Title Promoter Affiliations Abstract "Metals, oxidative stress and carotenoid-dependent coloration: does metal pollution fade the colour of great tits (Parus major)?" "Marcel Eens" "Behavioural Ecology & Ecophysiology" "The main focus of this project is to asses the signal value of carotenoid colouration in relation to oxidative stress levels and diet quality in the great tit (Parus major). The great tit has a carotenoid based signal, namely the yellow breast colour. The brightness of this colour is linked to the condition and the quality of the bearer. The research will be conducted in a well known metal pollution gradient. We expect that birds in polluted areas will fade under the influence of metal induced oxidative stress and/or lower food quality." "Metals, oxidative stress and carotenoid-dependent coloration: does metal pollution fade the colour of great tits (Parus major)?" "Marcel Eens" "Behavioural Ecology & Ecophysiology" "The main focus of this project is to asses the signal value of carotenoid colouration in relation to oxidative stress levels and diet quality in the great tit (Parus major). The great tit has a carotenoid based signal, namely the yellow breast colour. The brightness of this colour is linked to the condition and the quality of the bearer. The research will be conducted in a well known metal pollution gradient. We expect that birds in polluted areas will fade under the influence of metal induced oxidative stress and/or lower food quality." "Adaptive maternal investment in relation ot environmental variation in teh Great Tit (Parus major)" "Luc Lens" Biology "Through controlled field experiments in a population of the Great Tit (Parus major) residing in the proximity of the city of Ghent, (i) the effect of food availability and pathogeny of the environment on maternal investment in egg yolk immune factors and sex-allocation, and (ii) the consequences of differential maternal investment on the offspring's fitness will be examined." "Short and long term effects of light pollution on the great tit (Parus major) and the effectiveness of mitigating strategies." "Marcel Eens" "Behavioural Ecology & Ecophysiology" "Light pollution is likely to have a diverse and complex impact on individual animals. It can influence multiple biological systems simultaneously both directly and indirectly. The overall aim of this project is therefore to study the effects of light pollution andemerging mitigating strategies (part-night and adaptive lighting) on songbirds (great tits) in an integrated way." "Short and long term effects of light pollution on the great tit (Parus major) and the effectiveness of mitigating strategies." "Marcel Eens" "Behavioural Ecology & Ecophysiology" "Light pollution is likely to have a diverse and complex impact on individual animals. It can influence multiple biological systems simultaneously both directly and indirectly. The overall aim of this project is therefore to study the effects of light pollution andemerging mitigating strategies (part-night and adaptive lighting) on songbirds (great tits) in an integrated way." "An integrated study on the effects of long term exposure to artificial light at night in free-living great tits (Parus major) and on the effectiveness of mitigating strategies." "Marcel Eens" "Behavioural Ecology & Ecophysiology" "Artificial light at night (ALAN) or light pollution is an increasing and worldwide problem. There is growing concern that because of the disruption of natural light cycles, ALAN may pose serious risks for wildlife. While laboratory studies have shown that ALAN affects many aspects of animal behaviour and physiology, few studies have experimentally tested how free-living animals respond to ALAN. Furthermore, new lighting strategies are being used as these are considered to be ecologically friendly. However, the effects of ALAN are largely unexplored and even less is known about mitigating strategies. I will for the first time experimentally study, in an integrated way, the effects of long term exposure to ALAN in adult and developing free-living great tits, an important model species. Furthermore I will quantify the effectiveness of part-night lighting (e.g. lights off from midnight till 05:00) and low light intensities as potential mitigating strategies. In adults, I will study to what extent ALAN compromises the immune system. I will also examine the disruption of sleep by ALAN, and how this may affect food provisioning. Finally, I will study the effects of ALAN on early development and physiology of nestlings. At the end of this project, I aim to have a better understanding of the behavioural and physiological consequences of ALAN exposure in adult and developing animals and the effectiveness of emerging mitigating strategies." "The eco-evolutionary consequences of reward-based learning for behavioural variation." "Luc Lens" Biology "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 reward-based learning shape behavioural variation within populations within an ecological and evolutionary context. Next, the predicted eco-evolutionary 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." "Understanding species’ invasions: a mechanistic view on the invasion success of the common waxbill, a prolific avian invader." "Luc Lens" Biology "Invasive species are among the main global threats to biodiversity, economy and human well-being. Preventing their introduction is paramount but requires being able to reliably predict invasion risks. Currently, forecasts of where introduced species can invade strongly rely on extrapolating native-range realized niche characteristics onto new areas. Frequent mismatches between predicted and actual invasive occurrences however raise concern for the validity of such forecasts. Therefore, here, I will use the invasion of Iberia by common waxbills (Estrilda astrild) as a case study for examining the efficacy of alternative frameworks that aim to directly characterize species’ fundamental niches. By linking species’ behavioural, morphological and physiological traits with spatial environmental data, such ‘mechanistic’ approaches should be uniquely suited to delineate areas that are within a species’ fundamental environmental tolerance. Common waxbills constitute an interesting challenge, as they only show little overlap between native (i.e. sub-Saharan) and invasive range climate conditions. Functional traits data can readily be collected from museum specimens, captive populations and from the wild, as waxbills are the most widespread avian invader across Iberia. This project is among the first to apply a fully mechanistic framework to study the invasion of an endothermic vertebrate and will deliver new insights in the processes underlying biological invasions." "Mechanistic underpinnings of bird distribution ranges: temperature tolerance and energetic constraints" "Luc Lens" Biology "Global change is causing a redistribution of biodiversity worldwide. Humans continue to introduce species to areas far beyond their natural geographical ranges while changing climates force organisms to adapt, or to shift in location to stay within preferred environmental conditions. Understanding what underlies species’ geographical distributions is a longstanding question in ecology and evolution, given new impetus by the conservation challenges global change brings. Here, we use birds to test which fundamental mechanisms and processes that underly species’ capacity to sustain temperatures outside of their thermoneutral zones. Whereas most ecological forecasting currently relies on extrapolating realized niches, we will quantify species’ fundamental (thermal) niches to tackle the problem of how endothermic organisms balance the need to both generate and dissipate heat. By combining experimental studies on (sub)tropical birds introduced to Europe and on native European passerines that either migrate to the tropics or stay to overwinter in the north, we will elucidate what underlies bird species’ capacity for thermoregulation. By integrating this information with spatial environmental data under a single biophysical framework, we will leverage information on thermoregulation to generate, and evaluate, ‘mechanistic’ predictions of invasion success and range distributions.  This way, the project will foster the uptake of ecophysiological frameworks in predictive ecology." "A central role for the fungal quorum sensing molecule tryptophol during the early stages of a Batrachochytrium dendrobatidis infection?" "Frank Pasmans" "Department of Pathobiology, Pharmacology and Zoological Medicine" "Chytridiomycosis is a fungal skin disease that causes declines and extinctions in amphibians on a global scale. B. dendrobatidis is one of the infectious agents and although the negative impact of this pathogen on global diversity has been widely documented, the fundamentals of the hostpathogen interactions are still underexplored. The early interactions of B. dendrobatidis are described as attachment to (adhesion) and penetration in (invasion) amphibian skin. However, how these events occur and what factors are involved are unknown. We recently discovered a quorum sensing mechanism between B. dendrobatidis cells, through the secretion of tryptophol. This metabolite increases the adhesion capacities of B. dendrobatidis in vitro and it is produced during initial contact with a susceptible host. The production of tryptophol may thus play a role during the early infection stages and could interfere with the pathogen’s ability to colonize the host. We here study the role of tryptophol during the early infection steps of B. dendrobatidis. In a series of in vitro and ex vivo experiments, we will optimize a qualitative and quantitative method to examine the early pathogen-host interactions and we will examine to what extent tryptophol contributes to the invasion and adhesion capacities of the fungus. The insights gained in this project will help understanding fundamentals of the early host-pathogen interactions, which are necessary to open new opportunities for disease mitigation."