Events at the MPIAB

Cognitive phenotypes of animals are shaped by the challenges they face throughout their lives and across evolutionary time. However, much cognitive research has focused on captive animals, largely divorcing them from these challenges. In this talk, I will present two lines of research investigating cognitive abilities in wild Malagasy primates. First, I will address the question of whether competent individuals become more valuable social partners by presenting results of a social learning experiment combined with behavioral observations of social interactions in group-living redfronted lemurs (Eulemur rufifrons). Second, I will present the results of our research on gray mouse lemurs (Microcebus murinus), where we investigated differences in cognitive performance between a captive and a wild population, showing that wild mouse lemurs performed better in some tests than captive ones. In addition, I will present a study on the link between cognition and fitness in wild mouse lemurs showing that cognitive performance and personality predict survival, highlighting the importance to study also cognition in the wild. [more]

Across taxa, social groups compete for territories and the resources they provide, engaging in interactions that pose significant fitness risks. Yet, the outcomes of intergroup conflicts are not fixed; individuals can mitigate these risks through within-group cooperation, allowing groups to gain the benefits of conflict while minimizing associated costs. As such, intergroup conflict is considered as a strong selective pressure, shaping the social dynamics, cooperation, and cognition of social species. Despite its significance, the evolutionary role of intergroup conflict in influencing social and cooperative attitudes is rarely examined, limiting our understanding of these processes. Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), as a pair, offer a unique opportunity to explore this question. These two closely related species share similar history trajectories, social environments, and cognitive capacities, but have also diverged in distinct ways. Chimpanzees live in a male-dominated society characterized by hostility towards out-groups, whereas bonobo are known for their high female-status society and relatively tolerant intergroup interactions. In this talk, I will examine how these contrasting behaviors in our closest living relatives provide insights into the evolution of social strategies and the role of intergroup interactions in shaping their societies. By leveraging and evaluating the similarities and differences between them, I will explore how in-group/out-group identities and pairwise versus collective cooperation manifest in the two species, and their potential link to hostile or peaceful out-group attitudes. I will evaluate the conditions and mechanisms underlying violence and cooperation, focusing on the importance of differentiated social relationships and bonds in guiding cooperative exchanges. [more]

Geographic differences in vocalisations provide strong evidence for animal culture, with patterns likely arising from generations of social learning and transmission. The current knowledge on the evolution of vocal variation has predominantly focused on fixed repertoire, territorial song in passerine birds. The study of vocal communication in open-ended learners and in contexts where vocalisations serve other functions is therefore necessary for a more comprehensive understanding of vocal dialect evolution. Parrots are open-ended vocal production learners that use vocalisations for social contact and coordination. Geographic variation in parrot vocalisations typically take the form of either distinct regional variations known as dialects or graded variation based on geographic distance known as clinal variation. In this study, we recorded monk parakeets (Myiopsitta monachus) across multiple spatial scales (i.e. parks and cities) in their European invasive range. We then compared calls using a multi-level Bayesian model and sensitivity analysis, with this novel approach allowing us to explicitly compare vocalisations at multiple spatial scales. We found support for founder effects and/or cultural drift at the city level, consistent with passive cultural processes leading to large-scale dialect differences. We did not find a strong signal for dialect or clinal differences between parks within cities, suggesting that birds did not actively converge on a group level signal, as expected under the group-membership hypothesis. We demonstrate the robustness of our findings and offer an explanation that unifies the results of prior monk parakeet vocalization studies. [more]

Through my PhD, I investigated a remarkable phenomenon of brain plasticity in the common shrew, focusing on how its brain adapts structurally and functionally to seasonal changes. The common shrew undergoes what is known as Dehnel’s phenomenon, a seasonal adaptation where brain and body sizes decrease significantly in winter before regrowing in spring. This adaptation likely serves to reduce metabolic demands when food resources are scarce, allowing the shrew to maintain essential physiological functions while conserving energy. Our findings reveal that from summer to winter, the common shrew undergoes an adaptive reduction in brain cell size, not through cell loss but through decreased cell volume. This microstructural change, marked by a decrease in intracellular water and an increase in extracellular water, might enable the brain to conserve energy when resources are scarce, making it more metabolically efficient during challenging winter conditions. I further explored how associative learning and activity levels differ between captive and wild shrews across seasons. In summer, wild-caught shrews demonstrate stronger associative learning abilities, but winter seems to slow cognitive processing. Additionally, activity levels vary with both season and captivity status, indicating that environmental factors strongly influence behavior. Lastly, i discovered that despite a reduction in overall brain volume, shrews retain essential spatial navigation skills in winter, prioritizing survival-related functions such as environmental navigation. By linking structural changes in the brain to functional outcomes, these studies demonstrate how shrews optimize cognitive abilities to adapt to seasonal environmental challenges. This work advances our understanding of brain plasticity and highlights the delicate balance between brain structure, energy efficiency, and cognitive functionality. It underscores how animals adapt their brains for immediate survival and the diverse challenges posed by their environments across different seasons. [more]

I will describe observational and experimental studies focusing on social network dynamics in the rock hyrax and spotted hyena, as well as simple models of the dynamics of social networks. These studies highlight sociality at different scales, from seconds to years, and demonstrate the flexibility of social animals and the many factors that are at play. I will show that social dynamics may result from individuals' efforts to maintain social homeostasis. The effect of social associations on microbial strain transmission will be illustrated. [more]

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The emerging field of movement ecology, facilitated by recent advances in biologging technology, provides a powerful framework for studying animal behavior and inferring ecological patterns. Yet, the characteristically short time-series data from biologgers limits our ability to understand how movement patterns are linked to long-term processes like climate and demographic change. Long-term field sites hold valuable longitudinal data on animal movements, including handheld-GPS locations and historical records from field notes and hand-drawn maps. These data are often archived and underused due to justifiable doubt over their utility in modern analytical frameworks. Nonetheless, they offer a remarkable opportunity to expand the temporal scope of movement ecology into the past and address pressing questions about animal movement in a rapidly changing world. In my PhD research, I explore the social and environmental factors shaping the movement ecology of white-faced capuchins (Cebus imitator), using three decades of movement data from 13 social groups at the Lomas Barbudal Monkey Project in Costa Rica. In chapter 1 and chapter 2, I introduce new methodological frameworks for validating and accurately interpreting non-collar movement data relevant to many longitudinal studies. I then demonstrate the insights these data can offer in chapter 3, revealing how longterm movement data can shed light on longstanding ecological theories and the effects of relatively rare but ecologically significant events, such as El Niño and immigration. Lastly, in chapter 4, I examine how group size, neighboring group sizes, and seasonality interact to influence the dynamics of competition, space partitioning, and daily movement patterns of capuchins. In my General Discussion, I outline future directions for long-term movement research, including new approaches to accelerating historical translations using machine learning and developing mechanistic models to enhance our understanding of the cultural inheritance of spatial information. Despite the crucial role of longitudinal studies in uncovering long-term ecological phenomena, interest and funding for such research are noticeably declining, jeopardizing the preservation of these valuable datasets. In an era dominated by cutting-edge technologies producing state-of-the-art animal movement data, unconventional data sources from longitudinal studies risk being overlooked and lost to time. To counter this, I introduce methodologies to validate and revive these data, supporting long-term animal movement projects across various systems and taxa. My thesis highlights the essential role of longitudinal movement data in revealing ecological insights that might otherwise remain hidden, advocating for a broader, long-term perspective in movement ecology. [more]

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Guinea baboons live in a multi-level society with units comprising one reproductively active “primary” male and a number of females and their young. Females show high leverage in mate choice and may freely transfer between different males. I will present a series of studies that examined female choices, using long-term data and the outcomes of field experiments from our CRP Simenti project in Senegal. Reproductive skew among males is low and male rank confers only a small reproductive advantage. Females do not exhibit preferences for males that have many friends, but aggressively monopolize males whose foraging abilities are experimentally enhanced. Overall, the key determinant of male reproductive success appears to be male longevity. I will discuss the variation in the determinants of male reproductive success in different baboon species against the background of the striking variation in their social systems and their phylogenetic history. [more]

Human-wildlife interactions are fundamentally driven by both societal and ecological factors, and negative interactions (i.e., "conflicts") are often underpinned by environmental injustices. Integrating local community perspectives and histories with data on ecology and animal behavior can help us to understand how people and wildlife can successfully share landscapes in a world of increasing climate change and human-wildlife overlap. In this talk, we will discuss case studies on human-carnivore interactions and wildlife movement in Nakuru, Kenya and California, USA, and explore how our own intersectional lenses can complement applied science to achieve better, more just conservation outcomes. [more]

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Understanding the genetics of bird migration is a long-standing goal in evolutionary biology. Blackcaps Sylvia atricapilla are ideal for this work as different populations exhibit enormous difference in migratory behaviour and little else. We characterize (i) phenotype, population structure and demographic history the blackcap, and (ii) identify sequence variants and signaling pathways that are associated with variation of the migratory phenotype. My talk will cover insight from classical studies on selection and cross-breeding experiments, ring recovery data, tracking approaches in the wild, to finally introducing novel insight from using a de novo assembled genome of the blackcap as reference for large scale demographic study with different phenotypes across their breeding range. [more]