Research Wendt Müller

Abstract

Early-life is one of the most critical periods for behavioural and cognitive development. An unfavourable early life environment with inadequate nourishment, deprived of social interactions and parental neglect/abuse may hence result in profound cognitive and behavioural deficiencies. How these effects can be interpreted in a framework of adaptive responses and how natural selection structures developmental effects arising from early life adversity remains unclear. Intriguingly, the parental traits that contribute to early life adversity might even be transmitted across generations ("cycle of violence"). Gaining a better understanding of the relative contribution of genetic and non-genetic factors in shaping such parental traits is therefore of fundamental relevance. This project investigates how an adverse early social environment has both short- and long-lasting effects on behaviour and cognition, whether these effects are of adaptive significance, and how epigenetic or other non-genetic effects contribute to their transgenerational transmission. This will be studied using a novel model system, the canary Serinus canaria, which allows to perform sophisticated cross-fostering experiments while manipulating the social context, namely sibling competition/aggression and parental abuse/neglect, two slightly contrasting early life adversities with possibly different evolutionary trajectories, in order to ultimately link early life experiences with individual life trajectories.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: García i Co Clara

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Most individuals encounter a social environment at birth, as they are born into a family. This social context has significant consequences for the offspring, as a disproportionate part of phenotypic organisation occurs early in life. Parents, and in particular mothers, have significant effects on the offspring's phenotypic organisation, as they are an essential part of the family, and via maternal effects, which allows mothers to adaptively shape the social phenotype of the offspring for the social environment later in life. However, this has rarely been studied, as the focus has mostly been on maladaptation, e.g. how maternal exposure to stressful social events impairs the development of social skills in offspring. Using the blue tit as study model my project aims to unveil the link between maternal anticipatory cues, offspring social phenotypes, and the adaptive value by investigating 1) how the maternal social environment triggers differential allocation of maternal cues; 2) whether maternal effects irreversibly shape the social behaviour of offspring; 3) how these effects are modulated by the (maternally programmed) expression of quality signals; 4) which fitness consequences arise from long-lasting maternal social programming and reciprocal effects. The outcome of my project expands the current state of knowledge as it provides novel information among others about the extent of individual variation in social performance and its consequences for group organisation.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: García Antón Alejandro

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Human population levels are continuously on the rise, and this is accompanied by unprecedented rates of urbanisation. The resulting levels of environmental change both directly and indirectly affect various ecosystem processes and cause steep biodiversity loss, making it a major concern in conservation biology. Yet given the inexorable rate of urbanisation we urgently have to discern cities as environments, which provide unique sets of opportunities and challenges for wildlife. Yet, animals that survive and thrive in cities have to deal with the spatio-temporal variability, novelty and complexity of urban landscapes, as well as with the altered pace of social life, as urban environments often sustain larger populations of the species dwelling in cities than more natural habitats. This likely poses specific social challenges, but also sets the conditions for the spread of socially transmitted diseases. Yet little is known about how disease transmission is actually affected by the heterogeneity of the urban landscape and how that is driven by individual variation in the capacities that animals require to live in urban environments. This project will, therefore, investigate which factors drive disease dynamics at the population-level in wild animals thriving in urban environments. Given that the transmission of the disease contains a significant individual component, this will be combined with detailed measures of among individual variation in social behaviour

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Leirs Herwig
• Fellow: Kiss Valentin Adrian

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Over the past decade, birds have proven to be excellent models to study maternal effects, in particular hormone-mediated maternal effects, where offspring phenotype is influenced by maternally derived hormones deposited in the yolk. But although the effects of yolk hormones have been studied in great detail, virtually nothing is known about how hormone-mediated maternal effects influence fitness. In order to achieve this, it is highly important to study the effects of yolk hormones on offspring phenotype in different environments. Maternal effects are thought to serve first of all as an adjustment to current environmental conditions, and females alter the amount of yolk hormones deposited in response to environmental changes - via phenotypic plasticity. However, maternal effects have not only an environmental but also a genetic component, and both of which shape the evolutionary significance of a maternal effect. At current, there is still (too) little information available on heritable variation in maternal traits generating changes in offspring phenotype through variation in egg components.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Despite the growing realization that cognition is likely to play an essential role in the adaptation to urban environments, and despite the increased appreciation of profound differences in behaviour among individuals, these aspects have thus far not been aligned. We currently lack a comprehensive, empirically supported and adequate understanding of how individual phenotypes interact with the urban environment, how that is driven by cognition, and what the ensuing consequences for ecological and evolutionary processes are. This requires (i) to gather accurate and repeatable measures on a variety of cognitive traits (e.g. exploration, (social) learning, social and spatial cognition etc…) in a sufficiently large sample size in the wild at the individual level (and in relation to different anthropogenic stressors); and (ii) to investigate the fitness and hence population-level consequences of such intraspecific variation in cognitive abilities.

Researcher(s)

• Promoter: Eens Marcel
• Co-promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

In recent years it has become clear that most animals have the ability to learn and that this often plays an important role in how individuals adjust their behaviours throughout their lives. Yet, how learning ultimately contributes to behavioural variation within populations is still poorly known. This project investigates the functioning and consequences of reward-based learning – a simple and universal mechanism by which individuals adapt their behaviour through reinforcement of successful actions – through an innovative combination of modelling, lab and field experiments. First, a theoretical framework is developed using an individual-based modelling approach to disentangle how interactions between environmental conditions, heritable behavioural traits and rewardbased learning shape behavioural variation within populations within an ecological and evolutionary context. Next, the predicted ecoevolutionary interactions are validated using lab experiments with Field Crickets (Gryllus campestris), a model organism in which reward-based learning is the dominant type of learning. Finally, the generality of the predicted patterns of behavioural variation for wild populations are tested by means of a field experiment with Great Tits (Parus major), a model organism with highly developed cognitive skills. As such, the project will provide important new insights into the role of non-genetic variation, as caused by reward-based learning, for ecological and evolutionary processes.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Baert Jan

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Animal populations often consist of foraging specialists and generalists, and this individual variation is increasingly recognized as a driving force behind eco-evolutionary dynamics. Foraging specialization is crucial for understanding population dynamics. However, neither the sources of individual variation in foraging strategies nor the fitness consequences thereof, are fully understood. The aim of this project is to investigate the ontogeny of consistent foraging strategies, i.e. when and how underlying behavioral and structural differences develop. Early life conditions can be crucial, as it is assumed that the environmental effects that occur during this period have long-term effects. Next, I will assess how intrinsic factors, such as competitiveness or consistent variation in other behavioural traits, determine how animals forage. Finally, I will assess whether foraging specialization has an impact on reproductive success, and how this depends on the environmental conditions. Since these objectives require a study of multiple life history stages, I will combine sophisticated early life experiments with GPS tracking during the juvenile and adult phases in a seabird (Lesser Black-headed Gull) that shows strong variation in foraging specialization. This project will significantly advance our understanding of the ecological and evolutionary implications of individual variation in foraging strategies, and how that makes individuals predisposed to environmental changes.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Morel Mélibée

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

In recent years, large-scale scientific initiatives have spurred the development of affordable lightweight tracking devices such that movement data are now collected in unprecedented quantities for a huge variety of species. Yet, appropriate tools to exploit the full potential of these tracking data are lagging behind. However, if we really want to capitalize on big movement data we must invest in an enhanced inference, particularly by combining heterogeneous and very high resolution data streams. And we have to pay attention to spatio-temporal patterns in the clustering sequences of movements or behaviours, which have almost virtually been ignored. To this end, a multidisciplinary consortium was established uniting leading experts in animal behaviour, moving object analysis, space-time or species-distribution modelling, spatio-temporal visualisation, and pattern recognition. By bridging disciplines within and across research areas, this multidisciplinary consortium has both the capacity to promote the development of analytical tools as well as to boost population and community ecology by building a new, integrated framework for the interpretation of state-of-the-art tracking data. We will follow a sequential approach by initially synthesizing how short-term behavioural responses and phenotypic adjustments within individuals, as well as consistent among-individual differences, impinge on movement ecological processes. This will set the stage for exploiting the full potential of tracking data, to understand behavioural responses, conspecific interactions and decision-making.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

A central tenet in evolutionary biology is that populations adapt to their environment with every generation through the process of natural selection. In long-lived species such as gulls (Larus spp.), environmental changes may however also occur at timescales much shorter than generations, which is the timeframe over which evolution acts. Individuals should therefore benefit from being able to (partly) adjust their physiology or behaviour to environmental changes throughout their lifetime. Such adjustments are nevertheless believed to be costly in terms of time or energy, and may thus jeopardize an organism's reproduction or survival. Individuals must therefore benefit when they are able to assess the reliability of environmental cues and the extent to which current adjustment costs may be offset by future benefits. Yet, current ecological theory generally assumes that individuals exhibit a constant degree of plasticity throughout their lifetime, tracking environmental changes to the best of their ability, irrespective of the entailed costs. In this project, I will elaborate further on this theory by assessing to what extent two co-occuring gull species adjust their foraging strategies throughout their lifetime in response to (a)biotic environmental cues, how such plasticity in foraging niche use may trade off with other life-history traits, and how individual differences in niche plasticity may therefore persist over evolutionary timescales.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Baert Jan

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Biparental care requires that two unrelated individuals raise their offspring together, which increases offspring survival and therefore parental fitness. However, each parent has to invest in care which comes with an individual cost and thus both parents aim to invest as little as possible. Recently, a parental strategy has been proposed that could provide a resolution for this conflict between the parents, that is taking turns in offspring provisioning, a form of cooperation that implies that parents alternate their feeding visits. However, some important aspects are still unknown, while vital for our understanding of the adaptive significance of this strategy. In particular, I aim to study (a) whether and how turn taking is an honest, evolutionary stable strategy; (b) how such a resolution of conflict between parents affects the parent-offspring conflict, as turn taking is thought to increase nest visit rates and thus offspring growth; (c) how turn taking can last, if parents may have to invest more heavily in another parental task besides provisioning; (d) how important compatibility between pair members is, and how such compatibility can be achieved; (e) and finally how the environmental conditions shape such parental strategy. To answer these questions, I will study a wild population of blue tits, a species with biparental care. I will use sophisticated tracking devices and cameras that allow detailed behavioural measurements, combined with well-designed experiments.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Iserbyt Arne
• Fellow: Griffioen Maaike

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Lesser black-backed gulls once successfully adapted to anthropogenic environments, indicating a high degree of behavioural plasticity. They are also considered to be generalist feeders with a wide ecological niche. But most individuals do not exploit the complete range of habitats and resources that are available, they rather specialize. However, the adaptive significance of such specialization likely depends on the predictability of the environment, which at current becomes increasingly unreliable - among others due to human-induced environmental changes. The PhD project aims at investigating how reproductive decisions vary with the ability of an individual to respond to environmental and anthropogenic changes, and how the costs and benefits of individual specialisation relate to trade-offs throughout the annual cycle (including migration, nest-site selection and reproduction). This will be studied in field experiments via large scale behavioural observations of individually marked (colour-ringed) birds in collaboration with the Research Institute for Nature and Forest (INBO). This will be combined with the implementation of state-of-the-art GPS tracking devices that collect detailed information about individual movements and behaviour 24h/24h via the high tech sensor network (LifeWatch Infrastructure) in collaboration with Flanders Marine Institute (VLIZ).

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project website

Project type(s)

• Research Project

Abstract

Parental care increases offspring survival, but comes at a cost for the parents. Parents are therefore presented with a trade-off between increased investment in current offspring and resource allocation into self-maintenance and future reproductive success. Thus to optimise their reproductive decisions, parents have to take numerous factors into account that relate to their own intrinsic capacity as well as to aspects of their social and ecological environment. With my research I aim to increase our understanding of (1) how reproductive decisions are related to environmental variation in food availability and food accessibility. In particular, I want to study whether and how individual specialisation in resource use constraints parents to comply their offspring's need; (2) how individual decisions depend on the partner, and how efficient withinpair coordination and equality in reproductive investment is achieved to ultimately maximise reproductive success; (3) how intrinsic changes, such as occur in the context of senescence, influence reproductive strategies - via changes in foraging performance and residual reproductive value. To answer these questions, I will study a wild population of individually marked Lesser black-backed gulls, a long-lived migratory seabird species with a high level of inter-individual variation in resource use. I will make use of state-of-the-art GPS devices that allow detailed measurements of parental effort and parental decision rules.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Kavelaars Marwa

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

To maximise survival and reproductive success, individuals are expected to optimise their foraging efficiency, which is influenced by several intrinsic (e.g., body condition) and extrinsic factors (e.g., fisheries discards and sea surface temperature). Additionally, many individuals have further optimised their foraging efficiency and became specialists, by using only a small niche of the broad spectrum. However, specialisation may limit the behavioural plasticity needed when conditions change. For central place foragers (CPF), who need to return to a specific location between feeding trips, the effects of environmental changes are likely to be more conspicuous. Therefore, I aim to determine the foraging efficiency of a CPF and measure how this foraging efficiency relates to among- and within-individual variation in foraging specialisation. I will investigate how foraging strategies change in function of intrinsic and extrinsic factors, and predict the effects of a changing environment on individual foraging efficiency. To accomplish this, I will perform aviary and field experiments with Lesser Black-backed Gulls, equipped with remote sensing devices that allow detailed measurements of movement dynamics. Data from these experiments will be assimilated with data on environmental conditions and resources, especially fisheries discards, to develop an individual-based foraging model that allows predicting the effects of rapid environmental change on foraging efficiency.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Heylen Brigitte

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Biparental care requires that two unrelated individuals raise their offspring together, which increases offspring survival and therefore parental fitness. However, each parent has to invest in care which comes with an individual cost and thus both parents aim to invest as little as possible. Recently, a parental strategy has been proposed that could provide a resolution for this conflict between the parents, that is taking turns in offspring provisioning, a form of cooperation that implies that parents alternate their feeding visits. However, some important aspects are still unknown, while vital for our understanding of the adaptive significance of this strategy. In particular, I aim to study (a) whether and how turn taking is an honest, evolutionary stable strategy; (b) how such a resolution of conflict between parents affects the parent-offspring conflict, as turn taking is thought to increase nest visit rates and thus offspring growth; (c) how turn taking can last, if parents may have to invest more heavily in another parental task besides provisioning; (d) how important compatibility between pair members is, and how such compatibility can be achieved; (e) and finally how the environmental conditions shape such parental strategy. To answer these questions, I will study a wild population of blue tits, a species with biparental care. I will use sophisticated tracking devices and cameras that allow detailed behavioural measurements, combined with well-designed experiments.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Iserbyt Arne
• Fellow: Griffioen Maaike

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Families in which two parents raise their offspring are currently no longer seen as a harmonious unit. They rather represent a battleground shaped by evolutionary conflicts of interest among its members that are not perfectly related. This is particularly true for parents. Although parents temporarily cooperate to enhance offspring survival, each parent can gain extra benefits by transferring the largest workload to the partner. Parents thus need to negotiate about their investment to reach optimal cooperation. However, it is currently unclear how such negotiation can contribute to evolutionary stable levels of care. This is largely due to a lack of empirical knowledge about (1) how the negotiation process develops throughout a reproductive event, (2) sex differences in the costs and benefits of negotiation and (3) potential physiological constraints on cooperation. The aim of this proposal is to fill and bridge these knowledge gaps via carefully designed experimental manipulations of parental exploitation opportunities, sexual conflict intensity and family structures. Meanwhile, I will include a proximate view to examine the extent to which hormone profiles constrain negotiated levels of care. Taken together, this proposed research will significantly increase our knowledge about the mechanisms that lead to conflict resolution and set the stage for the next generation of theoretical negotiation models explaining evolutionary stability of biparental care.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: Iserbyt Arne

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Parental care is a widespread phenomenon among the animal kingdom. It increases offspring survival, but entails fitness costs for the parents too. The resulting trade-off between investing in current offspring or in self-maintenance is a central tenet of life-history theory. But the costs and benefits of any parental decision will not be constant, but vary with multiple environmental factors. When adjusting their level of investment, parents therefore respond to cues from their ecological and social environment. Phenotypic plasticity, the ability of an individual to alter trait expression in function of the environment, plays logically a central role during parental care. However, the ability to respond may under some circumstances be confounded. Individuals may for example differ in their foraging specialization, which impinges on their flexibility in parenting via an interdependence of behavioral consistency across different traits ("personality"). Moreover, the optimal parental decision will not only depend on the individual itself, but also on (its response to) the contribution to care by its partner. Parental responsiveness during this reciprocal interplay is thus likely to affect the efficiency of cooperation within pairs, and ultimately reproductive success. The reciprocal interplay in the debate over care, however, makes the coadaptation of corresponding traits possible (via indirect genetic effects), as has been shown in the context of parent-offspring communication. Such coadaptation may in turn impose limitations on the expression and evolution of individual behavioral traits - representing another important component for our understanding of the evolutionary ecology and stability of parental care. This multidimensional complexity of parental care is fascinating and highly relevant, given the importance of parental care for the expression and development of ecologically important traits. It can best be studied by applying the recently developed behavioral reaction norm concept, which allows to partition phenotypic variance and to subsequently identify the adaptive significance of individual differences in (behavioral) variance components.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Breugelmans Lissa

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Parental care increases offspring survival, but comes at a cost for the parents. Parents are therefore presented with a trade-off between increased investment in current offspring and resource allocation into self-maintenance and future reproductive success. Thus to optimise their reproductive decisions, parents have to take numerous factors into account that relate to their own intrinsic capacity as well as to aspects of their social and ecological environment. With my research I aim to increase our understanding of (1) how reproductive decisions are related to environmental variation in food availability and food accessibility. In particular, I want to study whether and how individual specialisation in resource use constraints parents to comply their offspring's need; (2) how individual decisions depend on the partner, and how efficient withinpair coordination and equality in reproductive investment is achieved to ultimately maximise reproductive success; (3) how intrinsic changes, such as occur in the context of senescence, influence reproductive strategies - via changes in foraging performance and residual reproductive value. To answer these questions, I will study a wild population of individually marked Lesser black-backed gulls, a long-lived migratory seabird species with a high level of inter-individual variation in resource use. I will make use of state-of-the-art GPS devices that allow detailed measurements of parental effort and parental decision rules.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Kavelaars Marwa

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The aim of this project is to study condition-dependence of song and mate choice in canaries (Serinus canaria). So far, experimental studies have focussed on the effect of environmental quality in order to study condition dependence, in particular in the context of the 'developmental stress hypothesis'. The main focus of this study will be on (a) the effect of genetic condition on the expression of song and (b) the consequences of genetic quality for female mate choice.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: De Boer Raïssa

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Senescence, the progressive deterioration of performance with advancing age, is increasingly documented in natural animal populations. The main research focus has been on the age-related decline of physiological traits and components of reproductive success, the latter typically measured as the number of offspring raised to independence. However, offspring number is only one component of reproductive success while offspring quality may also change as a function of parental age. The existence of such phenotypic changes is inferred from parental-age effects on offspring recruitment and longevity. Thus variation in offspring phenotype with parental age has significant fitness consequences, but very little is known as to why offspring from older parents may have decreased survival prospects. In the proposed project we, therefore, shift the focus on transgenerational aspects of ageing to improve our understanding of the evolutionary ecology of senescence. We will study different pre- and postnatal pathways, to investigate how they may impinge on offspring development, whether these different mechanisms possibly counterbalance each other or to what extent they act in concert. To this end, we will combine sophisticated cross-fostering experiments in the field with cross-sectional, longitudinal and state-of-the-art behavioural tracking approaches. This project is only feasible as we can make use of a unique, long-term study population of individually marked Lesser black-backed gulls.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Interactions between caring parents and their offspring are one of the most widespread social behaviours in animals. These parent-offspring interactions involve two parties and its evolution is, therefore, dependent on the evolution of two traits, parental provisioning and offspring begging. From a quantitative genetic perspective both behaviours should co-adapt, which should ultimately lead to (genetic) co-variation. But evidence for co-adaptation, its underlying genetics and the potential fitness consequences is as yet very limited, especially in natural populations. To test predictions of the co-adaptation hypothesis I make use of wild blue tits (Cyanistes caeruleus)

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: Lucass Carsten

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The aim of this project is to study condition-dependence of song and mate choice in canaries (Serinus canaria). So far, experimental studies have focussed on the effect of environmental quality in order to study condition dependence, in particular in the context of the 'developmental stress hypothesis'. The main focus of this study will be on (a) the effect of genetic condition on the expression of song and (b) the consequences of genetic quality for female mate choice.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: De Boer Raïssa

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Begging, the solicitation of food from parents by as yet dependent offspring, forms a trait with direct and significant consequences on growth, survival, and thus ultimately on fitness. Obviously, begging for food from parents should elicit the transfer of resources, typically a greater amount than parents are selected to provide, since parents and offspring are, at least in birds, not genetically identical. When offspring seeks parental investment, their begging exerts a selective pressure on parental provisioning. But begging is at the same time also target of selection, because it is influenced by the parental response. Both behaviors should, therefore, ultimately become co-adapted. Being agent and target of selection, begging follows a complex evolutionary trajectory, which is additionally flavoured by the evolutionary conflict over parental investment. From this it becomes clear that it requires detailed information on both selection and inheritance of begging in order to understand its evolutionary potential. A very powerful quantitative genetic tool to study genetic mechanisms and evolutionary processes is to impose artificial selection upon the trait of interest, here begging. Artificial selection not only allows to identify the pattern of inheritance, but also to investigate genetic covariances and correlated responses in traits that generate trade-offs or that are co-adapted. This opens the possibility to test important evolutionary ecological predictions for instance in the context of evolutionary conflicts of interest and the honest signaling of offspring need. The use of artificial selection is also suitable to identify underlying control mechanisms via a correlated selection on physiological traits. Physiological mechanisms have the potential to affect or even constrain the response to selection by linking the expression of different traits and by generating trade-offs across contexts or life-history stages. Studying the phenotypic mechanisms such as the regulating role of testosterone is, therefore, necessary and will complement the research into the genetic mechanisms. Ultimately, the combined information will help to understand what mechanisms make begging adaptive and thus improve our understanding of the evolutionary ecology of life-history traits and fitness components.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Fresneau Nolwenn

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The evolution of parental care is central to our understanding of among other social systems and sexual selection, which are main areas of research in evolutionary biology. However, virtually nothing is known about its genetic architecture. Parental care includes complex parent-offspring interactions and its evolution therefore depends on the evolution of two traits, parental provisioning and offspring begging. Both behaviours should ultimately become genetically correlated, since changes in one trait exert a selective pressure on the evolution of the other. To complicate matters, the evolution of parental care is also shaped by a conflict of interest over the degree of provided parental investment between parents and offspring. My proposed research project aims at studying the genetic basis and consequences of co-adaptation between parental provisioning and offspring begging. In a first step, I will separately look at the heritability and phenotypic plasticity of both, parental provisioning and offspring begging, which set the basis for any co-evolutionary process. Next, I will focus on the co-variance of both traits using an intra-individual and an intra-family approach. Finally, I will study the functional consequences of co-adaptation for both parents and offspring, which will also improve our understanding of who is winning the parent-offspring conflict.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: Estramil Natalia

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Using a pedigreed captive canary population, the proposed project applies a quantitative genetic approach to the mechanisms and function of bird song, a trait playing an important role in the study of sexual selection. We will estimate the genetic inheritance of bird song as well as potential environmental influences. In order to test predictions of evolutionary theory in the context of sexual selection, we will investigate whether bird song indicates genetic and/or environmental quality, and analyze genetic correlations among song parameters, condition and immunocompetence. Finally, we apply a quantitative genetic approach to the endocrine regulation of corticosterone and testosterone, as the evolution of the traits studied here may depend on indirect selection on the underlying mechanisms.

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Over the past decade, birds have proven to be excellent models to study maternal effects, in particular hormone-mediated maternal effects, where offspring phenotype is influenced by maternally derived hormones deposited in the yolk. But although the effects of yolk hormones have been studied in great detail, virtually nothing is known about how hormone-mediated maternal effects influence fitness. In order to achieve this, it is highly important to study the effects of yolk hormones on offspring phenotype in different environments. Maternal effects are thought to serve first of all as an adjustment to current environmental conditions, and females alter the amount of yolk hormones deposited in response to environmental changes - via phenotypic plasticity. However, maternal effects have not only an environmental but also a genetic component, and both of which shape the evolutionary significance of a maternal effect. At current, there is still (too) little information available on heritable variation in maternal traits generating changes in offspring phenotype through variation in egg components.

Researcher(s)

• Promoter: Müller Wendt
• Fellow: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Interactions between caring parents and their offspring are one of the most widespread social behaviours in animals. These parent-offspring interactions involve two parties and its evolution is, therefore, dependent on the evolution of two traits, parental provisioning and offspring begging. From a quantitative genetic perspective both behaviours should co-adapt, which should ultimately lead to (genetic) co-variation. But evidence for co-adaptation, its underlying genetics and the potential fitness consequences is as yet very limited, especially in natural populations. Furthermore, co-adaptation is not the only process shaping the evolution of parental care. Its evolution is also affected by a conflict of interest over the amount of parental care, since offspring is selected to seek greater parental investment than the parents are selected to give. In my PhD-project I will integrate approaches from behavioural ecology and quantitative genetics to study: (a) the (genetic) correlation between offspring solicitation and parental provisioning genes in a natural population of blue tits (b) the potential fitness consequences of a disruption of this correlation for both parents - in the light of the sexual conflict over parental care (c) whether maternal effects play a role in shaping the co-evolution of offspring solicitation and parental provisioning."

Researcher(s)

• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Fellow: Lucass Carsten

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The evolution of parental care is central to our understanding of among other social systems and sexual selection, which are main areas of research in evolutionary biology. However, virtually nothing is known about its genetic architecture. Parental care includes complex parent-offspring interactions and its evolution therefore depends on the evolution of two traits, parental provisioning and offspring begging. Both behaviours should ultimately become genetically correlated, since changes in one trait exert a selective pressure on the evolution of the other. To complicate matters, the evolution of parental care is also shaped by a conflict of interest over the degree of provided parental investment between parents and offspring. My proposed research project aims at studying the genetic basis and consequences of co-adaptation between parental provisioning and offspring begging. In a first step, I will separately look at the heritability and phenotypic plasticity of both, parental provisioning and offspring begging, which set the basis for any co-evolutionary process. Next, I will focus on the co-variance of both traits using an intra-individual and an intra-family approach. Finally, I will study the functional consequences of co-adaptation for both parents and offspring, which will also improve our understanding of who is winning the parent-offspring conflict.

Researcher(s)

• Promoter: Eens Marcel
• Promoter: Müller Wendt
• Co-promoter: Eens Marcel
• Co-promoter: Müller Wendt
• Fellow: Estramil Natalia

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Eens Marcel
• Fellow: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The effects of maternal hormones in birds are thought to represent examples of so-called maternal effects and are thought to have evolved to translate the environmental conditions experienced by the mother into adaptive phenotypic variation of the offspring. Their adaptive significance is therefore likely to depend on the post-hatching conditions, but long-lasting changes in offspring phenotype need to be considered too.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Male ornaments are thought to indicate heritable male quality. Females selecting males with elaborated ornaments thereby select males that can afford to invest in their ornaments, e.g. because they are best adapted to the current conditions. Male ornaments have also been hypothesized to indicate the early developmental history of an individual. However, how females integrate the different types of information in mate choice is largely unknown.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The identification of the costs and benefits that shape the relationship between male attractiveness and maternal yolk androgen deposition is the aim of this project at the Department of Biology-Ethology of the University of Antwerp. These costs may be borne by the female (who may have to expose herself to high levels of androgens), the male (who are potentially deceived by the female since yolk androgen deposition could play an important role in the sexual conflict over parental care) or the offspring (who may be affected by costs of embryonic hormone exposure depending on its genetic quality). I will investigate proximate aspects of the maternal hormone deposition, look at the relationship between genetic and maternal effects, in particular through long-term studies, and address the question whether maternal yolk hormones mediate family conflicts.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

This project addresses the question whether the deposition of maternal yolk hormones in birds plays a critical role in the parental tug-of-war over the contribution to offspring care. Because offspring begging, which is at the heart of this family conflict, is influenced by maternal yolk hormones, it is to be expected that maternal hormones modulate this family conflict. Thus females may attempt to manipulate their partner through the transfer of hormones into the egg.

Researcher(s)

• Promoter: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Eens Marcel
• Fellow: Müller Wendt

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project