A major challenge in ecology is to understand the impact of increased environmental variability on populations and ecosystems. To maximize their fitness a variable environment, life history theory states that individuals should favor bet-hedging strategy, involving reduction annual breeding performance an increase adult survival so reproduction can be attempted over more years. As result, evolution toward longer span expected reduce deleterious effects extra population growth, consequently...

Abstract This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals attain maturity parr stage typically become freshwater resident. For individual fish, is not genetically fixed can be modified by previous growth energetic state in early life. phenotypic plasticity may influenced epigenetic modifications genome. Thus, survival determine...

Abstract A major challenge in understanding the response of populations to climate change is separate effects local drivers acting independently on specific populations, from global that impact multiple simultaneously and thereby synchronize their dynamics. We investigated environmental demographic mechanisms widespread decline marine survival rates Atlantic salmon ( Salmo salar ) over last four decades. developed a hierarchical Bayesian life cycle model quantify spatial synchrony 13 large...

1. It has been largely demonstrated that demographic performances of animals increase with age or experience as a result an improvement foraging skills, increasing reproductive effort selection process. However, little is known about the experience-related response populations to environmental variations. Theoretical studies consider age-related variations are greater under more restricting conditions, but this rarely tested. 2. We tested hypothesis on long-lived species, black browed...

1. Recent climate change has affected a wide range of species, but predicting population responses to projected using dynamics theory and models remains challenging, very few attempts have been made. The Southern Ocean sea surface temperature ice extent are warm shrink as concentrations atmospheric greenhouse gases increase, several top predator species by fluctuations in these oceanographic variables. 2. We compared the three seabird living sub-tropical, sub-Antarctic Antarctic biomes...

Abstract A hierarchical Bayesian life cycle model is presented that considers spatial covariation of marine history traits Atlantic salmon ( Salmo salar ) populations in the North Atlantic. The based on a collective analysis dynamics 13 stock units SU s) from two continental groups CSG America and Southern Europe single over period 1971–2014. sets up new assessment framework for stocks. It also provides to investigate drivers changes population including disentangling effects fisheries those...

Abstract Recent declines in Atlantic salmon Salmo salar populations are generally attributed to factors their marine life-phase. However, it is postulated that affecting freshwater life-phase might impact survival, such as the influence of body size. While larger smolts widely hypothesized have higher survival rates, empirical support remains scant, part due inadequate data and ambiguous statistical analyses. Here, we test smolt size on return a proxy for using 12-year dataset 3688 tagged...

1. There is growing evidence that ongoing climate change affects populations and species. Physiological limitation phenotypic plasticity suggest nonlinear response of vital rates to climatic parameters, the intensity environmental impact might be more pronounced while frequency extreme events increases. However, a poor understanding these patterns presently hampers our predictive capabilities. 2. A recent shift in Sahel, from droughty less severe condition, offers good opportunity test for...

Recent decline in abundance of Atlantic salmon (Salmo salar) and concomitant changes life history may result from a the growth conditions during marine migration. Available literature suggests existence sex-specific reaction norm linking maturation with environmental at sea. However, extent to which this mechanism explains variations age maturity remains unclear. Using historical collection scales (1987–2017) Sélune River, France, we showed that declined over first summer remained stable...

Pour réviser la gestion des populations de saumon en Bretagne, et plus particulièrement régulation leur exploitation par pêche à ligne rivière, l’OFB, INRAE l’Université Pau Pays l’Adour, collaboration avec Bretagne Grands Migrateurs, ont œuvré conjointement dans le cadre d’un vaste exercice d’aide décision (projet RENOSAUM, 2017-2022). Ce travail est sans précédent quantité données valorisées, prise compte recommandations internationales dialogue continu entre scientifiques acteurs qui...

Le projet SalmoGlob mené au sein de l’unité mixte recherche DECOD et du pôle MIAME, en partenariat avec le groupe travail sur saumon l’Atlantique Nord Conseil International pour l’Exploration la Mer (ICES/CIEM WGNAS), a significativement renforcé les bases scientifiques l'évaluation des stocks atlantique (Salmo salar) Nord. Un nouveau modèle été développé analyser dynamique populations l’ensemble vingt-cinq unités gestion (UG) trois complexes : sud-européen, nord-européen nord-américain. Il...

Les caméras acoustiques sont des sonars multifaisceaux à très haute fréquence permettent d'obtenir images de poissons sur lesquelles caractéristiques morphologiques et comportementales peuvent être extraites. L’utilisation ces outils en rivière permet une observation du comportement naturel sans structure porteuse, même eau turbide. Pour l’heure, l’analyse données passe par visualisation intégrale opérateurs, procédure fastidieuse coûteuse temps. Une automatisation traitement est donc...

En France, les poissons migrateurs amphihalins font l’objet d’une collecte de données le plus souvent décentralisée, généralement à l’échelle des comités gestion (COGEPOMI). Partant du constat qu’il n’existait pas document synthèse récent nationale sur l’état ces populations, Pôle MIAME a entamé depuis une dizaine d’années la réalisation synthèses bibliographiques. À l’heure actuelle, ciblées ont été rédigées pour lamproie marine, fluviatile, grande alose, l’alose feinte, saumon atlantique...

Abstract Dispersal is a key process in population and evolutionary ecology. Individual decisions are affected by fitness consequences of dispersal, but these difficult to measure wild populations. A long‐term dataset on geographically closed bird population, the M auritius kestrel, offers rare opportunity explore consequences. Females dispersed further when availability local breeding sites was limited, whereas male dispersal correlated with phenotypic traits. Female not lower they longer...

Pour mieux comprendre le déclin espèces amphihalines observées depuis plusieurs décennies et proposer des mesures de gestion adaptées, il est important pouvoir travailler sur les pressions qu’elles subissent pendant différentes phases leur cycle vie (en eau douce en mer). compléter sa riche collection séries historiques données scientifiques rivières index, pôle OFB-INRAE-Institut Agro-UPPA pour la Gestion migrateurs amphihalins dans environnement (pôle MIAME) a mis efforts particuliers...

Climate and human activities such as fisheries impact many animal species. However, the demographic processes through which population vital rates are affected, sensitivity of their growth rates, poorly understood. The Black-browed Albatross, Thalassarche melanophrys, is a long-lived threatened seabird Previous studies have shown that adult survival breeding success at Kerguelen affected by sea surface temperature anomalies (SSTA) during both nonbreeding season, tuna long-lining in Tasmanian...

Spatial patterns of site occupancy are commonly driven by habitat heterogeneity and thought to shape population dynamics through a site-dependent regulatory mechanism. When examining this, however, most studies have only focused on single vital rate (reproduction), little is known about how space effectively contributes the regulation dynamics. We investigated underlying mechanisms driving density-dependent processes in rates Mauritius kestrel where almost every individual was monitored....

Predicting the impact of human activities and their derivable consequences, such as global warming or direct wildlife mortality, is increasingly relevant in our changing world. Due to particular life history traits, long-lived migrants are amongst most endangered sensitive group animals these harming effects. Our ability identify quantify anthropogenic threats both breeding wintering grounds is, therefore, key importance field conservation biology. Using long-term capture-recapture data (34...

Avoidance of competition and inbreeding have been invoked as the major ultimate causes natal dispersal, but proximate factors such sex, body condition or birth date can also be important. Natal dispersal is expected to particular importance understanding ecological evolutionary implications strategies, since 1) numerous evidences suggest that individual differences in strategies are expressed early life (i.e. at onset movement), 2) more likely act during this stage 3) associated with highest...

Abstract Tropical cyclones are renowned for their destructive nature and an important feature of marine coastal tropical ecosystems. Over the last 40 years, intensity, frequency tracks have changed, partly in response to ocean warming, future predictions indicate that these trends likely continue with potential consequences human populations However, our understanding how currently affect biodiversity, pelagic species particular, is limited. For seabirds, impacts known be detrimental at...

Summary A high immediate mortality rate of released animals is an important cause translocation failure (‘release cost’). Post‐release dispersal (i.e. the movements from release site to first breeding site) has recently been identified as another source local failure. In spite their potential effects on conservation program outcomes, little known about quantitative these two sources and interactions with environmental factors management designs. Based long‐term monitoring data captive‐bred...

This study provides a regional picture of long-term changes in Atlantic salmon growth at the southern edge their distribution, using multi-population approach spanning 49 years and five populations. We provide empirical evidence life history being influenced by combination common signals marine environment population-specific signals. identified an abrupt decline from 1976 more recent after 2005. As these declines have also been recorded northern European populations, our significantly...