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Our understanding of ecosystem functioning is strongly linked to the study of predator–prey relationships and food web structures. However, trophic ecology has often focused on identifying taxonomic relationships and quantifying the biomass or energy ingested by consumers, but has often failed to integrate the importance of the nutritional quality of resources in ecological dynamics. Underlying this gap is the multi‐dimensional nature of resource quality which has hampered any consensus on the definition of resource nutritional quality. In this special issue, we aimed at gathering a subset of articles exemplifying the diversity of variables by which resources quality is quantified, the diversity of research topics that can be tackled in ecology – from physiological or evolutionary aspects to ecosystem processes – and propose some perspectives on the integration of nutritional quality within broader ecological concepts. Using a semi‐automated literature analysis, we map the current landscape of the 'resources nutritional quality' research of the last 30 years. We depict how it has been quantified through physical, biological or chemical indicators, the use of these parameters being largely dependent on the type of ecosystem studied and on the investigated ecological process. We then position the articles published in this special issue of Oikos within this landscape, showing they cover a small but relatively well representative subset of the domains of resources quality‐related issues. Articles in this special issue browse a range of individual and population‐level approaches (embracing evolutionary questions) to community related questions, include methodological issues and ecosystem‐wide approaches using trophic quality indicators as tracers of resources origin. Based on these studies and on the literature review, we identify a non‐exhaustive list of challenges and perspectives of research that we consider of highest priority in the large topic of trophic ecology. [ABSTRACT FROM AUTHOR]

The Shannon-Wiener index is a popular nonparametric metric widely used in ecological research as a measure of species diversity. We used the Web of Science database to examine cases where papers published from 1990 to 2015 mislabelled this index. We provide detailed insights into causes potentially affecting use of the wrong name 'Weaver' instead of the correct 'Wiener'. Basic science serves as a fundamental information source for applied research, so we emphasize the effect of the type of research (applied or basic) on the incidence of the error. Biological research, especially applied studies, increasingly uses indices, even though some researchers have strongly criticized their use. Applied research papers had a higher frequency of the wrong index name than did basic research papers. The mislabeling frequency decreased in both categories over the 25-year period, although the decrease lagged in applied research. Moreover, the index use and mistake proportion differed by region and authors' countries of origin. Our study also provides insight into citation culture, and results suggest that almost 50% of authors have not actually read their cited sources. Applied research scientists in particular should be more cautious during manuscript preparation, carefully select sources from basic research, and read theoretical background articles before they apply the theories to their research. Moreover, theoretical ecologists should liaise with applied researchers and present their research for the broader scientific community. Researchers should point out known, often-repeated errors and phenomena not only in specialized books and journals but also in widely used and fundamental literature. [ABSTRACT FROM AUTHOR]

The recent interest in the spatial structure and dynamics of populations motivated numerous theoretical and empirical studies of spatial synchrony, the tendency of populations to fluctuate in unison over regional areas. The first comprehensive framework applied to spatial synchrony was probably the one elaborated by P. A. P. Moran back in 1953. He suggested that if two populations have the same linear density-dependent structure, the correlation between them will be equal to that between the local density-independent conditions. Surprisingly, the consequences of violating the assumption that the dynamics of the populations are identical has received little attention. In this paper, making the assumption that population dynamics can be described by linear and stationary autoregressive processes, I show that the observed spatial synchrony between two populations can be decomposed into two multiplicative components: the demographic component depending on the values of the autoregressive coefficients, and the correlation of the environmental noise. The Moran theorem corresponds to the special case where the demographic component equals unity. Using published data, I show that the spatial variability in population dynamics may substantially contribute to the spatial variability of population synchrony, and thus should not be neglected in future studies. [ABSTRACT FROM AUTHOR]

Males and females often desynchronise their mating activity during the breeding season (intersexual phenological asynchrony). This suggests that the two sexes differentially use environmental cues to initiate seasonal reproduction, and climate change may cause phenological shifts in a sex‐specific manner, subsequently altering frequency distribution of mating attempts over time and influencing the emergence timing and recruitment success of juveniles. In this article, we tested these hypotheses through literature reviews and theoretical modelling. We found that the sex specificity of environmental cues and phenological shifts remain poorly understood in most sexually reproducing animal taxa because of sex‐specific publication bias and data limitations. Meanwhile, our theoretical model predicted that the ecological consequences of phenological shifts are sexually asymmetric, with earlier mating onset of males having generally greater negative effects on population growth than that of females. We therefore suggest that further research is necessary to collect and incorporate sex‐specific information on seasonal reproduction into the theory of phenological mismatch, for which previous work has mostly focused on interspecific trophic asynchrony. We also outline a future research agenda to better understand the consequences of sex‐specific phenological shifts on seasonal population dynamics and long‐term persistence of species. [ABSTRACT FROM AUTHOR]

Presents a response to a rebuttal of the author's criticism of a research paper by Hjältén and Price. Elements that could be included in a reply/opinion paper, including a defence of criticisms levied, a discussion of the general limitations of papers, or an extension of key concepts or ideas discussed; Summary of Hjältén and Price's rebuttal, which fell along those lines, and criticism of the rebuttal.

Polyploid organisms are common and can be found across the tree of life. A key question is to understand how and why these polyploid lineages become established and persist in populations, particularly since they are predicted to have a low probability of success. While the collection of papers in this special issue addresses broad questions on the evolutionary ecology of polyploids, ultimately, these studies also highlight the myriad ways that we are examining what drives the success of polyploid lineages. In this paper we consider where we've been and the challenges that we face, and then propose several directions that will allow us to continue to propel the field towards our ultimate goal of understanding the rules that govern the establishment and persistence of polyploid populations. We conclude that developing this rule set will require a combination of model systems for which we have detailed knowledge of the phylogenetic and population genetic history, expanding our perspective beyond plants to include greater taxonomic breadth, and conducting studies in ecologically relevant settings. Additionally, we argue that future research on the evolutionary ecology of polyploidy should focus on integrating theory and empirical research, providing mechanistic linkages between the effects of whole genome duplication and population demography, and build a predictive framework to understand how anthropogenic change will impact polyploid organisms. [ABSTRACT FROM AUTHOR]

The classical view of peer review is that it is our primary process for assessing and judging whether research results should be published in a scholarly journal. However, the increased pressure to publish and technological developments are transforming peer review such that it is becoming a system that judges where work is published rather than whether the research is publishable (a 'where rather than if ' process). Ecology is a field in which publication numbers puts a particular pressure on the review system. In this forum piece, I summarize the issues with the current publication system and discuss how technology is changing it, while suggesting solutions for important prior and ongoing issues with the peer review system. The view explored here is that technological developments (e.g. ease of creating journals, internet sites, storage, data generation, sharing of data and analytical code) will not eliminate peer review per se but will allow for a new set of parameters in which ethics and the optimal use of public funding will play a vital role in the evolution of the review process. [ABSTRACT FROM AUTHOR]

The exploration of mechanisms that enable species coexistence under competition for a sole limiting resource is widespread across ecology. Two examples of such facilitative processes are intraspecific competition and spatial self‐organisation. These processes determine the outcome of competitive dynamics in many resource‐limited patterned ecosystems, classical examples of which include dryland vegetation patterns, intertidal mussel beds and subalpine ribbon forests. Previous theoretical investigations have explained coexistence within patterned ecosystems by making strong assumptions on the differences between species (e.g. contrasting dispersal behaviours or different functional responses to resource availability). In this paper, I show that the interplay between the detrimental effects of intraspecific competition and the facilitative nature of self‐organisation forms a coexistence mechanism that does not rely on species‐specific assumptions and captures coexistence across a wide range of the environmental stress gradient. I use a theoretical model that captures the interactions of two generic consumer species with an explicitly modelled resource to show that coexistence relies on a balance between species' colonisation abilities and their local competitiveness, provided intraspecific competition is sufficiently strong. Crucially, the requirements on species' self‐limitation for coexistence to occur differ on opposite ends of the resource input spectrum. For low resource levels, coexistence is facilitated by strong intraspecific dynamics of the species superior in its colonisation abilities, but for larger volumes of resource input, strong intraspecific competition of the locally superior species enables coexistence. Results presented in this paper also highlight the importance of hysteresis in understanding tipping points, in particular extinction events. Finally, the theoretical framework provides insights into spatial species distributions within single patches, supporting verbal hypotheses on coexistence of herbaceous and woody species in dryland vegetation patterns and suggesting potential empirical tests in the context of other patterned ecosystems. [ABSTRACT FROM AUTHOR]

The most studied ecogeographic rule is Bergmann's rule, but aspects of the original paper are often presented incorrectly even though Bergmann (1847) is explicitly cited. The goal of this paper is to 1) summarize the contents of Bergmann's paper, supported by direct translations, and 2) to discuss the main issues surrounding Bergmann's rule based on Bergmann's intentions and early definitions of the rule. Although Bergmann himself never formulated an explicit rule, based on Bergmann's (1847) intentions and early definitions of Bergmann's rule, Bergmann's rule is: 'Within species and amongst closely related species of homeothermic animals a larger size is often achieved in colder climates than in warmer ones, which is linked to the temperature budget of these animals.' Bergmann (1847) assumed that the surface area of an animal is a measure for heat dissipation and an animal's volume a measure of its heat production. As body size increases, an animal's surface area increases less than its volume; however, modifications in morphology and behaviour will also influence the temperature budget. Bergmann hypothesized that when everything but size is equal, the smaller animals should live in warmer areas. This was supported by empirical data on > 300 bird species belonging to 86 genera. Recommendations for use of the term Bergmann's rule include 1) inclusion of a thermoregulatory mechanism, 2) application only to homoeothermic animals, 3) but to any taxonomic group, 4) tests of the rule should test the assumption that larger animals have to produce less heat to increase body temperatures, and 5) future authors should either go back to the original publication (Bergmann 1847) when referring to it or simply not cite it at all. [ABSTRACT FROM AUTHOR]

The acoustic complexity index (ACI) is a commonly used metric in ecoacoustics, demonstrating reliability across diverse environments and ecological conditions. However, this index requires specific procedures to be applied correctly. Based on the Canberra metric, the ACI is an unsupervised metric formulated to extract information from fast Fourier transform (FFT) sonic matrices. The ACI measures contiguous differences in acoustic energy of each frequency bin along temporal steps (ACItf) and a temporal interval along the frequency bins (ACIft). Aggregating data after an FFT with a clumping procedure allows for better scaling of sonic signals before computing the ACI. A filter must be applied to reduce the effects of nonenvironmental signals produced by microphone electrical noise . Due to the singularity of the index for values of 0, ACI requires ad hoc procedures to exclude element pairs for which one of the elements is equal to 0 from the comparisons. The spectral and temporal sonic signatures are vectors obtained from the sequence of ACItf and ACIft values, respectively. The comparison between sonic signatures using the chord distance index returns spectral and temporal sonic dissimilarities, allowing the evaluation of sonic patterns at different temporal and spatial resolutions. Sonic variability, sonic evenness, and the effective number of frequency bins are further derivative metrics that help interpret sonic heterogeneity by distinguishing the temporal and spatial heterogeneity of sonoscapes. Moreover, this paper proposes changing the terminology of ‘acoustic complexity index' to ‘sonic heterogeneity index.' [ABSTRACT FROM AUTHOR]

The spatial structure of a host population has a profound effect on the dynamics of infectious diseases. The basic reproduction number, a central quantity in the study of epidemic dynamics, is affected by host clustering as well as host density. Several authors have developed methods to quantify the basic reproduction number in a spatially structured host population. The methods used and the expressions derived are however difficult to apply to real life spatial host structures. In this paper we introduce an explicit expression for the basic reproduction number using the O‐ring statistic, developed in spatial statistics, that quantifies the host density as a function of the distance from a randomly selected host individual. The O‐ring statistic is frequently used in the study of the ecology of spatially structured plant populations, being a convenient summary of the properties of a landscape by way of a single function. The connection we develop between spatial statistics and epidemic dynamics can be used to study the effect of host spatial pattern on the basic reproduction number of infectious diseases. As well as showing how explicit expressions for the basic reproduction number can be derived for landscapes with standard structures, our expression for the basic reproduction number is tested against a simulation model. The model structure in our simulation is motivated by the spread of a plant disease epidemic, although it is applicable more broadly. The agreement between our analytic expression for the basic reproduction number and the corresponding numeric quantity extracted from simulations is close to perfect across a wide range of landscape structures and model parameterisations, and including cases in which more than one species of host is at risk of infection. [ABSTRACT FROM AUTHOR]

Nestmate recognition is a widespread phenomenon and evolutionary important trait in the social insects. Yet evidence accumulates that the responses to non‐nestmates varies more than previously thought. We present a simple frequency‐dependent cost‐benefit model of nestmate recognition to understand conditions that might or might not favor the evolution of nestmate recognition that is based on cuticular hydrocarbon (CHC) profiles. Costs accounted for are costs for 1) maintaining a functional recognition system and 2) keeping a CHC profile that may be sub‐optimal regarding other functionalities like desiccation control, whereas the benefit of recognition is the prevention of nest raiding by other colonies. Unsurprisingly, the model indicates that recognition systems only evolve if costs are sufficiently low and benefits sufficiently high. In addition, the model suggests that nestmate recognition is more likely to evolve if colony turnover is fast (colony life‐expectancy is low). Our model creates evolutionary cycles that are typically longest under parameter combinations that just allow the evolution of recognition systems at all; the system expresses attributes of a rock‐paper‐scissors game. The model shows that a breakdown of nestmate recognition may occur under changing ecological situations, e.g. as a result of reduced intraspecific competition or increased abiotic stress. We speculate that such effects may be involved in the formation of supercolonies during invasions. Nestmate recognition may have evolved more to prevent interspecific predation or parasitism by antagonists that managed to mimic their host's CHC profile than as a mechanism to prevent exploitation by conspecific colonies. [ABSTRACT FROM AUTHOR]

Publication and citation decisions in ecology are likely influenced by many factors, potentially including journal impact factors, direction and magnitude of reported effects, and year of publication. Dissemination bias exists when publication or citation of a study depends on any of these factors. We defined several dissemination biases and determined their prevalence across many sub-disciplines in ecology, then determined whether or not data quality also affected these biases. We identified dissemination biases in ecology by conducting a meta-analysis of citation trends for 3867 studies included in 52 meta-analyses. We correlated effect size, year of publication, impact factor and citation rate within each meta-analysis. In addition, we explored how data quality as defined in meta-analyses (sample size or variance) influenced each form of bias. We also explored how the direction of the predicted or observed effect, and the research field, influenced any biases. Year of publication did not influence citation rates. The first papers published in an area reported the strongest effects, and high impact factor journals published the most extreme effects. Effect size was more important than data quality for many publication and citation trends. Dissemination biases appear common in ecology, and although their magnitude was generally small many were associated with theory tenacity, evidenced as tendencies to cite papers that most strongly support our ideas. The consequences of this behavior are amplified by the fact that papers reporting strong effects were often of lower data quality than papers reporting much weaker effects. Furthermore, high impact factor journals published the strongest effects, generally in the absence of any correlation with data quality. Increasing awareness of the prevalence of theory tenacity, confirmation bias, and the inattention to data quality among ecologists is a first step towards reducing the impact of these biases on research in our field. [ABSTRACT FROM AUTHOR]

The scientific output of W. D. Hamilton can be broadly split into two parts; the first dealing with inclusive fitness and the evolution of social behaviour while the second part focused on the role of parasites in the evolution of sex. This change in research interest was marked by a classic paper published in this journal in 1980, 'Sex versus non-sex versus parasite'. To mark Hamilton's death I consider the historical background and influence of this paper. [ABSTRACT FROM AUTHOR]

Range expansion is the spatial spread of a population into previously unoccupied regions. Understanding range expansion is important for the study and successful management of ecosystems, with applications ranging from controlling bacterial biofilm formation in industrial and medical environments to large scale conservation programmes for species undergoing climate‐change induced habitat disruption. During range expansion, species typically encounter competitors. Moreover, the spatial environment into which expansion takes place is almost always heterogeneous. Nevertheless, the impact of competition and spatial landscape heterogeneities on range expansion remains understudied. In this paper we present a theoretical framework comprising two competing generic species undergoing range expansion and use it to investigate the impact of spatial landscape heterogeneities on range expansion with a particular focus on its effect on competition dynamics. We reveal that the area covered by range expansion is highly variable due to the landscape heterogeneities. Moreover, we report significant variability in competitive outcome (relative abundance of a focal species), but determine that this is induced by low initial population densities and is independent of landscape heterogeneities. We further show that both area covered by range expansion and competitive outcome can be accurately predicted by a Voronoi tessellation with respect to an appropriate metric, which only requires information on the spatial landscape and the response of each species to that landscape. Finally, we reveal that if species interact antagonistically during range expansion, the dominant mode of competition depends on the initial population density; antagonistic actions determine competitive outcome if the initial population density is high, but competition for space is the dominant mode of competition if the initial population density is low. These findings enhance our understanding of how competition for space and antagonistic interactions affect range expansion in spatially heterogeneous environments and provide a predictive tool for future species‐specific approaches. [ABSTRACT FROM AUTHOR]

The article discusses the significance of citing references in research works pertaining to ecology and the environment. According to the author, research works and such other papers about ecology the foundation of ecological science. The credibility of scientific work depends on its verifiable citations which functions to support the arguments presented in the paper. However, the author argues that there is no existing studies which explore the suitability or even fidelity of citations in ecological journals.

Populations and ecological communities are changing worldwide, and empirical studies exhibit a mixture of either declining or mixed trends. Confusion in global biodiversity trends thus remains, while assessing such changes is of major social, political, and scientific importance. Part of this variability may arise from the difficulty to reliably assess global biodiversity trends. Here, we conducted a literature review of studies documenting the temporal dynamics of global biodiversity. We classified the differences among approaches, data, and methodology used by the reviewed papers to reveal common findings and sources of discrepancies. We show that reviews and meta‐analyses, along with the use of global indicators, are more likely to conclude that trends are declining. On the other hand, the longer the data are available, the more nuanced are the trends they generate. Our results also highlight the lack of studies providing information on the impact of synergistic pressures on a global scale, making it even more difficult to understand the driving factors of the observed changes and how to decide conservation plan accordingly. Finally, we stress the importance of taking into account the sources of confusion identified, as well as the complexity of biodiversity changes, in order to implement effective conservation strategies. In particular, biodiversity dynamics are almost systematically assumed to be linear, while non‐linear trends are largely neglected. Clarifying the sources of confusion in global biodiversity trends should strengthen large‐scale biodiversity monitoring and conservation. [ABSTRACT FROM AUTHOR]

Bias, or any set of factors that influence the general expression of merit, is common in science and is an inevitable by-product of an imperfect but otherwise reasonably objective human pursuit to understand the world we inhabit. In this paper, we explore the conceptual significance of a relatively tractable form of bias, namely publication and dissemination bias. A specific definition is developed, a working model of classification for publication bias is proposed, and an assessment of what we can measure is described. Finally, we offer expectations for ecologists with respect to the significance of bias in the publication process within our discipline. We argue that without explicit consideration of both the qualitative and quantitative aspects of publication bias in ecology, we limit our capacity to fairly assess and best use the science that we as a community produce. [ABSTRACT FROM AUTHOR]

Tree diversity and species identity are known to play an important role in modulating forest productivity and its capacity to buffer the effects of climatic events. The FunDivEurope exploratory platform allowed us to analyse this modulating effect in a medium‐term time span, after an abrupt rise to a new stable level of the average summer temperature of ca 2°C, in Mediterranean forests in central Italy. This paper aims to answer the following questions: 1) did increasing temperature and drought events affect the growth of thermophilous deciduous forests? 2) Was this effect buffered in mixed stands compared to monocultures? 3) Did co‐occurring tree species with different ecological characteristics, from more mesophilous to more xerophilous, have different responses? In 2012 and 2017, wood cores were collected from 659 trees in 36 plots representative of thermophilous deciduous forests. The selected tree species were Castanea sativa, Ostrya carpinifolia, Quercus cerris, Quercus ilex and Quercus petraea. In the sampling plots, they were present in pure stands and mixtures from two to four species. After measuring annual rings on cores, chronologies of basal area increment were built, and inventory data were used to estimate tree growth. Results showed a strong reduction of growth, lasting at least 18 years, after the temperature rise. Tree diversity significantly reduced the growth drop after the sudden and stable rise in summer average temperature. Tree mixture effect on growth stability appeared to be dependent on the tree species present in the mixture. Temperature rise and associated drought events, even without changes in rainfall, are one of the main challenges that European forests will face in the current scenarios of climate change. Tree diversity can buffer the effects of climate change over periods of at least 15 years and should be considered in forest management plans. [ABSTRACT FROM AUTHOR]

Species-abundance distribution (SAD) is one of the most basic descriptions of an ecological community. Vigorous controversy surrounded SAD from the 1940s to 1960s, and has since persisted. Isao Motomura first published a notable paper in 1932 to describe findings on SAD, and to provide an empirical model; nevertheless, this work has often been overlooked or incorrectly cited, probably due to being published in Japanese. Here, we introduce the works of Motomura with an English translation of the paper, and the subsequent research history of SAD. We also introduce the work of Numata et al., another Japanese paper, which provided the biological explanation for Motomura's model of SAD, although it was rarely cited by subsequent studies. We summarize that Motomura was the first to fit a statistical model to observed SAD, and that Numata et al. attempted to explain the observed SAD via underlying biological mechanisms. [ABSTRACT FROM AUTHOR]

The most highly cited ecologists and environmental scientists provide both a benchmark and unique opportunity to consider the importance of research funding. Here, we use citation data and self-reported funding levels to assess the relative importance of various factors in shaping productivity and potential impact. The elite were senior Americans, well funded, with large labs. In contrast to Canadian NSERC grant holders (not in the top 1%), citations per paper did not increase with higher levels of funding within the ecological elite. We propose that this is good news for several reasons. It suggests that the publications generated by the top ecologists and environmental scientists are subject to limitations, that higher volume of publications is always important, and that increased funding to ecologists in general can shift our discipline to wider research networks. As expected, collaboration was identified as an important factor for the elite, and hopefully, this serves as a positive incentive to funding agencies since it increases the visibility of their research. [ABSTRACT FROM AUTHOR]

In general, ectoparasitoids attack concealed hosts in protected situations whereas endoparasitoids use both concealed and exposed hosts. The difference is assumed to be the consequence of ecological constraints; ectoparasitic larvae are vulnerable both to predation and to climatic factors such as rainfall, and, hence, require some structures to protect themselves. I hypothesized that such ecological constraints should act as a within-species selection pressure to female ectoparasitoids, and hence that females should recognize the degree of concealment of the host and prefer concealed over exposed hosts for oviposition. To test this hypothesis, I examined 1) whether host concealment could influence host acceptance by the ectoparasitoid wasp Agrothereutes lanceolatus and 2) whether host concealment could influence the fitness of the offspring. Female wasps recognized and attacked (probed) both cocooned and exposed host prepupae in equal proportions, but discriminated between them after ovipositor insertion, and preferred the former for oviposition and the latter for host-feeding. They also selected to oviposit on hosts concealed in paper tubes. Thus host concealment was important for host selection in A. lanceolatus . Offspring fitness (measured as survival and size) was much lower on exposed hosts than on cocooned and paper-concealed hosts, even under laboratory conditions. Thus, host concealment influenced the fitness of wasp offspring, and, hence, is a good indicator of host quality for female wasps. Adaptiveness of host selection and host-feeding in A. lanceolatus in relation to host concealment is discussed. [ABSTRACT FROM AUTHOR]

The goal of a truly synthetic, cross-systems ecology has been often lauded but rarely implemented. Here, our authors have embraced the challenge to achieve synthesis via a multi-paper dialogue and we hope this format will act as a springboard for new ecological ideas, experiments and theories. [ABSTRACT FROM AUTHOR]

Pollination sustains terrestrial food webs and agricultural systems and links the dynamics of interacting plant and pollinator species. Although environmental stochasticity is ubiquitous and can propagate through communities via species interactions in a way that increases extinction risk, it is unknown whether stochasticity affects species uniformly across pollination networks. In this paper, we introduce a stochastic dynamic model that makes novel use of the birth function, and apply it to pollination networks of increasing size. We start with two‐ and four‐species networks, in order to first illustrate the effects of stochasticity per se and then how those effects combine with specialization. We then describe the relationship between partner number and stochastic extinction risk in empirical networks with > 20 species. In the two‐species network, increasing the variance of the stochastic term of the model increased the size of the region in parameter space where extinctions occur. In networks with four or more species, specialists were more vulnerable to extinction than generalists over a broad range of variances. Extinction risk in networks with > 20 species declined nonlinearly with increasing mutualist partner number. Our results demonstrate the importance of including species interactions and stochasticity when using population‐dynamic models to compare species' extinction risk. While models that omit either of these factors are likely to underestimate extinction risk, they disproportionately underestimate the vulnerability of specialists. [ABSTRACT FROM AUTHOR]

Generalist predators whose primary prey undergoes cyclic fluctuations, will predate on alternate food sources when the abundance of their primary prey is low. In this paper we have developed a general model of a predator that switches predation between its primary prey and two alternative, competing, prey species. When the predators primary prey is at high abundance, predation of the alternate, competing, prey species is low, which provides periods of temporal refuge for the alternate prey from predation. When the inter‐specific interactions between the competing prey species lead to different dynamical outcomes in the presence and absence of predation, increasing the duration of the temporal refuge promotes dominance of a competitively superior species that is vulnerable to predation. The general theoretical framework was extended to consider a key case study system of pine marten predation on red and grey squirrels. In the absence of predation, grey squirrels out‐compete red squirrels but preferential predation by pine marten on grey squirrels can suppress grey squirrel density and allow red squirrel recovery. A temporal refuge for both squirrel species can arise due to prey switching by pine marten in years when field voles, their primary prey in the UK, are abundant. The duration of the temporal refuge, quantified as the relative length of the multi‐annual vole population cycle where vole density is above a population threshold, is a critical factor determining the persistence of red and grey squirrels. Our findings therefore provide insights for the conservation of the endangered red squirrel in the UK and the Republic of Ireland and more generally on the influence of the population dynamics of primary prey species in determining community composition. [ABSTRACT FROM AUTHOR]

Non-consumptive effects (NCEs) - changes in prey behavior or physiology in response to predator threat - are common and can be as strong as consumptive effects. However, our knowledge of NCEs in arthropod systems is lacking. Factors related to study organism and environment have the potential to influence the occurrence and magnitude of NCEs in arthropod systems. While factors such as coevolutionary history of natural enemies and their prey, predator cue, predator or prey feeding mode, and refuge availability have been theoretically and empirically examined, no trends have been proposed for arthropods. We compiled 62 studies, yielding 128 predator-prey interactions, which explicitly examined NCEs in experiments where arthropods were identified to species, using a previously published database of papers from 1990 to 2005 and a new database of papers published from 2006 to 2015. Using these data, we conducted a meta-analysis to explore the influence of organismal and environmental characteristics on the magnitude of predator NCEs. Our analysis addressed the following three questions. 1) Does predator-prey coevolution give rise to stronger NCEs than when predator and prey species did not coevolve? 2) What influence does habitat type and refuge availability have on NCEs? 3) How do predator characteristics (cue type, hunting mode and life stage) and prey characteristics (mobility, life stage, specialization, gregariousness and feeding mode) influence NCEs? We found that while NCEs were similar across most measured characteristics, NCEs on prey activity were significantly stronger when predator and prey shared an evolutionary history. Our results support growing evidence that NCEs have a negative effect on prey traits and that behavioral NCEs are stronger than physiological ones. Additional studies are needed to be confident in any emerging patterns, therefore we identify key gaps in the literature on NCEs in arthropod systems and discuss ideas for moving forward. [ABSTRACT FROM AUTHOR]

Predicting the effects of climate change on Earth's biota becomes even more challenging when acknowledging that most species have life cycles consisting of multiple stages, each of which may respond differently to extreme environmental conditions. There is currently no clear consensus regarding which stages are most susceptible to increasing environmental stress, or 'climate extremes'. We used a meta‐analytic approach to quantify variation in responses to environmental stress across multiple life stages of marine invertebrates. We identified 287 experiments in 29 papers which examined the lethal thresholds of multiple life stages (embryo, larva, juvenile and adult) of both holoplanktonic and meroplanktonic marine invertebrates subjected to the same experimental conditions of warming, acidification and hypoxia stress. Most studies considered short acute exposure to stressors. We calculated effect sizes (log response ratio) for each life stage (unpaired analysis) and the difference in effect sizes between stages of each species (paired analysis) included in each experiment. In the unpaired analysis, all significant responses were negative, indicating that warming, acidification and hypoxia tended to increase mortality. Furthermore, embryos, larvae and juveniles were more negatively affected by warming than adults. The paired analysis revealed that, when subjected to the same experimental conditions, younger life stages were more negatively affected by warming than older life stages, specifically among pairings of adults versus juveniles and larvae versus embryos. Although responses to warming are well documented, few studies of the effects of acidification and hypoxia met the criteria for inclusion in our analyses. Our results suggest that while most life stages will be negatively affected by climate change, younger stages of marine invertebrates are more sensitive to extreme heating events. [ABSTRACT FROM AUTHOR]

Biologists have long been fascinated by species’ borders, and with good reason. Understanding the ecological and evolutionary dynamics of species’ borders may prove to be the key that unlocks new understanding across a wide range of biological phenomena. After all, geographic range limits are a point of entry into understanding the ecological niche and threshold responses to environmental change. Elucidating patterns of gene flow to, and returning from, peripheral populations can provide important insights into the nature of adaptation, speciation and coevolution. Species’ borders form natural laboratories for the study of the spatial structure of species interactions. Comparative studies from the center to the margin of species’ ranges allow us to explore species’ demographic responses along gradients of increasing environmental stress. Range dynamics further permit investigation into invasion dynamics and represent bellweathers for a changing climate. This set of papers explores ecological and evolutionary dynamics of species’ borders from diverse empirical and theoretical perspectives. [ABSTRACT FROM AUTHOR]