harvestable individuals could lie anywhere between 0 and 91, with a substantial chance of any harvest being unsustainable under current environmental conditions and trends. Subsequent population viability analyses (PVAs) further confirmed that the current harvest was likely unsustainable, even in a scenario in which sea ice conditions would not deteriorate (and therefore lower pup survival) further. However, uncertainty in population projections was high, and forecasts thus not ideal for formulating management advice. Better forecasts will require more frequent population surveys and obtaining more knowledge regarding the links between vital rates and environmental conditions, both of which may be facilitated by the adoption of novel technology (e.g., drone monitoring, genetic studies). The modeling framework created in this study can be readily updated with new data as they become available, and can serve as a tool for adaptive management of this and other marine mammal populations.

Non-senescent species are not immortal: Stress and decline in two planaria species.

Potential immortality is observed in several species (e.g. prickly pear cactus, hydra and flatworms) and is indicative of their negligible or even negative senescence rates. Unlike in senescent species, which experience reduced individual performance with age due to physiological degradation, species with negligible or negative senescence display mortality rates that remain constant or decline with age, respectively. These rates vary across taxa and are correlated with life history traits. Yet, the extent to which variable resource availability, a key driver of variation in life history traits, impacts species that show negligible or negative senescence is currently unknown. Here, we examine whether and how variation in the quantity, quality and feeding interval of resources impact population structure, population performance and life history trait trade-offs in two long-lived planaria that do not senesce: Schmidtea mediterranea and Dugesia tahitiensis. In a full factorial design, different combinations of resource quantity (reduced intake, standard intake and high intake) and quality (high and low quality) were provided in two different feeding intervals (7-day and 14-day intervals) for 19 weeks. We show that variability in resource availability, via decreases in quantity, quality and frequency of resources, does not diminish population viability in either species but does result in suboptimal conditions of stress in S. mediterranea. The high population viability we report can be attributed to two different mechanisms: increased reproduction or increased investment into maintenance at the expense of reproduction. Moreover, which mechanism was responsible for said high population viability was context-dependent and modulated by the specific life history strategy of the two planaria species. We show that suboptimal conditions can cause stress responses that have significant impacts on non-senescent species. The context-dependent response we observe suggests that species that do not senesce but are subject to suboptimal conditions of stress may ultimately exhibit declines in performance and ultimately die. A clearer understanding of the impact of suboptimal conditions of resource availability on non-senescent species is needed to determine the extent of stress experienced and ultimately whether a species can truly be immortal.

Recurrent marine heatwaves compromise the reproduction success and long-term viability of shallow populations of the Mediterranean gorgonian Eunicella singularis

Mediterranean gorgonians are being threatened by the impact of recurrent extreme climatic events, such as marine heatwaves (MHWs). The white gorgonian Eunicella singularis was suggested to be the most resistant gorgonian species in the NW Mediterranean, mainly due to the presence of symbiotic algae. However, a substantial shift in the conservation condition of the species has been observed in the recent years. The aim of this study is to evaluate the lethal and sublethal effects of recent MHWs on the populations of E. singularis. Our results show that recurrent MHWs have impacted both the demography and reproduction of the species between 2002 and 2020, driving mortalities up to 36%, an increase in the percentages of non-reproducing adult colonies (11-58%), and a significant decrease in the recruitment rates. Although E. singularis is a highly dynamic species in comparison with other temperate gorgonians, the present study suggests that the persistence of this species may be severely compromised under recurrent MHWs, at least at shallowest depths.

Enumeration and gentle sorting of immune cells on chip, key to next generation advanced therapies in outpatient setting

BackgroundA thorough understanding of immune-oncology and molecular medicine has been vital in the development of cell therapeutics. At the basis of this translational research and its future implementation into a medicinal product, lies the availability of pure and viable cell populations. Currently, FACS and magnetic bead isolation are successfully used but suffer to fulfill all requirements. FACS is costly and difficult to upscale due to the limitation of shear stress, especially fragile, cells can handle. Therefore, magnetic bead isolation is often used as it is gentler, but it lacks the multiparametric aspect to isolate more complex cellular profiles. AimsWe aim to develop a versatile technology able of multi marker detection and isolation of complex cell types with high purity, viability and throughput. MethodsWe have developed a gentle sorting mechanism based on a jet flow created by micro vapor bubbles, enabling a closed microfluidic cell isolation platform capable of multiparametric sorting with high viability, purity and throughput. In this work we compared the purity, recovery and viability of sorted CD4+ CD14- cells to magnetic isolation, most often used for other cell manufacturing approaches. Futhermore, we cultured the sorted cells of both isolation strategies and compared their growth curve and expression of activation-induced IL2 and IFN-γ. ResultsWe demonstrate that this tool can achieve a pure population of CD4+ CD14- cells with high viability after sorting without compromising the recovery. On top of the viability also the growth and activation potential of sorted cells is unhampered by comparison to the benchmark gentle magnetic isolation. ConclusionsOur technology allows for the development of a compact system which sets it apart from other efforts intended to create automated cell therapeutic solutions.

Unraveling the Complexity of the N e/N c Ratio for Conservation of Large and Widespread Pelagic Fish Species: Current Status and Challenges.

Estimating and understanding the ratio between effective population size (N e) and census population size (N c) are pivotal in the conservation of large marine pelagic fish species, including bony fish such as tunas and cartilaginous fish such as sharks, given the challenges associated with obtaining accurate estimates of their abundance. The difficulties inherent in capturing and monitoring these species in vast and dynamic marine environments often make direct estimation of their population size challenging. By focusing on N e, it is conceivable in certain cases to approximate census size once the N e/N c ratio is known, although this ratio can vary and does not always increase linearly, as it is influenced by various ecological and evolutionary factors. Thus, this ratio presents challenges and complexities in the context of pelagic species conservation. To delve deeper into these challenges, firstly, we recall the diverse types of effective population sizes, including contemporary and historical sizes, and their implications in conservation biology. Secondly, we outline current knowledge about the influence of life history traits on the N e/N c ratio in the light of examples drawn from large and abundant pelagic fish species. Despite efforts to document an increasing number of marine species using recent technologies and statistical methods, establishing general rules to predict N e/N c remains elusive, necessitating further research and investment. Finally, we recall statistical challenges in relating N e and N c emphasizing the necessity of aligning temporal and spatial scales. This last part discusses the roles of generation and reproductive cycle effective population sizes to predict genetic erosion and guiding management strategies. Collectively, these sections underscore the multifaceted nature of effective population size estimation, crucial for preserving genetic diversity and ensuring the long-term viability of populations. By navigating statistical and theoretical complexities, and addressing methodological challenges, scientists should be able to advance our understanding of the N e/N c ratio.

Reference-based genome assembly and comparative genomics of Calamus Brandisii Becc. for unveiling sex-specific genes for early gender detection.

Calamus brandisii Becc. is an endangered rattan species indigenous to the Western Ghats of India and used in the furniture and handicraft industries. However, its dioecious nature and longer flowering time pose challenges for conservation efforts. Developing markers for early gender detection in seedlings is crucial for maintaining viable populations for in-situ and ex-situ conservation. Currently, no sex chromosomes or gender-specific genes have been reported in the species. We report the first comprehensive comparative genomics study between the male and female genomes of C. brandisii to identify polymorphisms and potential genes for gender determination. Reference-based assembly was conducted and the male and female genomes were predicted to contain 43,810 and 50,493 protein-coding genes respectively. The haploid genome size was ∼691Mb and ∼884Mb for male and female genomes respectively. Comparative analysis revealed significant genetic variation between the two genomes including 619,776 SNPs, 73,659 InDels, 212,123 Structural variants (SVs) and 305 copy number variations (CNVs). A total of 5 male-specific and 11 female-specific genes linked to the sex determining region was predicted. The genomic variants identified between the two genomes could be used in development of markers for early gender identification in C. brandisii for restoration programs. The gender-specific genes identified in this study also provide new insights into the mechanisms of sex determination and differentiation in rattans.

Different Combinations of Nitrogen and Carbon Sources Influence the Growth and Postbiotic Metabolite Characteristics of Lactiplantibacillus plantarum Strains Isolated from Malaysian Foods.

Postbiotic metabolites produced by Lactiplantibacillus plantarum strains isolated from Malaysian food have been extensively reported for their positive effects on health. Understanding the effects of different combinations of carbon and nitrogen sources on the growth and corresponding characteristics of postbiotic metabolites produced by different strains of L. plantarum is important for various applications. Hence, the effects of different combinations of carbon (glucose, lactose, sucrose and dextrose) and nitrogen (X-SEED Kat, X-SEED Peptone, X-SEED Nucleo Advanced, Nucel875 MG, FM888 and FM902) sources on the growth of six strains of L. plantarum (RG11, RG14, RI11, RS5, TL1 and UL4) and the functional characteristics (bacteriocin inhibitory activity, antioxidant activity and lactic acid concentration) of their respective postbiotic metabolites were investigated in this study. UL4 produced the highest viable cell population with sucrose and Nucel875 nitrogen source. The UL4 strain also produced the strongest bacteriocin inhibitory activity with dextrose and FM888 nitrogen source. In comparison, the RI11 strain produced the highest lactic acid concentration with dextrose and Nucel875 nitrogen source and the highest reducing power of RS5 and TL1 postbiotic metabolites was achieved with MRS medium. In the combination of sucrose and X-Seed KAT nitrogen source, RG14 produce the highest hydroxyl radical scavenging activity. The effects of different combinations of carbon and nitrogen sources on the viable cell population of L. plantarum strains and the respective functional characteristics of postbiotic metabolites were strain dependent. The current study also revealed that fermentation media were an important factor that greatly impacted the functionalities of postbiotic metabolites due to the presence of various bioactive compounds that contributed to high antioxidant and antimicrobial properties. The results of this study will facilitate the subsequent medium design and optimisation for the development and production of specific postbiotic metabolites produced by the respective L. plantarum strain for their applications in various industries.

Climatic variation and risk assessment in a highly seasonal mammal

Abstract Climate change and its resulting effects on seasonality are known to alter a variety of animal behaviors including those related to foraging, phenology, and migration. While many studies focus on the impacts of phenological changes on physiology or fitness enhancing behaviors, fewer have investigated the relationship between variation in weather and phenology on risk assessment. Fleeing from predators is an economic decision that incurs costs and benefits. As environmental conditions change, animals may face additional stressors that affect their decision to flee and influence their ability to effectively assess risk. Flight initiation distance (FID)–the distance at which animals move away from threats–is often used to study risk assessment. FID varies due to both internal and external biotic and physical factors as well as anthropogenic activities. We asked whether variation in weather and phenology is associated with risk-taking in a population of yellow-bellied marmots (Marmota flaviventer). As the air temperature increased marmots tolerated closer approaches, suggesting that they either perceived less risk or that their response to a threat was thermally compromised. The effect of temperature was relatively small and was largely dependent upon having a larger range in the full data set that permitted us to detect it. We found no effects of either the date that snow disappeared or July precipitation on marmot FID. As global temperatures continue to rise, rainfall varies more and drought becomes more common, understanding climate-related changes in how animals assess risk should be used to inform population viability models.

Fecundity without nectar is insufficient for the persistence of a blue butterfly.

Organisms with complex life cycles undergo ecological transitions between life stages, often resulting in stage-specific resource use. The relative contribution of each stage-specific resource to vital rates influences population dynamics and subsequently whether habitats can support viable populations. In lepidopterans, survival to reproduction requires sufficient resources for immature life stages, but the extent to which resources for adults are critical to population persistence is variable. We studied Boisduval's blue butterflies (Icaricia icarioides), in a greenhouse experiment, to quantify the effect of the adult diet, nectar, on vital rates. Butterflies fed ad libitum produced 3.4 times more eggs, on average, over their lifetime and lived 6 more days relative to those which only had access to water. We used these experimental data to parameterize a population model to test if vital rates with and without nectar result in viable population growth rates. Despite individual females laying 68 eggs without nectar, we found that Boisduval's blue butterfly populations will not persist without the improved fecundity associated with nectar resources (λ<1). In this species, although amino acids in the adult diet contributed to various improvements in fecundity, these improvements did not translate to improvements in population growth rates. Incorporating our experimental vital rates into a population model indicates that the relative abundance and quality of nectar can alter at what threshold other resource(s) are limiting the population.

The molecular impact of sonoporation: A transcriptomic analysis of gene regulation profile

Sonoporation has long been known to disrupt intracellular signaling, yet the involved molecules and pathways have not been identified with clarity. In this study, we employed whole transcriptome shotgun sequencing (RNA-seq) to profile sonoporation-induced gene responses after membrane resealing has taken place. Sonoporation was achieved by microbubble-mediated ultrasound (MB-US) exposure in the form of 1 MHz ultrasound pulsing (0.50 MPa peak negative pressure, 10 % duty cycle, 30 s exposure period) in the presence of microbubbles (1:1 cell-to-bubble ratio). Using propidium iodide (PI) and calcein respectively as cell viability and cytoplasmic uptake labels, post-exposure flow cytometry was performed to identify three viable cell populations: 1) unsonoporated cells, 2) sonoporated cells with low uptake, and 3) sonoporated cells with high uptake. Fluorescence-activated cell sorting was then conducted to separate the different groups followed by RNA-seq analysis of the gene expressions in each group of cells. We found that sonoporated cells with low or high calcein uptake showed high similarity in the gene responses, including the activation of multiple heat shock protein (HSP) genes and immediate early response genes mediating apoptosis and transcriptional regulation. In contrast, unsonoporated cells exhibited a more extensive gene expression alteration that included the activation of more HSP genes and the upregulation of diverse apoptotic mediators. Four oxidative stress-related and three immune-related genes were also differentially expressed in unsonoporated cells. Our results provided new information for understanding the intracellular mobilization in response to sonoporation at the molecular level, including the identification of new molecules in the sonoporation-induced apoptosis regulatory network. Our data also shed light on the innovative therapeutic strategy which could potentially leverage the responses of viable unsonoporated cells as a synergistic effector in the microenvironment to favor tumor treatment.

Genomic and fitness consequences of a near-extinction event in the northern elephant seal.

Understanding the genetic and fitness consequences of anthropogenic bottlenecks is crucial for biodiversity conservation. However, studies of bottlenecked populations combining genomic approaches with fitness data are rare. Theory predicts that severe bottlenecks deplete genetic diversity, exacerbate inbreeding depression and decrease population viability. However, actual outcomes are complex and depend on how a species' unique demography affects its genetic load. We used population genetic and veterinary pathology data, demographic modelling, whole-genome resequencing and forward genetic simulations to investigate the genomic and fitness consequences of a near-extinction event in the northern elephant seal. We found no evidence of inbreeding depression within the contemporary population for key fitness components, including body mass, blubber thickness and susceptibility to parasites and disease. However, we detected a genomic signature of a recent extreme bottleneck (effective population size = 6; 95% confidence interval = 5.0-7.5) that will have purged much of the genetic load, potentially leading to the lack of observed inbreeding depression in our study. Our results further suggest that deleterious genetic variation strongly impacted the post-bottleneck population dynamics of the northern elephant seal. Our study provides comprehensive empirical insights into the intricate dynamics underlying species-specific responses to anthropogenic bottlenecks.

Population viability analysis for the common mudpuppy: Assessing potential impacts of TFM lampricide bycatch

AbstractBycatch is one of the leading threats facing aquatic organisms, worldwide. Pesticide bycatch can occur when nontarget species are incidentally killed during chemical application targeting noxious species. The common mudpuppy (Necturus maculosus) is a river‐dwelling salamander that is susceptible to bycatch from 3‐trifluoromethyl‐4‐nitrophenol (TFM) applications. However, the long‐term consequences of TFM bycatch on mudpuppy populations are not well understood. We used population viability analysis to reveal potential impacts of TFM application on a mudpuppy population in Ohio's Grand River under plausible bycatch scenarios. We found that the population was more sensitive to increased juvenile mortality and rapid declines occurred when both adults and juveniles were impacted at high bycatch rates (≥5% of the population) or more frequent TFM intervals (≥5 years). Our results suggest that continued use of TFM could pose a risk to mudpuppy population persistence if bycatch occurs at moderate to high levels and affects both juveniles and adults. Future TFM use and management decisions should be directed with these potential nontarget impacts in mind.

Making Noah's Ark Work for Fishing Cat Conservation: A Blueprint for Connecting Populations across an Interactive Wild Ex Situ Spectrum.

The One Plan Approach advocates for a hybrid species management framework, wherein captive-bred populations are considered metapopulations nested within a broader network of zoos and wild populations Additionally, the Opportunities to Thrive framework aims to enhance animal welfare by addressing the physiological, psychological, and emotional needs of captive individuals, thereby improving conservation outcomes. Here, we present an integrated framework for the conservation of a globally threatened wetland wild cat species, the fishing cat, by synthesizing optimal ex situ management practices and in situ conservation strategies. Further, we examined the genetic constitution of the founder population in a fishing cat captive breeding program that was recently initiated by the West Bengal Zoo Authority, India and conducted a population viability analysis to suggest how best to maintain the genetic diversity of the population. We found that the present genetic diversity of 56% and maximum carrying capacity of the captive population (30 individuals) can be maintained for more than 100 years with a combination of supplementation and harvesting. Keeping stochastic events in mind, the introduction of two adult males and females to the existing population each year will seamlessly allow the harvesting of two adult males and two adult females every alternate year to supplement wild populations. Further, we adopted the proposed integrated framework to delineate recommendations for the supplementation of wild populations in West Bengal. We used environmental criteria known to influence fishing cat occurrence to identify 21 potential reintroduction zones in the Sundarbans landscape and Terai region in northern West Bengal with habitable areas for the fishing cat that are larger than the maximum known species' home range. Our study is timely and insightful because it provides a holistic blueprint for implementing the One Plan Approach in safeguarding a threatened species.

Resource-based modelling approach to studying evolutionary rescue.

In this paper, we present an in-depth investigation into the dynamics of evolutionary rescue using a resource-based modelling approach. Utilizing classical consumer-resource models, we aim to understand how species can adapt to abrupt environmental changes that alter the availability of substitutable resources. Through both analytical solutions and simulation-based techniques, we explore the conditions under which populations can recover from critical sizes and avoid extinction. Our findings highlight the importance of minimum viable population sizes, mutation rates, and the adaptive capacity of metabolic strategies in influencing population resilience. We demonstrate that while increased mutation rates can facilitate faster recovery by enabling populations to evolve new metabolic strategies suited to the altered resource landscape, populations starting with smaller sizes or facing severe reductions in resource availability are more susceptible to extinction. This study offers valuable insights into the interplay between ecological dynamics and evolutionary mechanisms, providing a comprehensive framework for predicting population persistence and informing conservation strategies under changing environmental conditions.