Coraline Bichet

French National Centre for Scientific Research | CNRS · Centre d'Etudes Biologiques de Chizé (CNRS & La Rochelle Université)

Mercury levels in the environment are increasing, such that they are also expected to accumulate in toppredators, but individual-based longitudinal studies required to investigate this are rare. Between 2017 and 2023, we therefore collected 1314 blood samples from 588 individual common terns (Sterna hirundo) to examine how total blood mercury conce...

In polygynous species, male reproductive success is often determined by their ability to dominate female harems. Harem‐holders sire a disproportionate number of offspring. Male dominance tends to correlate with age, but intense competition and early male mortality limit most males from achieving high social status. To maximize reproductive success...

Triazoles are among the most widely used fungicides in the world due to their efficacy against fungal crop diseases and their broad spectrum of action. Intensive use of triazoles has resulted in residual contamination in different compartments of agroecosystems and exposes non-target species to potential sublethal effects. Triazoles are known to be...

This study, conducted in western France from 2018 to 2021, aimed to examine the environmental disruption risks faced by the European Kingfisher, a species of conservation concern in Europe. We focused on examining the risks associated with habitat reduction, as well as the potential exposure of the species to trace elements and organic pollutants,...

In polygynous species, most dominant males sire a disproportionate number of offspring and dominance rank is assumed to be age dependent. Yet, extreme inter-male competition and high early male mortality prevent most males from reaching a social status that could guaranty a high reproductive success. Alternative reproductive tactics may have evolve...

The environmental presence of mercury has dramatically increased over the past century, leading to increased uptake, especially by top predators such as seabirds. Understanding the exact sources of contamination requires an individual-level approach, which is especially challenging for species that migrate. We took such an approach and located the...

Recent findings suggest that immune functions do not unidirectionally deteriorate with age but that a potentially adaptive remodeling, where functions of the immune system get downregulated while others get upregulated with age could also occur. Scarce in wild populations, longitudinal studies are yet necessary to properly understand the patterns a...

Haemoparasites represent a diverse group of vector-borne parasites that infect a wide range of vertebrate hosts. In birds, haemoparasite infection rates may be associated with various ecological and life history traits, including habitat choice, colony size and migration distance. Here, we molecularly assessed prevalence of three main haemoparasite...

Environmental salinization is recognized as a global threat affecting biodiversity, particularly in coastal ecosystems (affected by sea level rise and increased frequency and severity of storms), and the consequent osmoregulatory challenges can negatively affect wildlife. In order to assess whether coastal species can respond to changes in environm...

The quality of the environment individuals experience during development is commonly regarded as very influential on performance in later life. However, studies that have experimentally manipulated the early-life environment and subsequently measured individual performance in all components of fitness over the complete life course are scarce. In th...

Recent findings suggest that immune functions do not unidirectionally deteriorate with age but that a potentially adaptive remodelling where functions of the immune system get down regulated while others get upregulated with age could also occur. Scarce in wild populations, longitudinal studies are yet necessary to properly understand the patterns...

Background Understanding the evolution of migration requires knowledge of the patterns, sources, and consequences of variation in migratory behaviour, a need exacerbated by the fact that many migratory species show rapid population declines and require knowledge-based conservation measures. We therefore need detailed knowledge on the spatial and te...

Longitudinal studies of various vertebrate populations have demonstrated senescent declines in reproductive performance and survival probability to be almost ubiquitous. Longitudinal studies of potential underlying proximate mechanisms, however, are still scarce. Due to its critical function in the maintenance of health and viability, the immune sy...

Stress responses have evolved to quickly and appropriately deal with environmental stressors in order to secure or restore homeostasis. Since the regulation of stress hormones plays a key adaptive role, the regulatory processes controlling stress hormones levels may be under high selective pressure. The social environment during early life (parents...

Stress responses have evolved to quickly and appropriately deal with environmental stressors in order to secure or restore homeostasis. Since the regulation of stress hormones plays a key adaptive role, the regulatory processes controlling stress hormones levels may be under high selective pressure. The social environment during early life (parents...

Recent findings suggest that immunosenescence should not be considered as a unidirectional deterioration, and that the remodeling of the immune system with age could also be adaptive. Longitudinal studies on immunosenescence in wild populations are scarce, and therefore, processes like selective disappearance cannot be easily torn apart from senesc...

Telomeres are protective caps at the end of eukaryotic chromosomes that shorten with age and in response to stressful or resource‐demanding conditions. Their length predicts individual health and lifespan across a wide range of animals, but whether the observed positive association between telomere length and lifespan is environmentally induced, or...

In the last decade, house sparrow populations have shown a general decline, especially in cities. Avian malaria has been recently suggested as one of the potential causes of this decline, and its detrimental effects could be exacerbated in urban habitats. It was initially thought that avian malaria parasites would not have large negative effects on...

Geographic variation in acoustic signals has been investigated for five decades to better understand the evolution of communication. When receivers are able to discriminate among signals and to react accordingly, geographic variation can have major impacts on the ability of conspecifics to communicate. Surprisingly, geographic variation in alarm ca...

In the last decade, house sparrow populations have shown a general decline, especially in cities. Avian malaria has been recently suggested as one of the potential causes and its detrimental effects could be exacerbated in urban habitats. Due to their long co-evolution with their hosts, it was initially suggested that these parasites would have lim...

Telomeres are protective caps at the end of chromosomes, and their length is positively correlated with individual health and lifespan across taxa. Longitudinal studies have provided mixed results regarding the within-individual repeatability of telomere length. While some studies suggest telomere length to be highly dynamic and sensitive to resour...

The classical class I and class II molecules of the major histocompatibility complex (MHC) play crucial roles in immune responses to infectious pathogens and vaccines as well as being important for autoimmunity, allergy, cancer and reproduction. These classical MHC genes are the most polymorphic known, with roughly 10,000 alleles in humans. In chic...

To understand individual variation in physiology, ecologists have focussed on the roles of life-history trade-offs and environmental variation; however, longitudinal studies that span the lifetimes of animals are scarce. Such studies are especially important since trait expression is often affected by viability selection and ontogenetic processes,...

This poster gives an overview of the different methods we use in our common tern colony that has been the focus of a long-term individual-based study.

Selection is a central force underlying evolutionary change and a dynamic process that can vary in strength and direction, for example across time and space. The fitness consequences of individual genetic diversity have often been investigated by testing for multilocus heterozygosity‐fitness correlations (HFCs), but few studies have been able to as...

Variation in the strength of immune defences, both within and between individuals, likely influences resistance to parasites and pathogens. To understand this variation, ecologists have focussed on the roles of life-history trade-offs and environmental variation, but longitudinal studies that span the lifetimes of animals are exceedingly scarce. Su...

Some species responded successfully to prehistoric changes in climate [1,2], while others failed to adapt, and became extinct [3]. The factors that determine successful climate adaptation remain poorly understood. We constructed a reference genome and studied physiological adaptations in the Alpine marmot (Marmota marmota), a large ground-dwelling...

Supplemental Information for: Contrasting heterozygosity-fitness correlations across life in a long-lived seabird Appendix 1: Microsatellite characteristics and genotyping protocol Appendix 2: Year-by-year analyses regarding the effect of breeder heterozygosity on annual reproductive success Appendix 3: Model selection using an Information-t...

To reproduce, animals have to form pairs and large variations in the degree of mate switching are observed. Extrinsic and intrinsic factors can constrain individual's mate switching. Among intrinsic factors, genes involved in pair‐bonding, such as Avpr‐1a, receive increasing attention. The length of microsatellites present in the regulatory region...

The Alpine Marmot ( Marmota marmota ) is a rodent remnant of the ‘ice-age’ climate of the Pleistocene steppe, and since the disappearance of this habitat, persists in the high altitude Alpine meadow. Sequencing its genome, we reveal that the long-term cold-climate adaptation has altered its metabolism, in particular biosynthesis and storage of fatt...

Maintaining dominance status had long been considered to be less stressful than subordination. However, no consistency in stress levels of dominant and subordinate individuals has been demonstrated. Tactics used to achieve and maintain dominance could be determinant. In cooperatively breeding species, conflicts between dominants and subordinates ar...

Despite being identified an area that is poorly understood regarding the effects of climate change, behavioural responses to climate change are seldom explored. Climatic variability is likely to affect the frequency of extra-pair matings, a widespread alternative tactic to help prevent, correct or minimize the negative consequences of sub-optimal m...

Despite being identified an area that is poorly understood regarding the effects of climate change, behavioural responses to climatic variability are seldom explored. Climatic variability is likely to cause large inter-annual variation in the frequency of extra-pair litters produced, a widespread alternative mating tactic to help prevent, correct o...

Reintroductions inherently involve a small number of founders leading reintroduced populations to be prone to genetic drift and, consequently, to inbreeding depression. Assessing the origins as the genetic diversity and structure of reintroduced populations compared to native populations are thus crucial to foresee their future. Here, we aim to cla...

Small and isolated populations usually exhibit low levels of genetic variability, and thus, they are expected to have a lower capacity to adapt to changes in environmental conditions, such as exposure to pathogens and parasites. Comparing the genetic variability of selectively neutral versus functional loci allows one to assess the evolutionary his...

It is often proposed that females should select genetically dissimilar mates to maximize offspring genetic diversity and avoid inbreeding. Several recent studies have provided mixed evidence, however, and in some instances females seem to prefer genetically similar males. A preference for genetically similar mates can be adaptive if outbreeding dep...

Abstract In vertebrates, multiple host characteristics and environmental factors are known to influence infectious disease dynamics. Here, we investigated variability in prevalence and parasitemia of Plasmodium relictum in the house sparrow (Passer domesticus), across a large number of rural and urban populations (n = 16). We found that prevalence...

Host resources can drive the optimal parasite exploitation strategy by offering a good or a poor environment to pathogens. Hosts living in resource‐rich habitats might offer a favourable environment to developing parasites because they provide a wealth of resources. However, hosts living in resource‐rich habitats might afford a higher investment in...

Vector-borne diseases are particularly responsive to changing environmental conditions. Diurnal temperature variation has been identified as a particularly important factor for the development of malaria parasites within vectors. Here, we conducted a survey across France, screening populations of the house sparrow (Passer domesticus) for malaria (P...

Anthropogenic pollution poses a threat for the environment and wildlife. Trace metals (TMs) are known to have negative effects on haematological status, oxidative balance, and reproductive success in birds. These pollutants particularly increase in concentration in industrialized, urbanized and intensive agricultural areas. Pollutants can also inte...

Host-parasite interactions are one of the main topics in evolutionary sciences. This complex coevolution depends on several trade-offs and can be influenced by environmental factors. Here, we propose to study host-parasite interactions with a multi-level approach, using experimental and natural population studies, focusing on avian malaria parasite...

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Biodiversity is often defined as the number of different animal and plant species living in a given habitat. However, the persistence of a population often depends on the genetic variation among the individuals that compose the population. Genetic diversity is therefore an important component of biodiversity. Maintaining high levels of genetic dive...