Temporal correlations among demographic parameters are ubiquitous but highly variable across species

Temporal correlations among demographic parameters can strongly influence population dynamics. Our empirical knowledge, however, is very limited regarding the direction and the magnitude of these correlations and how they vary among demographic parameters and species’ life histories. Here, we use long-term demographic data from 15 bird and mammal species with contrasting pace of life to quantify correlation patterns among five key demographic parameters: juvenile and adult survival, reproductive probability, reproductive success and productivity. Correlations among demographic parameters were ubiquitous, more frequently positive than negative, but strongly differed across species. Correlations did not markedly change along the slow-fast continuum of life histories, suggesting that they were more strongly driven by ecological than evolutionary factors. As positive temporal demographic correlations decrease the mean of the long-run population growth rate, the common practice of ignoring temporal correlations in population models could lead to the underestimation of extinction risks in most species

Fluctuating optimum and temporally variable selection on breeding date in birds and mammals

International audienceTemporal variation in natural selection is predicted to strongly impact the evolution and demography of natural populations, with consequences for the rate of adaptation, evolution of plasticity, and extinction risk. Most of the theory underlying these predictions assumes a moving optimum phenotype, with predictions expressed in terms of the temporal variance and autocorrelation of this optimum. However, empirical studies seldom estimate patterns of fluctuations of an optimum phenotype, precluding further progress in connecting theory with observations. To bridge this gap, we assess the evidence for temporal variation in selection on breeding date by modeling a fitness function with a fluctuating optimum, across 39 populations of 21 wild animals, one of the largest compilations of long-term datasets with individual measurements of trait and fitness components. We find compelling evidence for fluctuations in the fitness function, causing temporal variation in the magnitude, but not the direction of selection. However, fluctuations of the optimum phenotype need not directly translate into variation in selection gradients, because their impact can be buffered by partial tracking of the optimum by the mean phenotype. Analyzing individuals that reproduce in consecutive years, we find that plastic changes track movements of the optimum phenotype across years, especially in bird species, reducing temporal variation in directional selection. This suggests that phenological plasticity has evolved to cope with fluctuations in the optimum, despite their currently modest contribution to variation in selection

Temperature synchronizes temporal variation in laying dates across European hole-nesting passerines

Publisher Copyright: © 2022 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.Identifying the environmental drivers of variation in fitness-related traits is a central objective in ecology and evolutionary biology. Temporal fluctuations of these environmental drivers are often synchronized at large spatial scales. Yet, whether synchronous environmental conditions can generate spatial synchrony in fitness-related trait values (i.e., correlated temporal trait fluctuations across populations) is poorly understood. Using data from long-term monitored populations of blue tits (Cyanistes caeruleus, n = 31), great tits (Parus major, n = 35), and pied flycatchers (Ficedula hypoleuca, n = 20) across Europe, we assessed the influence of two local climatic variables (mean temperature and mean precipitation in February–May) on spatial synchrony in three fitness-related traits: laying date, clutch size, and fledgling number. We found a high degree of spatial synchrony in laying date but a lower degree in clutch size and fledgling number for each species. Temperature strongly influenced spatial synchrony in laying date for resident blue tits and great tits but not for migratory pied flycatchers. This is a relevant finding in the context of environmental impacts on populations because spatial synchrony in fitness-related trait values among populations may influence fluctuations in vital rates or population abundances. If environmentally induced spatial synchrony in fitness-related traits increases the spatial synchrony in vital rates or population abundances, this will ultimately increase the risk of extinction for populations and species. Assessing how environmental conditions influence spatiotemporal variation in trait values improves our mechanistic understanding of environmental impacts on populations.Peer reviewe

Démographie évolutive dans les populations exploitées : le cas du sanglier Sus scrofa

Le sanglier (Sus scrofa) est une espèce chassée emblématique en Europe. Comme la plupart des ongulés de zones tempérés, l'espèce sanglier s'est étendue en Europe au cours des dernières décennies. Le nombre de sangliers tués chaque année en France est passé de 36429 en 1973 à 526709 en 2011. Cette situation unique du sanglier parmi les ongulés est pourtant très commune en Europe, et a conduit à une augmentation du montant des indemnisations des dégâts occasionnés par le sanglier. Les indemnisations sont alors passées de 2 à 18 millions d'euros entre 1973 et 2001. Contrôler les populations de sangliers est donc devenu un objectif majeur pour les gestionnaires. Évaluer les paramètres démographiques qui pilotent les dynamiques de populations est nécessaire afin d'améliorer notre connaissance du sanglier. Mais s'intéresser à l'évolution des traits d'histoire de vie du sanglier est également indispensable pour mieux comprendre cette espèce. Par conséquent, contrôler les populations de sangliers en intégrant des considérations évolutives est essentiel pour permettre une gestion durable de cette espèce. Le temps est donc venu de mieux comprendre cette espèce dans un contexte de démographie évolutive, grâce à un suivi à long-terme unique d'une population de sangliers fortement chassée dans la forêt de Châteauvillain-Arc-en-barrois, France. Tout d'abord, d'un point de vue démographique, nous proposons un outil de gestion afin de contrôler le taux de croissance des populations de sangliers. Ensuite, nous replaçons le sanglier au sein des mammifères en nous intéressant plus particulièrement à des comparaisons inter spécifiques de tactiques d'histoire de vie, grâce à de récents développements méthodologiques en dynamique de population. Nous trouvons alors que le sanglier présente une stratégie d'histoire de vie plus proche de celle de petits mammifères (comme l'écureuil) que de celle d'un ongulé de taille similaire. Puis, nous trouvons que, en réponse aux variations de disponibilité alimentaire, les femelles sangliers présentent différentes stratégies de reproduction afin de maximiser le nombre de petits viablesWild boar (Sus scrofa) is an emblematic game species in Europe. As most ungulate populations in temperate areas, wild boar abundance and distribution has increased in most European countries over the last decades. The number of wild boar shot annually in France has increased from 36,429 in 1973 to 526,709 in 2011. This unique situation is common throughout Europe and has led to higher costs to agriculture because of damage to crops. Compensation for damage caused by wild boar in France rose from 2 to 18 million Euros between 1973 and 2001, a nearly tenfold increase. Controlling wild boar populations has thus become an important target for managers. Evaluating the vital rates that drive the population dynamics is necessary to improve our understanding of wild boar. But investigating the evolution of life history traits in wild boar is also required to improve our understanding of this species. As a consequence, controlling wild boar populations incorporating evolutionary considerations is essential to allow a sustainable management of this species. The time has thus come to better understand this species is an evolutionary demography context, taking advantage of a unique long-term monitoring of a heavily hunted wild boar population located in the Châteauvillain-Arc-en-barrois forest, France. First, from a demographic viewpoint, we provide a management tool to control population growth rate of wild boar population. Second, we put back the wild boar among mammals by focusing on inter-specific comparisons of life history tactics among mammals using recent developments in population dynamics. We found that wild boar exhibits a life history strategy close to small mammals such as squirrel rather than the life history strategy observed in similar-sized ungulates. Then, we found that, in response to changes in food availability, wild boar females are able to display different reproductive tactics to maximize the number of recruits at a given breeding even

Late-life costs of raising sons in bighorn sheep

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Demographic Methods Across the Tree of Life

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Biodemography: Unifying Concepts from Biology, Demography, and Mathematics

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Reproductive costs in terrestrial male vertebrates: insights from bird studies

International audienceReproduction requires resources that cannot be allocated to other functions resulting in direct reproductive costs (i.e. trade-offs between current reproduction and subsequent survival/reproduction). In wild vertebrates, direct reproductive costs have been widely described in females, but their occurrence in males remains to be explored. To fill this gap, we gathered 53 studies on 48 species testing direct reproductive costs in male vertebrates. We found a trade-off between current reproduction and subsequent performances in 29% of the species and in every clade. As 73% of the studied species are birds, we focused on that clade to investigate whether such trade-offs are associated with (i) levels of paternal care, (ii) polygyny or (iii) pace of life. More precisely for this third question, it is expected that fast species (i.e. short lifespan, early maturity, high fecundity) pay a cost in terms of survival, whereas slow species (with opposite characteristics) do so in terms of fecundity. Our findings tend to support this hypothesis. Finally, we pointed out the potential confounding effects that should be accounted for when investigating reproductive costs in males and strongly encourage the investigation of such costs in more clades to understand to what extent our results are relevant for other vertebrates

Meeting the challenges of wild boar hunting in a modern society: The case of France

International audienceModern hunting is an ambivalent practice, torn between leisure and labor. Nowhere are these conflicting dimensions better manifested than for wild boar-a simultaneous game and pest species in many countries. Here, we consider the sociological, political and cultural phenomenon of wild boar hunting from a change perspective, starting at its historical roots to future implications concerning the changing demographics, drivers, needs and practices of a modernizing hunting community. Using the case context of France, we present an approach to deconstructing each component of wild boar hunting firstly, and subsequently the external forces that change the nature of hunting. The objective of this manuscript is to discuss of the wild boar optimal harvesting to be applied in changing social and ecological environment. Findings show that the challenges facing wild boar management will likely intensify in the future, especially under the spotlight of a controversial public debate

Meeting the challenges of wild boar hunting in a modern society: The case of France

Modern hunting is an ambivalent practice, torn between leisure and labor. Nowhere are these conflicting dimensions better manifested than for wild boar—a simultaneous game and pest species in many countries. Here, we consider the sociological, political and cultural phenomenon of wild boar hunting from a change perspective, starting at its historical roots to future implications concerning the changing demographics, drivers, needs and practices of a modernizing hunting community. Using the case context of France, we present an approach to deconstructing each component of wild boar hunting firstly, and subsequently the external forces that change the nature of hunting. The objective of this manuscript is to discuss of the wild boar optimal harvesting to be applied in changing social and ecological environment. Findings show that the challenges facing wild boar management will likely intensify in the future, especially under the spotlight of a controversial public debate