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We investigate the plasmon-mediated nonlinear dynamics and the optics of a laser emission of random nanoemitters (NEs) embedded in a two-dimensional (2D) lattice of conducting nanorings (NRs) enhanced by plasmon–polariton (PP) excitations. The interaction of quantum NEs with the PP field in the NRs perturbs the dynamics of the electronic populations in NEs, leading to a significant dependence of laser generation (dynamics) on the plasma frequency ωp of PP. This results in a strong coupling of NE field emission with the PP field and sharp variations of the average current in the NR lattice. The phase transition in the system was found when the macroscopic structures of PP fields are excited simultaneously in different regions of the system if ωp (control parameter) reaches critical value ωc. We have established the analytical dependence of the PP current I = I(ωp/ωc) on the plasma frequency, which is in excellent agreement with the results of numerical simulations. This effect may allow the design of new types of PP active devices with the use of conducting NRs in modern nanoelectronics. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the Floquet mean-field dynamics and Floquet surface hopping approaches to study the nonadiabatic dynamics in periodically driven solid systems. We demonstrate that these two approaches can be formulated in both real and reciprocal spaces. Using the two approaches, we are able to simulate the interaction between electronic carriers and phonons under periodic drivings, such as strong light–matter interactions. Employing the Holstein and Peierls models, we show that strong light–matter interactions can effectively modulate the dynamics of electronic population and mobility. Notably, our study demonstrates the feasibility and effectiveness of modeling low-momentum carriers' interactions with phonons using a truncated reciprocal space basis, an approach impractical in real space frameworks. Moreover, we reveal that even with a significant truncation, carrier populations derived from surface hopping maintain greater accuracy compared to those obtained via mean-field dynamics. These results underscore the potential of our proposed methods in advancing the understanding of carrier–phonon interactions in various periodically driven materials. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of excited-state vibrational energy relaxation in photosynthetic pigments is crucial for elucidating the mechanisms underlying energy transfer processes in light-harvesting complexes. Utilizing advanced femtosecond broadband transient fluorescence (TF) spectroscopy, we explored the excited-state vibrational dynamics of Chlorophyll-a (Chl-a) both in solution and within the light-harvesting complex II (LHCII). We discovered a vibrational cooling (VC) process occurring over ∼6 ps in Chl-a in ethanol solution following Soret band excitation, marked by a notable ultrafast TF blueshift and spectral narrowing. This VC process, crucial for regulating the vibronic lifetimes, was further elucidated through the direct observation of the population dynamics of higher vibrational states within the Qy electronic state. Notably, Chl-a within LHCII demonstrated significantly faster VC dynamics, unfolding within a few hundred femtoseconds and aligning with the ultrafast energy transfer processes observed within the complex. Our findings shed light on the complex interaction between electronic and vibrational states in photosynthetic pigments, underscoring the pivotal role of vibrational dynamics in enabling efficient energy transfer within light-harvesting complexes. [ABSTRACT FROM AUTHOR]

The dynamics of the sub-Ohmic spin-boson model under polarized initial conditions at finite temperatures is investigated by employing both analytical tools and the numerically accurate hierarchical equations of motion-tensor train method. By analyzing the features of nonequilibrium dynamics, we discovered a bifurcation phenomenon, which separates two regimes of the dynamics. It is found that before the bifurcation time, increasing temperature slows down the population dynamics, while the opposite effect occurs after the bifurcation time. The dynamics is highly sensitive to both initial preparation of the bath and thermal effects. [ABSTRACT FROM AUTHOR]

As an emerging technology in liquid inactivation, one of the main challenges of pulsed electric fields (PEFs) inactivation lies in quantitatively describing and predicting its lethality to microorganisms. However, due to its cross-scaled complexity and the consequent numerous regulatory factors, there is currently still no unified framework to understand the PEF dose–response relationship and the population dynamics theoretically. In this study, a simple yet powerful model from multiscale coarse-graining method is proposed to simulate the bacterial inactivation in suspensions during PEF processing. The complex dose–response effects at the macroscale are successfully reconstructed from simple evolution rules and several coarse-graining parameters, while considering the damage and death of a single bacterium at the microscale. Our model uncovers the seemingly chaotic and even controversial dose–response relationship of PEF in literatures and systematically explores the regulatory effect of experimental parameters in a unified framework. One of the interesting findings is that PEF with shorter pulsed width enhances lethality and reduces the minimal inhibitory time at a constant energy output per pulse, owing to the phase transitions in three bacterial population dynamics (Bistability mode, Avalanche mode, and Hybrid mode). Our study provides a new insight for numerically modeling PEF lethality in liquid inactivation and could serve as a guide for dosage management in practical applications. [ABSTRACT FROM AUTHOR]

Predicting the effects of warming temperatures on the abundance and distribution of organisms under future climate scenarios often requires extrapolating species-environment correlations to climatic conditions not currently experienced by a species, which can result in unrealistic predictions. For poikilotherms, incorporating species' thermal physiology to inform extrapolations under novel thermal conditions can result in more realistic predictions. Furthermore, models that incorporate species and spatial dependencies may improve predictions by capturing correlations present in ecological data that are not accounted for by predictor variables. Here, we present a joint species, spatially dependent physiologically guided abundance (jsPGA) model for predicting multispecies responses to climate warming. The jsPGA model uses a basis function approach to capture both species and spatial dependencies. We apply the jsPGA model to predict the response of eight fish species to projected climate warming in thousands of lakes in Minnesota, USA. By the end of the century, the cold-adapted species was predicted to have high probabilities of extirpation across its current range-with 10% of lakes currently inhabited by this species having an extirpation probability >0.90. The remaining species had varying levels of predicted changes in abundance, reflecting differences in their thermal physiology. Though the model did not identify many strong species dependencies, the variation in estimated spatial dependence across species suggested that accounting for both dependencies was important for predicting the abundance of these fishes. The jsPGA model provides a new tool for predicting changes in the abundance, distribution, and extirpation probability of poikilotherms under novel thermal conditions.

By employing the numerically accurate multiple Davydov Ansatz (mDA) formalism in combination with the thermo-field dynamics (TFD) representation of quantum mechanics, we systematically explore the influence of three parameters—temperature, photonic-mode detuning, and qubit–phonon coupling—on population dynamics and absorption spectra of the Holstein–Tavis–Cummings (HTC) model. It is found that elevated qubit–phonon couplings and/or temperatures have a similar impact on all dynamic observables: they suppress the amplitudes of Rabi oscillations in photonic populations as well as broaden the peaks and decrease their intensities in the absorption spectra. Our results unequivocally demonstrate that the HTC dynamics is very sensitive to the concerted variation of the three aforementioned parameters, and this finding can be used for fine-tuning polaritonic transport. The developed mDA-TFD methodology can be efficiently applied for modeling, predicting, optimizing, and comprehensively understanding dynamic and spectroscopic responses of actual molecular systems in microcavities. [ABSTRACT FROM AUTHOR]

Scaffolded molecular networks are important building blocks in biological pigment–protein complexes, and DNA nanotechnology allows analogous systems to be designed and synthesized. System–environment interactions in these systems are responsible for important processes, such as the dissipation of heat and quantum information. This study investigates the role of nanoscale molecular parameters in tuning these vibronic system–environment dynamics. Here, genetic algorithm methods are used to obtain nanoscale parameters for a DNA-scaffolded chromophore network based on comparisons between its calculated and measured optical spectra. These parameters include the positions, orientations, and energy level characteristics within the network. This information is then used to compute the dynamics, including the vibronic population dynamics and system–environment heat currents, using the hierarchical equations of motion. The dissipation of quantum information is identified by the system's transient change in entropy, which is proportional to the heat currents according to the second law of thermodynamics. These results indicate that the dissipation of quantum information is highly dependent on the particular nanoscale characteristics of the molecular network, which is a necessary first step before gleaning the systematic optimization rules. Subsequently, the I-concurrence dynamics are calculated to understand the evolution of the vibronic system's quantum entanglement, which are found to be long-lived compared to these system–bath dissipation processes. [ABSTRACT FROM AUTHOR]

Ecological and evolutionary theories have proposed that species traits should be important in mediating species responses to contemporary climate change; yet, empirical evidence has so far provided mixed evidence for the role of behavioral, life history, or ecological characteristics in facilitating or hindering species range shifts. As such, the utility of trait-based approaches to predict species redistribution under climate change has been called into question. We develop the perspective, supported by evidence, that trait variation, if used carefully can have high potential utility, but that past analyses have in many cases failed to identify an explanatory value for traits by not fully embracing the complexity of species range shifts. First, we discuss the relevant theory linking species traits to range shift processes at the leading (expansion) and trailing (contraction) edges of species distributions and highlight the need to clarify the mechanistic basis of trait-based approaches. Second, we provide a brief overview of range shift-trait studies and identify new opportunities for trait integration that consider range-specific processes and intraspecific variability. Third, we explore the circumstances under which environmental and biotic context dependencies are likely to affect our ability to identify the contribution of species traits to range shift processes. Finally, we propose that revealing the role of traits in shaping species redistribution may likely require accounting for methodological variation arising from the range shift estimation process as well as addressing existing functional, geographical, and phylogenetic biases. We provide a series of considerations for more effectively integrating traits as well as extrinsic and methodological factors into species redistribution research. Together, these analytical approaches promise stronger mechanistic and predictive understanding that can help society mitigate and adapt to the effects of climate change on biodiversity.

Stochastic chemical kinetics is a widely used formalism for studying stochasticity of chemical reactions inside single cells. Experimental studies of reaction networks are generally performed with cells that are part of a growing population, yet the population context is rarely taken into account when models are developed. Models that neglect the population context lose their validity whenever the studied system influences traits of cells that can be selected in the population, a property that naturally arises in the complex interplay between single-cell and population dynamics of cell fate decision systems. Here, we represent such systems as absorbing continuous-time Markov chains. We show that conditioning on non-absorption allows one to derive a modified master equation that tracks the time evolution of the expected population composition within a growing population. This allows us to derive consistent population dynamics models from a specification of the single-cell process. We use this approach to classify cell fate decision systems into two types that lead to different characteristic phases in emerging population dynamics. Subsequently, we deploy the gained insights to experimentally study a recurrent problem in biology: how to link plasmid copy number fluctuations and plasmid loss events inside single cells to growth of cell populations in dynamically changing environments. [ABSTRACT FROM AUTHOR]

Obtaining robust estimates of population abundance is a central challenge hindering the conservation and management of many threatened and exploited species. Close-kin mark-recapture (CKMR) is a genetics-based approach that has strong potential to improve the monitoring of data-limited species by enabling estimates of abundance, survival, and other parameters for populations that are challenging to assess. However, CKMR models have received limited sensitivity testing under realistic population dynamics and sampling scenarios, impeding the application of the method in population monitoring programs and stock assessments. Here, we use individual-based simulation to examine how unmodeled population dynamics and aging uncertainty affect the accuracy and precision of CKMR parameter estimates under different sampling strategies. We then present adapted models that correct the biases that arise from model misspecification. Our results demonstrate that a simple base-case CKMR model produces robust estimates of population abundance with stable populations that breed annually; however, if a population trend or non-annual breeding dynamics are present, or if year-specific estimates of abundance are desired, a more complex CKMR model must be constructed. In addition, we show that CKMR can generate reliable abundance estimates for adults from a variety of sampling strategies, including juvenile-focused sampling where adults are never directly observed (and aging error is minimal). Finally, we apply a CKMR model that has been adapted for population growth and intermittent breeding to two decades of genetic data from juvenile lemon sharks (Negaprion brevirostris) in Bimini, Bahamas, to demonstrate how application of CKMR to samples drawn solely from juveniles can contribute to monitoring efforts for highly mobile populations. Overall, this study expands our understanding of the biological factors and sampling decisions that cause bias in CKMR models, identifies key areas for future inquiry, and provides recommendations that can aid biologists in planning and implementing an effective CKMR study, particularly for long-lived data-limited species.

The coexistence of obligate mutualists is often precariously close to tipping points where small environmental changes can drive catastrophic shifts in species composition. For example, microbial ecosystems can collapse by the decline of a strain that provides an essential resource on which other strains cross-feed. Here, we show that tipping points, ecosystem collapse, bistability and hysteresis arise even with very weak (non-obligate) mutualism provided the population is spatially structured. Based on numeric solutions of a metacommunity model and mean-field analyses, we demonstrate that weak mutualism lowers the minimal dispersal rate necessary to avoid stochastic extinction, while species need to overcome a mean threshold density to survive in this low dispersal rate regime. Our results allow us to make numerous predictions for mutualistic metacommunities regarding tipping points, hysteresis effects, and recovery from external perturbations, and let us draw general conclusions for ecosystems even with random, not necessarily mutualistic, interactions and systems with density-dependent dispersal rather than direct mutualistic interactions.

The hypothesis of resource-limitation of population growth of Pseudocalanus sp. was tested in Dabob Bay, Washington state. Five independent indices were inconsistent with the resource-limitation hypothesis: (1) interannual variations in abundance depend on the initial conditions, independent of within-year fluctuations in resources, (2) generation time in the field correspond to those for food-satiated copepods, (3) seasonal changes in prosome length are consistent with those for food-satiated animals, (4) ambient phytoplankton abundance nearly always meets or exceeds the critical concentration fo growth, (5) females reproduce continuously, exhibiting only damped seasonal changes in reproductive rate as assessed from a modified egg ratio method. The food limitation paradigm is not applicable to Pseudocalanus sp., for which predation is a more likely mechanism of population regulation.

We develop a theory of singlet fission in carotenoid dimers. Following photoexcitation of the "bright" state (i.e., a singlet electron–hole pair) in a single carotenoid, the first step in the singlet fission process is ultrafast intramolecular conversion into the highly correlated "dark" (or 2Ag) state. This state has both entangled singlet triplet-pair and charge-transfer character. Our theory is predicated on the assumption that it is the singlet triplet-pair component of the "dark" state that undergoes bimolecular singlet fission. We use valence bond theory to develop a minimal two-chain model of the triplet-pair states. The single and double chain triplet-pair spectra are described, as this helps explain the dynamics and the equilibrated populations. We simulate the dynamics of the initial entangled pair state using the quantum Liouville equation, including both spin-conserving and spin-nonconserving dephasing processes. By computing the intrachain and interchain singlet, triplet, and quintet triplet-pair populations, we show that singlet fission critically depends on the interchain coupling and the driving potential (that determines endothermic vs exothermic fission). [ABSTRACT FROM AUTHOR]

We consider a diffusive Rosenzweig–MacArthur predator–prey model in the situation when the prey diffuses at a rate much smaller than that of the predator. In a certain parameter regime, the existence of fronts in the system is known: the underlying dynamical system in a singular limit is reduced to a scalar Fisher–KPP (Kolmogorov–Petrovski–Piskunov) equation and the fronts supported by the full system are small perturbations of the Fisher–KPP fronts. The existence proof is based on the application of the Geometric Singular Perturbation Theory with respect to two small parameters. This paper is focused on the stability of the fronts. We show that, for some parameter regime, the fronts are spectrally and asymptotically stable using energy estimates, exponential dichotomies, the Evans function calculation, and a technique that involves constructing unstable augmented bundles. The energy estimates provide bounds on the unstable spectrum which depend on the small parameters of the system; the bounds are inversely proportional to these parameters. We further improve these estimates by showing that the eigenvalue problem is a small perturbation of some limiting (as the modulus of the eigenvalue parameter goes to infinity) system and that the limiting system has exponential dichotomies. Persistence of the exponential dichotomies then leads to bounds uniform in the small parameters. The main novelty of this approach is related to the fact that the limit of the eigenvalue problem is not autonomous. We then use the concept of the unstable augmented bundles and by treating these as multiscale topological structures with respect to the same two small parameters consequently as in the existence proof, we show that the stability of the fronts is also governed by the scalar Fisher–KPP equation. Furthermore, we perform numerical computations of the Evans function to explicitly identify regions in the parameter space where the fronts are spectrally stable. [ABSTRACT FROM AUTHOR]

Ecological interactions between species can affect the performance of individuals, influence ecological and evolutionary dynamics of populations, and ultimately shape community structure. Therefore, documenting and studying interactions is necessary for a better comprehension of ecological patterns. Yet, sampling interactions in the field is challenging. Even with extensive sampling efforts we can hardly obtain a comprehensive picture of which species interact with each other. Such missing interactions can produce substantial gaps that affect how we perceive and interpret the network formed by species interactions and the roles of individual species within those networks. In this study we propose two methods that combine data on species interactions with information on species traits and phylogenies to estimate potentially missing interactions. We use one of the largest datasets on plant‐frugivore interactions, depicting thousands of interactions between birds and plants in the Atlantic Forest hotspot, to test those methods. Then, we analyze how adding newly estimated interactions change the network's overall structure and the topological importance of each species within the seed‐dispersal network. We show that estimated missing interactions more than tripled the number of interactions in the network and impact the general topological properties of the network increasing nestedness and reducing modularity. Both methods generated networks with a similar structure and were effective in estimating new interactions, accurately predicting known interactions without overestimating interactions in place of true absences. More importantly, added interactions changed our perception on the topological role of species, with several undersampled species earning novel interactions and becoming more central to network structure. This shows that estimating missing interactions can be helpful to get a more complete idea of how a network may look like, besides helping to inform which interactions should be the focus of further sampling efforts. [ABSTRACT FROM AUTHOR]

The Lesser Rhea (Rhea pennata), a large flightless bird native to South America, held historical significance as a vital resource for Patagonian hunter–gatherer societies. Despite the species' cultural and ecological importance, the historical population dynamics of R. pennata remain poorly understood. Although present in the archaeological record, its abundance is not consistently documented and the reasons remain unclear. This study investigates the late Holocene population trends of R. pennata using ancient DNA analysis. By analyzing complete mitochondrial genome sequences from dated archaeological specimens, we reveal a significant population increase from 700 to 500 years Before Present (BP), followed by a period of relative stability from 500 to 300 years BP. Subsequently, a subtle decline in population size is observed, coinciding with the arrival of European settlers; however, due to considerable uncertainty in population estimates, definitive conclusions regarding this decline are challenging to make. Historical records indicate heightened rhea hunting during this period, coterminous with a decrease in the abundance of rhea eggshell fragments. It is suggested that climatic factors may have influenced these population dynamics, particularly favoring rhea population growth from 700 to 500 years BP. This study contributes to our understanding of the historical ecology and human‐rhea interactions in Patagonia, emphasizing the importance of interdisciplinary approaches in reconstructing past population dynamics. [ABSTRACT FROM AUTHOR]

In Chile, Piscirickettsia salmonis contains two genetically isolated genogroups, LF-89 and EM-90. However, the impact of a potential co-infection with these two variants on Salmonid Rickettsial Septicemia (SRS) in Atlantic salmon (Salmo salar) remains largely unexplored. In our study, we evaluated the effect of P. salmonis LF-89-like and EM-90-like co-infection on post-smolt Atlantic salmon after an intraperitoneal challenge to compare changes in disease dynamics and host immune response. Co-infected fish had a significantly lower survival rate (24.1%) at 21 days post-challenge (dpc), compared with EM-90-like single-infected fish (40.3%). In contrast, all the LF-89-like single-infected fish survived. In addition, co-infected fish presented a higher presence of clinical lesions than any of the single-infected fish. The gene expression of salmon immune-related biomarkers evaluated in the head kidney, spleen, and liver showed that the EM-90-like isolate and the co-infection induced the up-regulation of cytokines (e.g., il-1β, ifnγ, il8, il10), antimicrobial peptides (hepdicin) and pattern recognition receptors (PRRs), such as TLR5s. Furthermore, in serum samples from EM-90-like and co-infected fish, an increase in the total IgM level was observed. Interestingly, specific IgM against P. salmonis showed greater detection of EM-90-like antigens in LF-89-like infected fish serum (cross-reaction). These data provide evidence that P. salmonis LF-89-like and EM-90-like interactions can modulate SRS disease dynamics in Atlantic salmon, causing a synergistic effect that increases the severity of the disease and the mortality rate of the fish. Overall, this study contributes to achieving a better understanding of P. salmonis population dynamics. [ABSTRACT FROM AUTHOR]

Many industries are required to perform population viability analysis (PVA) during the consenting process for new developments to establish potential impacts on protected populations. However, these assessments rarely account for density‐dependent regulation of demographic rates. Excluding density‐dependent regulation from PVA‐based impact assessments is often assumed to provide a maximum estimate of impact and therefore offer a precautionary approach to assessment. However, there is also concern that this practice may unnecessarily impede the development of important industries, such as offshore renewable energy. In this study, we assess density‐dependent regulation of breeding success in 31 populations of seabird. We then quantify the strength and form of this regulation using eight different formulations. Finally, we use PVA to examine how each formulation influences the recreation of observed dynamics (i.e. model validation), as well as the predicted absolute and relative population response to an extrinsic threat (i.e. model projection). We found evidence of both negative (n = 3) and positive (n = 5) regulation of seabird breeding success. In populations exhibiting negative regulation, excluding density‐dependent regulation from PVA‐based impact assessment allowed uncontrolled population growth, such that model outcomes became biologically implausible. By contrast, in populations exhibiting positive regulation, excluding density‐dependent regulation provided an appropriate reconstruction of observed dynamics, but population decline was underestimated in some populations. We find that multiple formulations of density dependence perform comparably at the detection, validation and projection stages of analysis. However, we tentatively recommend using a log‐linear or Weibull distribution to describe density‐dependent regulation of seabird breeding success in impact assessments to balance accuracy with caution. Finally, we show that relative PVA metrics of impact assessment cannot necessarily be used to overcome PVA misspecification by assuming density independence in positively regulated populations. Synthesis and applications: We suggest that a density‐dependent approach when performing PVA‐based assessments for seabird populations will prevent biologically unrealistic, unconstrained population growth and therefore ensure meaningful PVA metrics in populations experiencing negative regulation. It will also maintain a precautionary approach for populations experiencing positive regulation, crucial when estimating impacts for these more vulnerable populations. These conclusions have immediate international application within the consenting processes for marine industries. [ABSTRACT FROM AUTHOR]

Recent changes in climate and human land‐use have resulted in alterations of the geographic range of many species, including human pathogens. Geographic range expansion and population growth of human pathogens increase human disease risk. Relatively little empirical work has investigated the impact of range changes on within‐population variability, a contributor to both colonization success and adaptive potential, during the precise time in which populations are colonized. This is likely due to the difficulties of collecting appropriate natural samples during the dynamic phase of migration and colonization. We systematically collected blacklegged ticks (Ixodes scapularis) across New York State (NY), USA, between 2006 and 2019, a time period coinciding with a rapid range expansion of ticks and their associated pathogens including Borrelia burgdorferi, the etiological agent of Lyme disease. These samples provide a unique opportunity to investigate the population dynamics of human pathogens as they expand into novel territory. We observed that founder effects were short‐lived, as gene flow from long‐established populations brought almost all B. burgdorferi lineages to newly colonized populations within just a few years of colonization. By 7 years post‐colonization, B. burgdorferi lineage frequency distributions were indistinguishable from long‐established sites, indicating that local B. burgdorferi populations experience similar selective pressures despite geographic separation. The B. burgdorferi lineage dynamics elucidate the processes underlying the range expansion and demonstrate that migration into, and selection within, newly colonized sites operate on different time scales. [ABSTRACT FROM AUTHOR]

Colonization of the infant gut is an important developmental process characterized by high carriage of antimicrobial resistance genes (ARGs) and high abundances of pathobionts. The horizontal transfer of ARGs to pathogenic bacteria represents a major public health concern. However, there is still a paucity of longitudinal studies surveilling ARGs in healthy infant guts at high temporal resolution. Furthermore, we do not yet have a clear view of how temporal variation in ARG carriage relates to the dynamics of specific bacterial populations, as well as community virulence potential. Here, we performed deep shotgun metagenomic sequencing of monthly fecal samples from a cohort of 12 infants, covering the first year of life to interrogate the infant gut microbiome for ARG content. We further relate ARG dynamics to the dynamics of taxa, virulence potential, as well as the potential for ARG mobilization. We identify a core resistome dominated by efflux systems typically associated with Enterobacteriaceae. Overall ARG carriage declined over the first year of life and showed strong contemporaneous correlation with the population dynamics of Proteobacteria. Furthermore, the majority of ARGs could be further mapped to metagenome-assembled genomes (MAGs) classified to this phylum. We were able to assign a large number of ARGs to E. coli by correlating the temporal dynamics of individual genes with species dynamics, and we show that the temporal dynamics of ARGs and virulence factors are highly correlated, suggesting close taxonomic associations between these two gene classes. Finally, we identify ARGs linked with various categories of mobile genetic elements, demonstrating preferential linkage among mobility categories and resistance to different drug classes. While individual variation in ARG carriage is substantial during infancy there is a clear reduction over the first year of life. With few exceptions, ARG abundances closely track the dynamics of pathobionts and community virulence potential. These findings emphasize the potential for development of resistant pathogens in the developing infant gut, and the importance of effective surveillance in order to detect such events. [ABSTRACT FROM AUTHOR]

Spatial and trophic processes profoundly influence biodiversity, yet ecological theories often treat them independently. The theory of island biogeography and related theories on metacommunities predict higher species richness with increasing area across islands or habitat patches. In contrast, food-web theory explores the effects of traits and network structure on coexistence within local communities. Exploring the mechanisms by which landscape configurations interact with food-web dynamics in shaping metacommunities is important for our understanding of biodiversity. Here, we use a meta-food-web model to explore the role of landscape configuration in determining species richness and show that when habitat patches are interconnected by dispersal, more species can persist on smaller islands than predicted by classical theory. When patch sizes are spatially aggregated, this effect flattens the slope of the species–area relationship. Surprisingly, when landscapes have random patch-size distributions, the slope of the species–area relationships can even flip and become negative. This could be explained by higher biomass densities of lower trophic levels that then support species occupying higher trophic levels, which only persist on small and well-connected patches. This highlights the importance of simultaneously considering landscape configuration and local food-web dynamics to understand drivers of species–area relationships in metacommunities. This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'. [ABSTRACT FROM AUTHOR]

Introduction: Although estimate models have been proposed to determine free-roaming (both stray and semi-domiciled) dog populations, to date, no study has focused on the three major border areas of Brazil. Therefore, the present study assessed the free-roaming dog population of Foz do Iguaçu, a major far-west Brazilian city located in a three-border area (Brazil, Argentina, and Paraguay), which is considered among the top five Brazilian tourist destinations. Methods: Capture-release sampling was performed in three phases with a 6-month interval and 10-day duration of each phase, totaling 18 months, between 2018 and 2019. Results: A total of 1,273 dogs were estimated in the first [95% confidence interval (CI), 468-2,078 dogs], 904 in the second (95%CI, 452-1,355 dogs), and 1,564 in the third (95%CI, 521-2,607 dogs) capture phases in this area, suggesting a population density of 18.4 dogs/km² (6.1-30.6 dogs/km², 95% CI). Of all free-roaming dogs, 452/1,125 (40.2%) were stray with no confirmed ownership or household, whereas 672/1,125 (59.8%) had a known origin, among which 625/1,125 (55.6%) were semi-domiciled with ownership or a household, 36/1,125 (3.2%) were neighborhood dogs with maintainers, and 11/1,125 (1.0%) were owned by recycling material collectors and homeless individuals. The majority of the 1,125 dogs (862/1,125; 76.6%) had an ideal body condition score. The high outdoor access of owned dogs is likely caused by cultural behavior. However, because 533/1,125 (47.4%) of the free-roaming dogs presented with clinical abnormalities, irresponsible ownership may have negatively impacted dog health and welfare. Discussion: This study was the first to establish the density of free-roaming dogs, the ratio of stray and semi-domiciled dogs, and their dynamics over time in Foz do Iguaçu. The findings may serve as a warning for the high level of dog outdoor access and irresponsible guardianship, whichmay negatively a [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), commonly known as the fall armyworm, is one of the most serious pests of a wide range of plants including maize, soybean, cotton and rice. It is native to tropical and subtropical regions of the American continent and is considered as a quarantine pest for the European Union. Official surveys for the early detection of quarantine pests are performed annually in Greece. In the framework of that survey program, a network of pheromone traps for S. frugiperda has been established since 2019. From 2019 until 2022 no individuals of the pest were found in the traps. However, in autumn of 2023 the pest was first recorded in Greece. Male adults of the species were captured in those traps in seven regional units of south and central parts of Greece from September to December 2023. All the traps in which the pest was caught were placed in fields with Solanaceae plants, mainly tomatoes and eggplants. Moreover, larvae of the pest were also recorded in maize and tomato fields in Crete. From the collected data available it seems that the first adults caught in September most likely migrated to Greece from countries elsewhere in the region. [ABSTRACT FROM AUTHOR]

Responding to threats in the real world demands a sophisticated orchestration of freeze and flight behaviors dynamically modulated by the neural activity. While the medial prefrontal cortex-basolateral amygdala (mPFC-BLA) network is known to play a pivotal role in coordinating these responses, the mechanisms underlying its population dynamics remain vague. As traditional Pavlovian fear conditioning models fall short in encapsulating the breadth of natural escape behaviors, we introduce a novel dataset to bridge this gap, capturing the defensive strategies of mice against a spider robot in a natural-like environment. The adaptive escape behaviors and concurrent mPFC-BLA activity in eight mice were monitored using wireless local field potential (LFP) and video recordings, both individually and in groups. Our data offers a unique avenue to explore the neural dynamics that govern fear- and vigilance-induced threat responses in isolated and social contexts. Supplemented by detailed methodologies and validation, the dataset allows for the analysis of the transient neural oscillatory dynamics, with prospective implications for the fields of neuroscience, robotics, and artificial intelligence. [ABSTRACT FROM AUTHOR]

Climate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex Capra ibex. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction. [ABSTRACT FROM AUTHOR]

In this paper, we construct and analyze a mathematically reasonable and simplest population dynamics model based on Mark Granovetter’s idea for the spread of a matter (rumor, innovation, psychological state, etc.) in a population. The model is described by a one-dimensional difference equation. Individual threshold values with respect to the decision-making on the acceptance of a spreading matter are distributed throughout the population ranging from low (easily accepts it) to high (hardly accepts). Mathematical analysis on our model with some general threshold distributions (uniform; monotonically decreasing/increasing; unimodal) shows that a critical value necessarily exists for the initial frequency of acceptors. Only when the initial frequency of acceptors is beyond the critical, the matter eventually spreads over the population. Further, we give the mathematical results on how the equilibrium acceptor frequency depends on the nature of threshold distribution. [ABSTRACT FROM AUTHOR]

We present a rigorous mathematical analysis of a non‐convex optimal control problem for mosquito populations. The nonlinear model for the dynamics of the mosquito population takes in consideration the iterations among the immature (aquatic) subpopulation, the adult winged subpopulation, and the environment resources; the immature subpopulation is assumed to be age‐structured. Moreover, the action of certain control mechanisms on these subpopulations is also taken in account. The cost functional to be minimized is non‐convex. The proof of the existence of an optimal control is done by using fixed point arguments and a special minimizing sequence obtained with the help of Ekeland's variational principle. [ABSTRACT FROM AUTHOR]

Across the globe, many species of insects are facing population decline. This is largely driven by anthropogenic changes to the environment, including the widespread exposure of invertebrates to endocrine disrupting chemicals (EDCs), which impair fertility. To test whether generations of Drosophila melanogaster born from parents exposed to a common dietary EDC, equol, could recover reproductive function, we quantified the reproductive capacity of the two subsequent generations. Using a novel suite of flow cytometry assays to assess sperm functionality in real time, we find that sperm function is compromised across three generations, even after non-exposed in individuals contribute to the breeding population. Though the sex ratio alters in response to EDC exposure, favouring the survival of female offspring, most lineages with ancestral EDC exposure exhibit persistent subfertility in both the male and female. Male offspring with ancestral EDC exposure present with reduced fertility and dysfunctional spermatozoa, whereby spermatozoa are metabolically stressed, lack DNA integrity and present with permanent epigenetic alterations. Across generations, male and female offspring demonstrate distinct patterns of reproductive characteristics, depending upon the specific lineage of EDC exposure. Our results illustrate how dietary EDCs present in agricultural plants could promote transgenerational subfertility and contribute to declining insect populations. [ABSTRACT FROM AUTHOR]

East African countries accounted for ~ 10% of all malaria prevalence worldwide in 2022, with an estimated 23.8 million cases and > 53,000 deaths. Despite recent increases in malaria incidence, high-resolution genome-wide analyses of Plasmodium parasite populations are sparse in Kenya, Tanzania, and Uganda. The Kenyan-Ugandan border region is a particular concern, with Uganda confirming the emergence and spread of artemisinin resistant P. falciparum parasites. To establish genomic surveillance along the Kenyan-Ugandan border and analyse P. falciparum population dynamics within East Africa, we generated whole-genome sequencing (WGS) data for 38 parasites from Bungoma, Western Kenya. These sequences were integrated into a genomic analysis of available East African isolate data (n = 599) and revealed parasite subpopulations with distinct genetic structure and diverse ancestral origins. Ancestral admixture analysis of these subpopulations alongside isolates from across Africa (n = 365) suggested potential independent ancestral populations from other major African populations. Within isolates from Western Kenya, the prevalence of biomarkers associated with chloroquine resistance (e.g. Pfcrt K76T) were significantly reduced compared to wider East African populations and a single isolate contained the PfK13 V568I variant, potentially linked to reduced susceptibility to artemisinin. Overall, our work provides baseline WGS data and analysis for future malaria genomic surveillance in the region. [ABSTRACT FROM AUTHOR]

The banana mealybug Pseudococcus elisae Borchsenius (Hemiptera: Coccomorpha: Pseudococcidae) is a pest of economic importance in Cameroon that requires effective control practices, especially after the routinely used chlorpyrifos insecticide was banned in 2019. For effective mealybug control, it is imperative to understand their ecology in relation to banana growth stages and climate‐induced seasonal variations. Therefore, the influence of climatic variables and banana growth stages on a spatio‐temporal distribution of mealybugs in Esuke and Benoe banana plantations of the Cameroon Development Corporation in Tiko was assessed. A 60‐ha area was mapped in each plantation and divided into 12 plots of 5 ha each, which were further sub‐divided into four quadrants of 1.25 ha. A total of 10 banana suckers, 10 pre‐flowering, 10 flowering and 10 bunchy plants were sampled per quadrant. Monthly mealybug population dynamics were assessed across 2 years in 2021 and 2022 on lower or upper pseudostem, leaves and banana bunches. Significant yearly and monthly mealybug population variation on banana plants were observed, with more mealybugs in 2022 than 2021, and two monthly mealybug peaks in February and November (p < 0.001). Mealybug population was higher on banana bunches and lower or upper pseudostem than on leaves (p < 0.001). Mealybugs preferred bunchy plants than suckers or pre‐flowering and flowering plants, and exhibited clumped distribution with Taylor aggregation index (b) greater than one (p < 0.001). A simple linear regression revealed strong positive effects of high temperature on mealybug population ecology, while relative humidity and rainfall had inverse effects on the population of mealybug. These highlight the dynamics of banana mealybug population ecology under variable climatic conditions and banana growth stages, which provides valuable baseline information to facilitate developing effective control strategies for mealybugs in banana plantations. [ABSTRACT FROM AUTHOR]

In this work, we study the invasion dynamics of a stage-structured population located in a one-dimensional periodic lattice. With a biologically relevant hypothesis that the population diffuses in its immature stage, we derive a novel spatially heterogeneous population model with coupled local and nonlocal effects. Assuming a KPP-type structure, we obtain the existence and variational characterization of spreading speed by appealing to monotone dynamical system theories. Further, we study the dependence of the spreading speed on the dispersal rate of immature population; it turns out that there exists an optimal dispersal strategy to maximize the speed. Numerical simulations further suggest that such an optimal strategy is unique. [ABSTRACT FROM AUTHOR]

General anesthesia can impact a patient's memory and cognition by influencing hippocampal function. The CA1 and dentate gyrus (DG), serving as the primary efferent and gateway of the hippocampal trisynaptic circuit facilitating cognitive learning and memory functions, exhibit significant differences in cellular composition, molecular makeup, and responses to various stimuli. However, the effects of isoflurane-induced general anesthesia on CA1 and DG neuronal activity in mice are not well understood. In this study, utilizing electrophysiological recordings, we examined neuronal population dynamics and single-unit activity (SUA) of CA1 and DG in freely behaving mice during natural sleep and general anesthesia. Our findings reveal that isoflurane anesthesia shifts local field potential (LFP) to delta frequency and reduces the firing rate of SUA in both CA1 and DG, compared to wakefulness. Additionally, the firing rates of DG neurons are significantly lower than CA1 neurons during isoflurane anesthesia, and the recovery of theta power is slower in DG than in CA1 during the transition from anesthesia to wakefulness, indicating a stronger and more prolonged impact of isoflurane anesthesia on DG. This work presents a suitable approach for studying brain activities during general anesthesia and provides evidence for distinct effects of isoflurane anesthesia on hippocampal subregions. [ABSTRACT FROM AUTHOR]

Biased sex ratios among reproductive individuals are common in plants, but the underlying mechanisms, as well as the evolutionary consequences, are not well understood. The classical theory of Düsing and Fisher predicts an equal primary sex ratio at seed production, based on the selective advantage of the rare sex. Biased sex ratios among reproductive plants can arise from sexual dimorphism in survival and flowering. Sex ratio biases can also be present from the seed stage; in these cases, assumptions of Düsing's and Fisher's theory, for example, random mating or demographic equilibrium, are thought to be violated.We investigated mechanisms leading to female‐biased sex ratios in the arctic‐alpine dwarf willow Salix herbacea L. We studied sex ratios in three natural populations over 3 years as well as in 29 crosses (full‐sib families) under controlled conditions over four growth periods. We tested whether sex ratio was associated with habitat parameters (elevation and snowmelt time), or with germination, survival or flowering, and whether females and males differed in size or flowering that may cause observation bias.We detected a strong and consistent female bias, both in natural populations (sex ratio [proportion of females]: 0.71–0.82) and in our controlled experiment (overall sex ratio: 0.70–0‐72). Female bias became more pronounced with increasing elevation. Our data did not support sexual dimorphism in size or flowering. Family sex ratios varied largely (from 0.25 to 1), including many female‐biased families, unbiased families and two male‐biased families. Families with lower germination, seedling establishment, survival or flowering did not have stronger female bias, indicating that intrinsically higher survival or flowering in females does not explain overall female bias.Synthesis. Our results suggest that sex ratio bias in S. herbacea is already present in seeds and does not arise through intrinsic differences between sexes. Candidate mechanisms that can lead to both overall female bias and variation in sex ratio among families are meiotic drive or cyto‐nuclear interactions. The pioneer habit of Salix may lead to non‐equilibrium population dynamics that allow for the long‐term persistence of variable genetic sex ratio distortion systems that arise from genetic conflict. [ABSTRACT FROM AUTHOR]

Recent evidence suggests that individuals differ in foraging tactics and this variation is often linked to an individual's behavioural type (BT). Yet, while foraging typically comprises a series of search and handling steps, empirical investigations have rarely considered BT‐dependent effects across multiple stages of the foraging process, particularly in natural settings.In our long‐term sleepy lizard (Tiliqua rugosa) study system, individuals exhibit behavioural consistency in boldness (measured as an individual's willingness to approach a novel food item in the presence of a threat) and aggressiveness (measured as an individual's response to an 'attack' by a conspecific dummy). These BTs are only weakly correlated and have previously been shown to have interactive effects on lizard space use and movement, suggesting that they could also affect lizard foraging performance, particularly in their search behaviour for food.To investigate how lizards' BTs affect their foraging process in the wild, we supplemented food in 123 patches across a 120‐ha study site with three food abundance treatments (high, low and no‐food controls). Patches were replenished twice a week over the species' entire spring activity season and feeding behaviours were quantified with camera traps at these patches. We tracked lizards using GPS to determine their home range (HR) size and repeatedly assayed their aggressiveness and boldness in designated assays.We hypothesised that bolder lizards would be more efficient foragers while aggressive ones would be less attentive to the quality of foraging patches. We found an interactive BT effect on overall foraging performance. Individuals that were both bold and aggressive ate the highest number of food items from the foraging array. Further dissection of the foraging process showed that aggressive lizards in general ate the fewest food items in part because they visited foraging patches less regularly, and because they discriminated less between high and low‐quality patches when revisiting them. Bolder lizards, in contrast, ate more tomatoes because they visited foraging patches more regularly, and ate a higher proportion of the available tomatoes at patches during visits.Our study demonstrates that BTs can interact to affect different search and handling components of the foraging process, leading to within‐population variation in foraging success. Given that individual differences in foraging and movement will influence social and ecological interactions, our results highlight the potential role of BT's in shaping individual fitness strategies and population dynamics. [ABSTRACT FROM AUTHOR]

How can phenotypic plasticity promote or impede adaptive change and diversification? Answering this key question can be experimentally intractable, but closely related clonal species allow a direct approach: experimentally provoking phenotypic plasticity to assess the adaptive significance of both plastic traits and species differences. Two common Caribbean sponge species, Aplysina fulva and A. cauliformis , are nearly indistinguishable molecularly, and share growth form, habitat, and geographical range. This raises questions about species boundaries, within-species variability, and mechanisms of speciation. To distinguish phenotypic plasticity from genetic variation, and learn how plasticity might influence adaptive—and divergent—evolution, I: (i) quantified morphological and ecological characters, (ii) revealed phenotypic plasticity by growing clonemates in different environments, and (iii) related plastic morphological features to ecological function. Characters included skeletal fibre density, biomechanical properties, vulnerability to parasites and predators, wound healing, transport pathways, propagation by fragments, population dynamics, and growth and survival in settings differing in food, sunlight, predators, and water motion. Transplanting both species to a different environment elicited parallel plasticity in the same traits. Combined comparative and experimental data reveal integrated suites of ecologically relevant characters that clearly distinguish these species and allow interpretation of adaptive significance of plastic characters that may underlie divergence. [ABSTRACT FROM AUTHOR]

Patterns of cohort decline are key demographic traits that provide a unique temporal perspective vital to understanding population dynamics. The discovery of multidecadal lifespans in tropical surgeonfishes in the 1990s created a paradigm shift to the notion that they are highly vulnerable species with low population recovery rates; however, research into the mortality patterns of surgeonfishes (Acanthuridae) has been sparse until recently. Recent studies on this family have demonstrated an unusual (possibly unique), two‐phase pattern of adult catch‐at‐age, whereby there is a population‐level shift from higher‐than‐expected rates of decline early in life to lower‐than‐expected decline rates for the remainder of the lifespan. To examine the geographic and phylogenetic ubiquity of this pattern, we compiled age‐based information from demographic samples of 70 populations of 25 tropical species spanning the Indo‐Central Pacific and Central‐Western Atlantic. Overall, we found that 79% of populations exhibited strong biphasic patterns, including 88% of populations across the Indo‐Central Pacific. By accounting for empirical relationships instead of using linear catch curves or classical assumptions of natural population decay based on lifespan, we demonstrate that surgeonfishes have turnover times that are two to four times faster than previously believed. Faster turnover times may suggest a higher level of sustainability for surgeonfish fisheries throughout the global tropics than previously estimated. [ABSTRACT FROM AUTHOR]

In eastern Spain, Bonelli's eagle (Aquila fasciata) abundance has declined almost 50% in the last 25 years and, consequently, the species is listed as regionally endangered. Therefore, the aim of this study is to report the mortality causes of territorial breeding Bonelli's eagles, including the spatial and temporal patterns, and to assess the effects on population dynamics. From 2015–2023, we tracked 60 Bonelli's eagles via global positioning system‐global system for mobile communications (GPS‐GSM) telemetry; 33 of the eagles died (median survival time = 1,519 days). Survival did not differ in relation to sex, age at capture (subadult vs. adult birds), breeding site (coastland vs. inland territories), or transmitter's model. One‐year probability of survival (95% CI) was 0.716 (0.607–0.845); 2‐year survival was 0.640 (0.524–0.781); and 3‐year survival was 0.581 (0.464–0.729). Anthropogenic mortality (66.7% of cases) prevailed over natural (27.3%) and unknown causes (6.0%). Causes of mortality were intra‐ and interspecific predation (24.2% of cases), electrocution (18.2%), poisoning (15.1%), collision with power lines (9.1%), shooting (9.1%), drowning (9.1%), collision with other man‐made infrastructure (6.1%), and disease (3.0%). Deaths were most frequent during the early breeding season. Only 2 (6.1%) of 33 deaths recorded occurred within a protected area. Natural causes of mortality were more frequent away from the Mediterranean coast. In contrast, anthropogenic deaths were more frequent near the Mediterranean coast, where human population density is high. We estimated that probability of extirpation of the species in our study area is 17.8% in the next 50 years and 99.2% in 100 years. Nonetheless, a small reduction in adult mortality by ≥15% could prevent extirpation in the next 50 years. Therefore, actions to reduce adult mortality are urgently needed to preserve the Bonelli's eagle in eastern Spain. [ABSTRACT FROM AUTHOR]

Amplicon sequencing is an effective and increasingly applied method for studying viral communities in the environment. Here, we present vAMPirus, a user‐friendly, comprehensive, and versatile DNA and RNA virus amplicon sequence analysis program, designed to support investigators in exploring virus amplicon sequencing data and running informed, reproducible analyses. vAMPirus intakes raw virus amplicon libraries and, by default, performs nucleotide‐ and amino acid‐based analyses to produce results such as sequence abundance information, taxonomic classifications, phylogenies and community diversity metrics. The vAMPirus analytical framework leverages 16 different opensource tools and provides optional approaches that can increase the ratio of biological signal‐to‐noise and thereby reveal patterns that would have otherwise been masked. Here, we validate the vAMPirus analytical framework and illustrate its implementation as a general virus amplicon sequencing workflow by recapitulating findings from two previously published double‐stranded DNA virus datasets. As a case study, we also apply the program to explore the diversity and distribution of a coral reef‐associated RNA virus. vAMPirus is streamlined within Nextflow, offering straightforward scalability, standardization and communication of virus lineage‐specific analyses. The vAMPirus framework is designed to be adaptable; community‐driven analytical standards will continue to be incorporated as the field advances. vAMPirus supports researchers in revealing patterns of virus diversity and population dynamics in nature, while promoting study reproducibility and comparability. [ABSTRACT FROM AUTHOR]

Understanding whether hunting mortality is additive to or compensated by other mortality sources is at the heart of managing harvested populations. Long‐lived species are expected to exhibit hunting mortality additive to other sources of mortality, making them ideal candidates for population management through sport harvest. Previous studies on these processes have focussed on density‐dependent natural mortality compensating for hunting mortality, but when harvest occurs in distinct periods of the year, heterogeneity in hunting vulnerability between individuals could also lead to compensatory mortality between these periods. We explore this new idea using the case of the greater snow goose (Anser caerulescens atlantica), a harvested species whose population became overabundant in the late 20th century. To control this population, wildlife agencies liberalised hunting regulations with unprecedented actions such as special hunting seasons implemented in spring 1999 in Canada and in winter 2009 in the USA. To determine the relative impact of each measure on survival, we estimated survival of adult geese on a seasonal basis using 30 years of capture‐mark‐reencounter data in a joint live‐and‐dead‐encounter multievent model. We also used this quasi‐experimental set‐up to evaluate possible compensation in hunting mortality between seasons. We found that both special hunting seasons decreased goose survival in the seasons and periods in which they were implemented. However, survival increased during the spring hunting season after the establishment of the special winter hunting season in the USA in 2009. There was a negative relationship between annual spring and winter mortalities, suggesting that the increase in hunting mortality in winter was compensated by a reduction in spring mortality after 2009. Synthesis and applications: To our knowledge, we report the first documented instance of hunting mortality in one season being compensated by a reduction in hunting mortality in a subsequent season. We suggest that heterogeneity in hunting vulnerability among individuals, possibly linked to the presence of juveniles, may explain this phenomenon. A better knowledge of seasonal patterns and relationships between mortality components is needed to improve our understanding of population dynamics and management of harvested populations. [ABSTRACT FROM AUTHOR]

With a historical perspective, I reviewed the peer-reviewed scientific literature (and some gray literature, as needed) on European hare (Lepus europaeus) in the six countries already invaded by it: Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay. I covered the following topics: (a) Introduction, spread, and current distribution; (b) Life history, reproduction, and population dynamics; (c) Interactions with predators other than humans; (d) Interactions with scavengers; (e) Interactions with plants and herbivorous competitors; (f) Interactions with parasites and diseases; (g) Interactions with humans, including hunting, exports, and interference. Notoriously missing is the coverage of hare genetics and population dynamics and modeling. Another eyesore is the lack of an ecosystem approach to this invader, including not only biological aspects but the social-economic and cultural contexts that harbors it. [ABSTRACT FROM AUTHOR]

Superior competitors are known to regulate community structure by influencing competitive outcomes between species of inferior competitors with overlapping ecological niches. However, more research is needed to obtain a detailed understanding of the ecological process.We examined how the superior competitor Daphnia magna influenced competition–exclusion between two coexisting Brachionus rotifer species.Brachionus angularis was no longer the superior competitor when D. magna was introduced into the cultured Brachionus calyciflorus + B. angularis system. Small‐sized D. magna (1.6–1.9 mm in body length) mediated population dynamics and facilitated the persistence of the two Brachionus species, while large‐sized D. magna (2.0–2.3 mm in body length) excluded only B. angularis at the high food level (3 × 106 cells/ml Chlorella) or both rotifer species at the low food level (1 × 106 cells/ml Chlorella).These findings indicate that the different body sizes of a superior competitor species can reverse competitive results between inferior competitor species in relation to food abundance.Our results highlight the dynamic nature of populations in multispecies communities and the need to understand species interactions in relation to their environment. [ABSTRACT FROM AUTHOR]

Development and maintenance of neural architecture supporting learning and memory, as well as active storage of learnt information, are predicted to carry significant energetic costs. Here we explored whether the demands of learning about fitness-relevant stimuli come at a cost to the reproductive success of an insect model. Bumble bee (Bombus spp.) queens found nests alone, and early in the colony cycle must invest simultaneously in learning about rewarding floral resources and colony founding. We exposed queens of Bombus terrestris audax emerging from diapause to a 6-day reversal learning task and compared colony founding success of these individuals to two control groups that did not learn but received equal food. Additionally, we limited carbohydrate intake in half of queens across all treatments. Nutritionally stressed queens had a lower probability of egg laying, delayed nest initiation and lower offspring production compared with nutritionally unrestricted queens, suggesting resource availability at this life cycle stage is crucial to founding successful colonies and population growth. Nevertheless, potential energetic demands of learning did not reduce colony founding success in a laboratory set-up, even in nutritionally stressed groups. Our findings provide a rare real-world test of the costs associated with learning and suggest they do not affect reproductive potential in bumble bee queens. • Development and use of neural architecture carries potential energetic costs. • We test whether such costs compromise reproductive success in bumble bee queens. • The demands of learning did not affect colony founding success, even under stress. • Nutritional stress negatively affected egg laying and offspring production. • Resource-poor environments may affect bumble bee population dynamics. [ABSTRACT FROM AUTHOR]

Aim: Temporal variability in population growth rates is a fundamental property of natural populations with implications for almost any facet in ecology and evolution. Using the framework of nonlinear averaging, we test the hypothesis that the magnitude of short‐term variability in population growth rates is influenced by the long‐term means of climatic conditions. Location: The contiguous United States. Time period: 1970–2019. Major taxa studied: Birds. Methods: Our study encompassed 3941 populations of resident birds in 1335 localities across the contiguous United States. For each population, we quantified the standard deviation of annual growth rates over the relevant period and the corresponding long‐term mean values of annual temperature and precipitation. We further considered the effects of covariates known to influence temporal variability in population growth, namely the standard deviations of climatic variables, the lifespan and the preferred habitat (forest vs. non‐forest) of each species. The effects of climate and species traits on the variability in population growth rates were analysed using linear mixed‐effects models. Results: The magnitude of variability in population growth rate decreased with increasing the long‐term mean of annual precipitation and had a U‐shaped dependence on mean annual temperature. Variability in climatic conditions increased population growth variability, but this effect was weaker than the effect of the corresponding long‐term means. A long lifespan reduced the impact of climatic variability on the variability in population growth rates. Main conclusions: Our finding that the magnitude of variability in population growth rates is influenced by the long‐term characteristics of climatic conditions and species traits extends our perspective on the relationship between climate and population dynamics and should be taken into account in future assessments of spatial and temporal population responses to climate change. [ABSTRACT FROM AUTHOR]

Mandothi Wetlands located in district Jhajjar of Haryana, India is about 1000 acres of farmland, serves as a crucial habitat for numerous species of winter migratory birds. From December 2021 to March 2023, fortnightly periodic visits were made to the area by using scan sampling and point-cum-line transect methods. A total of 54 winter migratory birds' species were recorded including 33 genera, 19 families, and 8 orders. Order Charadriiformes was highly diverse with the presence of 17 species in the study area. Feeding guild analysis expressed that Insectivores were the dominant ones among all guilds. As per the IUCN Red List criteria, 48 species were classified as least concern (LC) whereas, 3 species were classified as Near Threatened (NT) i.e., Ferruginous Duck Aythya nyroca, Eurasian Curlew Numenius arquata, Curlew Sandpiper Calidris ferruginea, and 3 species were classified as Vulnerable (VU) such as Eastern Imperial Eagle Aquila heliaca, Greater Spotted Eagle Clanga clanga and Common Pochard Aythya ferina globally. Study area holds a significant role in sustaining the diversity of birds and also facing various stress factors thus it needs to be conserved. [ABSTRACT FROM AUTHOR]

The hypothesis of chaotic population dynamics was proposed in ecology by Robert May in the mid-1970s. At that time the idea was controversial, and it remains a fascinating and unsettled issue today. We report the results of a 20-year laboratory research programme that continued in the tradition of the pioneering ecologist Thomas Park using the Tribolium flour beetle model. We present biological evidence of complex population dynamics – including bifurcations, chaos, saddle nodes, phase switching, resonance effects, and multiple attractors – by using a low-dimensional difference equation model for Tribolium together with carefully designed, conducted, and statistically analysed experiments. The model, parameterized with data, also explains the results of historical Tribolium experiments, such as the classical competition studies of Thomas Park and his colleagues. Our research programme has inspired other studies using the Tribolium mathematical and laboratory model. This work was conducted by a multidisciplinary team, which included Jim Cushing. [ABSTRACT FROM AUTHOR]

The assembly and persistence of ecological communities can be understood as the result of the interaction and migration of species. Here we study a single community subject to migration from a species pool in which inter-specific interactions are organised according to a bipartite network. Considering the dynamics of species abundances to be governed by generalised Lotka–Volterra equations, we extend work on unipartite networks to we derive exact results for the phase diagram of this model. Focusing on antagonistic interactions, we describe factors that influence the persistence of the two guilds, locate transitions to multiple-attractor and unbounded phases, as well as identifying a region of parameter space in which consumers are essentially absent in the local community. [ABSTRACT FROM AUTHOR]