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Courtship displays, driven by sexual selection, are fascinating behaviors across a wide range of animal taxa. Birds, in particular, serve as excellent study models due to their often multimodal sexual exhibitions, which involve various sensory modalities such as coloration, body movements, and vocalizations. In this lecture, I will share insights from my research on Neotropical bird species. My work has focused on the mechanisms behind the production of these multimodal displays and their impact on female choice. I will explore key aspects such as intra- and interindividual variability in display performance, vigor, and skill, which have been central to my projects. I will specially discuss my studies on the Swallow-tailed Manakin, native to the Atlantic Forest and particularly notable for its cooperative cartwheel-like dance involving multiple males. I look forward to sharing these findings and discussing their implications for the study of animal behavior and evolutionary biology.

Developmental plasticity allows animal to adjust their phenotype to the current and future environment. In species with parental care, the presence and/or the quality of care can have pervasive effects on the offspring’s behavioural phenotype. However, the effects of early social experiences on the development of neurophysiological systems and the degree in which such effects can carry over to future generations are largely unknown. To fill this gap, we manipulated the early social environment of the cooperatively breeding fish Neolamprologus pulcher, where the offspring was raised: (i) with or without parents; (ii)  in small or large groups. We then investigated the long-effects of early social experience on the constitutive expression of genes belonging to the stress response system, dopaminergic system and to neuroplasticity within the social decision-making network (SDMN). We showed that early social experience has long-lasting effects on the expression of glucocorticoid receptor, expression of the dopaminergic receptor DRD1 and on the BDNF pathway within the SDMN. Additionally, I will show some of my ongoing work on the effects of paternal care on the development of the dopaminergic system in poison frogs.

It is a challenge to determine what is going on in another mind. This challenge is arguably greater when seeking information about the minds of nonverbal organisms. I will describe studies of metacognition, memory, and cognition in monkeys through which we strive to partly bridge this gap to other minds. The results of our work suggest that monkeys engage in limited introspection, regulate their cognitive process in service of short-term goals, and may form and manipulate mental images. Together with the work of many others, these findings give us a particular glimpse of what the primate brain architecture achieves without the benefit of language.

Natural environments usually experience moderate to high levels of spatial and temporal heterogeneity, which fosters the evolution of phenotypic plasticity. Organisms therefore need to assess the environment to modulate their phenotype accordingly. However, in complex environments, cues from different factors may elicit divergent or even antagonistic phenotypic responses. Amphibian larvae are exposed to variation in many environmental factors. We have studied their responses to three common axes of environmental variation: changes in light, risk of predation and risk of pond drying, using a combination of laboratory experiments, determination of physiological parameters and transcriptomics. Spadefoot toad tadpoles are capable of adjusting their pigmentation to improve background matching according to the  ambient albedo, with remarkable precision. Interestingly, they achieve such crypsis by decoupling the melanin synthesis pathway from its usual regulation by melanocyte stimulating hormone. We also find that spadefoot toad tadpoles increase their corticosterone secretion to accelerate their development in response to decreased water level, in contrast with their response to predators. In fact, we have found that the developmental responses to pond drying antagonize the activation of the typical antipredator inducible defenses. At a transcriptomic level, we observe that the two factors induce very different changes in gene expression in distinct organs or regions (brain, liver, tail), consistent with the relative importance of behavioural, physiological or morphological responses observed. We have further tested the consistency of these results comparing morphological, behavioural and metabolic responses to predators and to exogenous exposure to corticosterone (as would occur in response to pond drying) across nine anuran genera. The responses to predators are consistently opposite to those of increased corticosterone levels across phylogenetically distantly related species, evidencing the pervasiveness of such antagonistic responses. 

Tardigrades are microscopic animal phylum that are famously able to survive extreme stressful environments through cryptobiosis (i.e. a reversible ametabolic “hidden life”). In addition, they have remarkable, but understudied, diversity in reproductive biology, from reproductive mode to gamete diversity. My research bridges these two evolutionary aspects and asks whether (the variation in) cryptobiosis ability affects life history and reproductive biology. Using a combination of comparative and experimental approaches, I show how the adaptation to a common challenge of moss-dwelling taxa – anhydrobiosis in response to habitat desiccation – has sex-specific consequences in gamete function and mate choice. Ultimately, even the legendary water bear’s ecological “toughness” has evolutionary costs.

Animal social structure comes in a large variety of forms, reflecting the ways in which individuals associate and interact. Research increasingly shows how animal social structure, often conceptualised as a social network, fundamentally impacts ecological and evolutionary processes. Yet, we know comparably little about the underlying mechanisms shaping social structure in the first place. Here I will present work on the consequences of animal sociality on different population processes (e.g. reproduction and information transmission) in wild blue and great tits. Following, I will move on to theoretical and experimental work aiming at understanding the influence of different environmental features on the observed variation in social network structure.

Naked and Damaraland mole-rats are sometimes referred to as eusocial mammals but due to their subterranean lifestyle their social behaviour remains poorly understood. In this talk, I present and discuss our research on the social behaviour, ecology and physiology of these rodents and assess the extent to which Damaraland and naked mole-rats share similarities with social breeding systems in insects, birds and other mammals.

Citizen science encompasses various initiatives, yet differences in terminology, project goals, and cultural contexts often limit its effectiveness. Our study demonstrates how citizen science can support large-scale avian wildlife monitoring using a mobile app-based campaign (Muuttolintujen kevät), an automated bird sound classifier for Finnish birds. In 2023, 140,000 participants contributed nearly three million recordings, resulting in six million bird observations. We analyzed the spatial and temporal distribution of the data, user behavior, and the reliability of AI-based species identifications. To ensure data quality, raw audio is stored for ongoing validation. Citizen science may not only enhance public engagement and education, but also aid conservation efforts. Future expansions will incorporate advanced analytics to further support conservation strategies.

Seasonal life history transitions requires sensory pathways that detect and transduce environmental cues, and endogenously programmed timers. This presentation will focus on the endogenously programmed, circannual interval timer observed in Djungarian hamsters. These animals show robust phenotypic, physiological and behavioural responses to photoperiodic cues; short winter day lengths initiate a white pelage, adipose involution and a form of hibernation called torpor. After experiencing approximately 20 weeks of short photoperiods, all responses revert back to the long summer photoperiod phenotype, indicative of a circannual interval timer. Here I will describe how the brain controls the interval timing of hamster energy rheostasis and illustrate how deiodinase type-3, a transcript expressed in the tanycytes of the third ventricle in the hypothalamus are critical for establishing the period of circannual interval timing. Findings generated in Japanese quail will also be described in order to emphasize the potential for evolutionary conserved signaling of deiodinase type-3 for seasonal timing.

Lectin-carbohydrate interactions play a crucial role in numerous biological processes, including the immune response. An important class of lectins in the innate immune system is myeloid C-type lectin receptors (CLRs). Myeloid CLRs act as pattern recognition receptors and are mainly expressed by myeloid cells, such as macrophages, dendritic cells, and neutrophils. In innate immunity, CLRs contribute to self- and non-self discrimination. While the recognition of pathogen-associated molecular patterns (PAMPs) by CLRs may contribute to a protective immune response on the one hand, CLR engagement can also be exploited by pathogens for immune evasion on the other hand. Since various CLRs act as endocytic receptors and trigger distinct signaling pathways in myeloid cells, CLR targeting has proven useful for drug/antigen delivery into antigen-presenting cells and the modulation of immune responses.

The Lepenies group previously showed that myeloid CLRs are critically involved in immunity and affect the severity of infectious diseases and inflammatory processes. To identify novel CLR ligands with immune stimulatory or –modulatory properties, we have generated various CLR libraries in the format of so-called CLR-Fc fusion proteins. CLR-Fc fusion proteins consist of the extracellular domain of a respective CLR containing the carbohydrate-recognition domain, fused to the Fc fragment of human IgG1 molecules. Such libraries are not only available for mice and men, but have already been extended to large animals as well as mosquitos. The utility of CLR-Fc fusion proteins for the identification of novel CLR ligands has already been demonstrated, as we have contributed to the identification of CLR ligands from bacteria, viruses, parasites, and self-antigens. In proof-of-principle studies, the Lepenies group determined carbohydrate interactions with regard to specificity and affinity and assessed the utility of different carrier systems for CLR targeting and immune modulation.

The talk will cover recent discoveries of pathogen/CLR interactions and novel approaches for CLR targeting to modulate immune responses across species.

Stress can have positive and negative effects on an animal’s fitness and survival, and can be a consequence of its biotic or abiotic environment. Here I provide an overview of our field studies on the behavioural and physiological responses of small mammals to social and climatic challenges. My first case study investigates hormone concentrations of female striped mice, a facultatively social species. Our results showed hormonal differences between females following different social tactics. Interestingly, solitary females' corticosterone concentrations were lower than those of females that remained group living even before the solitary phenotype was expressed. For the second part of my talk, I describe our work investigating the effects of microclimate on hibernating species. Our results suggest that low ambient temperatures may not be the key determinant of hibernaculum selection in a dormouse species, although temperature is still likely to play an important role.