Search Results (116)

Clupeiform bait fishes play critical roles in marine food chains and fisheries worldwide. Despite a paradigm of large stocks in temperate regions, the structure of clupeiform populations in complex coral reef environments is poorly described. This study assessed the population structure of a small reef-based clupeiform, Spratelloides delicatulus, over spatial scales of kilometres to 1000’s of kilometres on the Great Barrier Reef using sequence data from the control region of the mitochondrial D-Loop. Following confirmation of the species, we found strong stock structure within the metapopulation of the GBR. Three significantly different stock units were found, and these were closely related to three strongly divergent clades that were associated with changes in latitude. Within these stocks, a surprisingly strong structure was observed among reefs separated at scales of less than 10 km. This species likely has a complex demographic history with recent expansion and potential for incipient cryptic speciation evident by the sympatry observed at some reefs. The short lives and complex stock structure we have found for sprats on coral reefs contrasts with the findings from traditional stocks of high latitude clupeiforms. Full article

Lack of recombination in parthenogenetic organisms limits their ability to adapt to changing environments by natural selection. However, some obligatory parthenogens, such as rock lizards of the genus Darevskia, could survive for millions of years across multiple Pleistocene glaciations. There are different explanations for this phenomenon. Analysis of phenotypic variation may shed further light on the high adaptability of the parthenogenetic lizards. We compared the genetic and phenotypic variability of 186 individuals of the parthenogenetic Darevskia dahli and 54 individuals of its sexually reproducing paternal species, D. portschinskii, whose ranges almost coincide in Georgia (the Caucasus). The analysis showed that, despite the higher genetic variability of the individuals and metapopulations of D. portschinskii, phenotypic variability (as measured by KW dispersion and the normalized effective number of individuals per metapopulation), based on the nominal traits, was almost equal in the two species. Moreover, phenotypes of the parthenogen correlated with the distances among the localities, and with the annual rainfall level at a locality. The latter species also had more outlier phenotypes. Phenotypic plasticity may be a strategy for adaptation of parthenogenetic rock lizards, to a certain extent, compensating for the lack of genetic diversity. Full article

During public health emergencies, individuals typically obtain epidemic-related information through mass media channels and personal social media platforms. This information enables them to monitor epidemic progression and adjust their preventive behaviors accordingly to mitigate infection risks. To capture these processes, this paper proposes a three-layer coupled metapopulation network model that investigates the effects of regional mass media and social information propagation on the spatial spread of epidemic. The mass media layer represents regional outlets that propagate epidemic-related information to individuals within corresponding patches. Migrant individuals not only follow mass media information of the residential patch, but also continue to follow mass media information from their destination patch. The information layer captures the dynamics of information exchange on social media platforms. The epidemic layer depicts the spread of the epidemic within the metapopulation network and simulates the reaction-diffusion dynamics of migrating individuals across different patches through a Migration-Interaction-Return (MIR) mechanism; the coupling between the information layer and the epidemic layer is asymmetric. Theoretical analysis using the Microscopic Markov Chain Approach (MMCA) derives the evolution equation and determines the epidemic thresholds, while Monte Carlo (MC) simulations validate the model and explore factors influencing propagation dynamics. Our research indicates that when migrants simultaneously receive mass media information from both residential and destination patches, it significantly enhances information coverage and promotes protective behaviors, thereby effectively suppressing epidemic spread. Furthermore, promoting information propagation—particularly the communication among individuals within a patch—significantly increases the proportion of aware individuals, reduces the infection scale, and raises the epidemic threshold. Notably, population migration would originally lead to an increase in infection scale, but as the intensity of information propagation strengthens, migration instead has a good effect on controlling epidemic spread. These results provide deeper insights into the role of awareness propagation and human mobility in epidemic containment. Full article

Threats to forest ecosystems from pest insects are supposed to become more severe due to climate change. Therefore, understanding the dynamics of forest pest insects and the mechanisms of their outbreaks is going to be of even greater importance. To understand these phenomena and cope with the consequences, the question of which patterns show meta-populations of pest insects before and after outbreaks is of high interest. Therefore, long-term studies have been carried out in two research areas in North-West Poland with the aim of studying the fluctuations of meta-populations of the Nun moth (Lymantria monacha L.) (Lepidoptera: Erebidae) using pheromone traps. Synchronization of the fluctuations at the individual study plots was tested for correlations with the numbers of the Nun moth per trap, changes in the numbers of the Nun moth per trap, and the growth factors. The studied Nun moth meta-populations showed a certain pattern in fluctuations of their sub-populations (interaction groups) with phases of asynchronous and synchronous fluctuations; the latter seem to be important when it comes to distinctive peaks in Nun moth numbers in the meta-populations. We conclude that predicting population dynamics of the Nun moth demands long-term studies, including research on both density-dependent factors and stochastic processes. Full article

In this study, we formulate and analyze a susceptible–infected–susceptible (SIS) dynamic on metapopulation networks, where each node has a finite carrying capacity and the motion of individuals is modulated by vacant space at the destination. We obtain that the vacancy-dependent mobility pattern results in various asymptotic population distributions on heterogeneous metapopulation networks. The resulting population distributions have remarkable impact on the behavior of SIS dynamics. We show that, for the given total number of individuals, higher heterogeneity in population distributions facilitates epidemic spreading in terms of both a smaller epidemic threshold and larger macroscopic incidence. Moreover, we analytically obtain a sufficient condition that the disease-free equilibrium becomes unstable and an endemic state arises. Contrary to the absence of an epidemic threshold in the standard diffusion case without excluded-volume effects, the finite carrying capacity induces a nonzero epidemic threshold under certain conditions in the limit of infinite network sizes with an unbounded maximum degree. Our analytical results agree well with numerical simulations. Full article

In 1982 a conservation project was initiated to restore glade communities in the Missouri Ozarks with a special emphasis on collared lizards (Crotophytus collaris), a state threatened species at the time. Starting in 1984, collared lizards were translocated onto restored glade habitats on Stegall Mountain in the Ozarks. The populations persisted but did not colonize other glades on Stegall until 1994, when prescribed fires included not only the glades, but also the surrounding woodland. Starting in 1999, landscape-level burns connected Stegall to three nearby mountains. The goal of this study was to test the hypothesis that expanding prescribed burns to the forested woodlands between Stegall Mountain and nearby mountains would create dispersal corridors for the colonization of glades on new mountains. Indeed, all three mountains were colonized and direct dispersal of marked lizards from Stegall was observed following the prescribed fires. Inter-mountain colonization dynamics and patterns varied: one was absorbed into the Stegall meta-population, another experienced a founder event followed by rapid colonization, and the third underwent repeated failed colonization attempts before successful establishment years later. These diverse patterns were consistent with differences in landscape resistance in the inter-mountain corridors rather than in geographical distance. Intra-mountain colonization patterns indicated that lizards assessed glade quality based on multiple factors. High landscape resistance resulted in a young age structure in the initial colonizing population. This young age structure interacted with the territorial behavior of collared lizards, age of reproduction, and probability of dispersal. This strong interaction between landscape resistance in the dispersal corridor and social behavior in the colonizing population is a novel factor in predicting colonization dynamics. Moreover, these results highlight the importance of social behavior on dispersal decisions versus habitat quality alone. Full article

Due to small population size, Population Viability Analysis (PVA) of endangered species often pools all individuals into a single matrix to decrease variation in estimation of transition rates. These pooled populations may mask significant environmental variation among populations, affecting estimates. Using 10 years of population data (2000–2010) on the endangered plant Jacquemontia reclinata in Southeastern Florida, USA, I parameterized a stage-structured matrix model and calculated annual growth rates (lambdas)and elasticity for each year using stochastic matrix models. The metapopulation model incorporating actual dynamics of the two largest populations showed a lower occupancy rate and higher risk of extinction at an earlier time compared to a model that used the average of all natural populations. Analyses were consistent that incorporating population variation versus average dynamics in modeling J. reclinata demography results in more variation and greater extinction risk. Local variation may be due to both weather (including minimum winter temperature and total annual precipitation) and local disturbance dynamics in these urban preserves. Full article

The tufted deer (Elaphodus cephalophus), a Near-Threatened (NT) species endemic to China and Myanmar, requires robust genetic data for effective conservation. However, the genetic landscape of key populations, such as those in Chongqing, remains poorly understood. This study aimed to comprehensively evaluate the genetic diversity, population structure, gene flow, and demographic history of tufted deer across this critical region. We analyzed mitochondrial DNA (mtDNA) from 46 non-invasively collected fecal samples from three distinct populations: Jinfo Mountain (JF, n = 13), Simian Mountain (SM, n = 21), and the Northeastern Mountainous region (NEM, n = 12). Genetic variation was assessed using the cytochrome b (Cyt b) and D-loop regions, with analyses including F_st, gene flow (N_m), neutrality tests, and Bayesian Skyline Plots (BSP). Our results revealed the highest genetic diversity in the SM population, establishing it as a genetic hub. In contrast, the JF population exhibited the lowest diversity and significant genetic differentiation (>0.23) from the SM and NEM populations, indicating profound isolation. Gene flow was substantial between SM and NEM but severely restricted for the JF population. Demographic analyses, including BSP, indicated a long history of demographic stability followed by a significant expansion beginning in the Middle to Late Pleistocene. We conclude that the SM/NEM metapopulation serves as the genetic core for the species in this region, while the highly isolated JF population constitutes a distinct and vulnerable Management Unit (MU). This historical demographic expansion is likely linked to climatic and environmental changes during the Pleistocene, rather than recent anthropogenic factors. These findings underscore the urgent need for a dual conservation strategy: targeted management for the isolated JF population and the establishment of ecological corridors to connect the Jinfo Mountain and Simian Mountain populations, ensuring the long-term persistence of this unique species. Full article

We investigated the dispersal ability of Euphydryas aurinia provincialis in a local-scale analysis within a single habitat patch of the Colfiorito highlands metapopulation. Our findings indicate that inside a single node, the organization of nesting patches can be conceptualized as a metapopulation itself, where reproductive sites, despite their spatial proximity, can act as either source or sink habitats depending on environmental conditions. We conducted fieldwork in six nesting patches inside a single node, capturing, marking, and recapturing individuals to assess their spatial distribution and movement tendencies at a large landscape scale. We found a high degree of site fidelity among individuals, with many recaptures occurring within the original marking site, but also a sex-based difference in movement patterns; females dispersed farther than males, likely driven by reproductive strategies, while males remained more localized, prioritizing mate-searching. Our findings suggest a complex dynamic in habitat connectivity: pastures and abandoned fields, despite being open, seem to act like sink areas, while breeding sites with shrub and tree cover act as source habitats, offering optimal conditions for reproduction. Individuals, especially females, from these source areas were later compelled to disperse into open habitats, highlighting a nuanced interaction between landscape structure and population dynamics. These results highlight the importance of maintaining habitat corridors to support metapopulation dynamics and prevent genetic isolation; the abandonment of traditional grazing practices is leading to the rapid closure of these source habitats, posing a severe risk of local extinction. Conservation efforts should prioritize the preservation of these source habitats to ensure the long-term viability of E. a. provincialis populations in fragmented landscapes. Full article

Assessing the ranging and dispersal behavior of apex predators and its consequences for landscape connectivity is of paramount importance for understanding population and ecosystem effects of anthropogenic land use change. Here, we synthesize ranging and dispersal ecological information on pumas (Puma concolor) and present estimates of how different land uses affect the space use and dispersal of pumas on fragmented landscapes in an ecotone between biodiversity hotspots in southeastern Brazil. Additionally, we evaluate the effect of animal translocations on dispersal and movement patterns. Using location data for 14 GPS-collared pumas and land use data, we assessed when, how long, and how far individuals dispersed; how forest loss and infrastructure influenced puma home range size; and how movement patterns changed according to land use and proximity to infrastructure, during ranging and dispersal, for residents, natural dispersers, and translocated individuals. We present the first detailed record on the dispersal of pumas in Brazil and in the tropics, including long-distance dispersals, and show that pumas moved faster and more linearly during dispersal than during ranging. Their movement was slower and their home ranges were smaller in more forested areas, underscoring the importance of forest as habitat. In contrast, movement rates were higher in open pastures, mainly during dispersal. Our study underscores the scarcity of research on puma space use and dispersal in South America and reveals partial divergences in dispersal behaviors compared to North America and temperate regions, especially concerning dispersal ages. Furthermore, we give the first steps in presenting how land cover and human infrastructure affect the movement of this apex predator in a tropical ecosystem, an important subsidy for land use management. We call for more comprehensive studies on the movement ecology of carnivores combined with long-term population monitoring, to allow linking individual behavior with metapopulation dynamics and landscape connectivity and drawing more effective measures to sustain their populations. Full article

Background: Monitoring genetic parameters is important for setting effective conservation and management strategies, particularly for small, fragmented, and isolated populations. Small, isolated populations face increased rates of genetic drift and inbreeding, which increase extinction risk especially when gene flow is limited. Methods: Here, we applied a Genotyping-in-Thousands by sequencing (GT-seq) panel to inform recovery action for the federally threatened northern Idaho ground squirrel (Urocitellus brunneus). We evaluated genetic diversity, structure, connectivity, and effective population size to address species recovery goals. Results: We delineated three types of conservation units: (1) three evolutionarily significant units that represent long-term population structure and variation, (2) nine management units that reflect current demographic connectivity and restrictions to gene flow, and (3) three adaptive units that capture adaptive differentiation across the species range. Effective population sizes per management unit were small overall (mean 38.16, range 2.3–220.9), indicating that recovery goals of 10 subpopulations with N_e > 500 have not been reached. Conclusions: Our results support the maintenance of connectivity within evolutionarily significant units through the restoration of dispersal corridors. Next steps could include further sampling of some subpopulations with low sample sizes, unsampled subpopulations, and subpopulations that are geographically isolated. Genotyping future samples with the same GT-seq panel would help to detect dispersal, assess effective population size, monitor the effects of inbreeding, and evaluate adaptive differentiation to monitor the effects of management action and environmental change. Full article

Animal populations, even among common species, often exhibit demographic heterogeneity. This is particularly evident in species with metapopulation structures, where geographically distinct subpopulations experience varying degrees of inbreeding due to limited interbreeding. A phenomenon termed ‘negative ecology’ highlights cases where species, despite suitable habitat availability, display fragmented distributions within small geographic areas (<20 km²). These subpopulations, however, do not conform to classic metapopulation dynamics, as even vagile species such as birds can theoretically move freely between them. Similar patterns emerge at larger scales (>100 km²) in birds and butterflies, suggesting ecological constraints—either abiotic or biotic—underpin these structured distributions. Understanding these constraints is essential, particularly in conservation efforts. The principles of positive (extant) and negative (locally absent/extinct) ecology have profound implications for species re-introductions, as historical occupancy does not guarantee successful re-establishment. Abiotic and biotic factors may hinder the recolonization of previously inhabited or entirely new habitats. This article primarily explores the ecological forces shaping such fragmented distributions in birds and butterflies, two especially well-studied taxa in the UK and mainland Europe, in the hope that such a new perspective may thereby contribute to broader conservation and ecological restoration strategies. Full article

Genetic diversity determines evolutionary potential. Without a variable genome, natural selection cannot act. Habitat fragmentation is the single largest threat to global biodiversity, as it reduces or eliminates gene flow among populations, thereby increasing the erosion of genetic diversity through random genetic drift. The loss of adaptive capacity in small, isolated populations is irreversible without gene flow and the ensuing genetic rescue. Without habitat connectivity, populations cannot expand or contract into refugia, an increasingly vital capacity under climate change. Here, I review what we have learned from organisms found in naturally fragmented landscapes. Metapopulation theory has played a seminal role in this goal. However, extending this theory to anthropogenically fragmented habitats has been a challenge. Single-species approaches cannot elucidate the impacts of habitat fragmentation on entire communities, composed of species with diverse interactions—mutualisms, facilitations and predator–prey dynamics—and proper ecosystem functioning. To overcome the limitation of single-species studies, metacommunity and metaecosystem ideas have emerged. The spatial extent and configuration of habitat patches will determine which species remain in altered landscapes. Changes to species interactions, community structure and ecosystem processes will follow. Ecosystem function determines ecosystem viability, and losses of keystone or foundation species will have cascading effects. Genomic tools can track the effect of landscape changes on population and movement dynamics, the maintenance of genetic resources and the persistence probabilities of individual species in the context of the communities in which they are embedded. Landscape genetics combines landscape features and population genetics to quantify how species use diverse landscapes and is now a powerful tool to assess the causes and consequences of habitat fragmentation for interacting species in fragmented ecosystems. Full article

Habitat fragmentation is one of the most critical threats to species conservation, particularly for those with strict habitat preferences and specialized feeding and reproductive behaviors. In such cases, dispersal is essential for gene flow, playing a significant role in determining metapopulation dynamics and stability. This is precisely the case for many Lepidoptera, such as the dusky large blue butterfly (Phengaris nausithous), whose larvae feed on a single host plant (Sanguisorba officinalis) before completing their life cycle as social parasites of Myrmica ants. In Spain, P. nausithous is a vulnerable species found only in certain areas along the mountainous fringe of the northern plateau. In one of these regions (northern Palencia province), five populations separated by distances ranging from 2 to 40 km were studied using microsatellite markers, along with a control population located 200 km away (Soria province), to assess their genetic structure and population dynamics. The results revealed a lack of connectivity and pronounced genetic structuring in four of the studied populations. Only two populations within the Montaña Palentina Natural Park exhibited clear connectivity, demonstrating high gene flow between them. This could be explained by the availability and stability of S. officinalis patches, which may function as stepping stones. This study confirms the challenges posed by habitat fragmentation but also demonstrates that Phengaris nausithous can maintain gene flow between relatively distant areas. At a local level, the results provide the first evidence that the populations studied within the western part of the Montaña Palentina Natural Park belong to a single metapopulation, which may encompass the entire natural park. Full article

Species are disappearing worldwide, and it is likely that the rate of their disappearance will increase. The most important factors responsible for this are assumed to be changes in climate and land use. To determine the probability of extinction of a given species, it must be viewed as a metapopulation composed of many populations. In plants, seeds are spread by wind or water (passive dispersers), unlike active dispersers, which can actively look for a suitable site of their species. Thus, while active dispersers can locate a suitable site, passive dispersers often fail to arrive at a suitable site. The following question arises: is it better for the survival of a metapopulation of passive dispersers to concentrate on conserving a few large populations, each of which will produce many propagules, or on many small populations, each of which will produce only few propagules? Here, we address the question of which of these strategies will maximize the likelihood of the survival of such a metapopulation, using orchids as a model. We concluded that small populations should be preferentially preserved. Small populations are more numerous and more likely to occur more widely in the region studied and therefore a larger proportion of the seeds they produce is more likely to land in suitable habitats than that produced by the fewer large populations. For conservation, there is a possibility to extend the results to other taxa. However, this must be carried out with caution and must consider the taxon in question. Full article