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Info DEE # 34 - December 2021
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A WARM WELCOME TO OUR NEW COLLEAGUES
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Mr Marc Bastardot has returned to the DEE joining the group of Prof. Schwander as Field Assistant. Marc is located in office 2101, phone 41.76. Marc.Bastardot@unil.ch
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Mr Tadeas Priklopil has returned to the DEE joining the group of Prof. Lehmann as a Post Doctoral Researcher. Tadeas is located in office 4304. phone 42.79. Tadeas.Priklopil@unil.ch
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Hugo Darras (Group Keller) is the winner of the 2021 Prix Jeune Chercheur-euse awarded by the International Union for the Study of Social Insects (French section). He was awarded the prize for his work on the reproductive mechanisms of ants. Congratulations Hugo!
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Erica Van de Waal has been on an RTS radio show, meeting communications engineer, storyteller and co-founder of "Raconte!" Mélanie Gordon for the first time.
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We are please to announce that Claus Wedekind has been appointed for a second mandate as member for the FBM Prize Selection Committee until 2023.
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Laurent Keller and colleagues from universities in China and the United States, have published a paper in the Journal of Chemical Ecology entitled Characterization of Queen Supergene Pheromone in the Red Imported Fire Ant Using Worker Discrimination Assays.
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Abstract: Ants use chemical signals to communicate for various purposes related to colony function. Social organization in the red imported fire ant, Solenopsis invicta, is determined by the Sb supergene, with colonies of the monogyne (single-queen) form lacking the element and colonies of the polygyne (multiple-queen) form possessing it. Polygyne workers accept new reproductive queens in their nest, but only those carrying Sb; young winged queens lacking this genetic element are executed as they mature sexually in their natal nest or as they attempt to enter a foreign nest to initiate reproduction after mating and shedding their wings. It has been suggested that queen supergene genotype status is signaled to workers by unsaturated cuticular hydrocarbons, while queen reproductive status is signaled by piperidines (venom alkaloids). We used high-throughput behavioral assays to study worker acceptance of paper dummies dosed with fractions of extracts of polygyne queens, or blends of synthetic counterparts of queen cuticular compounds. We show that the queen supergene pheromone comprises a blend of monoene and diene unsaturated hydrocarbons. Our assays also reveal that unsaturated hydrocarbons elicit discrimination by polygyne workers only when associated with additional compounds that signal queen fertility. This synergistic effect was obtained with a polar fraction of queen extracts, but not by the piperidine alkaloids, suggesting that the chemical(s) indicating queen reproductive status are compounds more polar than cuticular hydrocarbons but are not the piperidine alkaloids. Our results advance understanding of the role of chemical signaling that is central to the regulation of social organization in an important invasive pest and model ant species.
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Cleo Bertelsmeier, along with Jérôme Gippet and Lorena George, have published a paper on the invasion of Tapinoma magnum in the lake Geneva region entitled: Local coexistence of native and invasive ant species is associated with micro-spatial shifts in foraging activity
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Summary: Invasive species often displace native species by outcompeting them. Yet, some native species can persist even in heavily invaded areas. The mechanisms mediating this local coexistence are still unclear. Fine-scale microclimatic heterogeneity could promote the local coexistence of native and invasive animal competitors. We tested if native ant species could coexist with a recent ant invader, Tapinoma magnum, by shifting their foraging activity in time or space to different microclimatic conditions. The foraging activity of native epigeic ant species was compared among invaded and uninvaded sites. We collected ants at baits in green spaces on the north, east, south and west sides of buildings in the morning, at noon and in the afternoon to test if native species foraged under different microclimatic conditions in invaded sites. Invaded sites had lower ant species richness, diversity, and relative abundance. The native black garden ant Lasius niger – one of the most widespread Palearctic ant species – persisted at high densities in invaded areas but foraged less on the east side of buildings and more on the west side. Microclimatic heterogeneity might promote native and invasive species coexistence by allowing some native species to shift their foraging behaviour to locally avoid or outcompete invasive competitors.
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Multiple researchers from the van de Waal group led by her former postdoc Dr. Sofia Forss, including PhD students Pooja Dongre and Tecla Mohr, as well as Dr. Alba Motes for Keller group, published paper in Animal Cognition entitled: Captive and habituated vervet monkeys are more curious than their wild conspecifics. The influence of captive environments and human exposure on cognitive mechanisms in animals remain poorly understood. Although diminished neophobia, resulting from a safer environment and more "free" time, has been proposed to cause intraspecific differences between wild and captive individuals, we know less about how human exposure influences exploration tendency. In this study, the authors refer to the combination of reduced neophobia and increased interest in exploring novelty as “curiosity”, which they systematically compared across seven groups of captive and wild vervet monkeys (Chlorocebus pygerythrus) by exposing them to a test battery of eight novel stimuli. In the wild sample, they included both monkeys habituated to human presence and unhabituated individuals filmed using motion triggered video cameras. Results revealed clear differences in willingness to approach novel artefacts and food items among captive, wild habituated and wild unhabituated monkeys. As foraging pressure and predation risks are assumed to be equal for all wild monkeys, these results do not support a relationship between curiosity and safety or free time. Instead, the authors propose "the habituation hypothesis" as an explanation of why well-habituated and captive monkeys both approached and explored novelty more than unhabituated individuals. We conclude that varying levels of human and/or human artefact habituation, rather than the risks present in natural environments, better explain variation in curiosity in our sample of vervet monkeys.
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The second, Genomic consequences of colonisation, migration and genetic drift in barn owl insular populations of the eastern Mediterranean, shows the barn owl populations of Crete and Cyprus come from different sources, while the last, Landscape and climatic variations shaped secondary contacts amid barn owls of the Western Palearctic, revisit the demographic history of barn owls in Europe in the light of whole genome sequences and identify a new refugium in the Italian peninsula during the last glaciation. These three chapters are real team efforts, with Tristan Cumer, Alexandros Topaloudis sharing first authorship with Ana, Anne-Lyse Roulin contributing to the first and Eleonore Lavanchy contributing to the second. Stay tuned for the last part of the story, looking at barn owls population genomics in the Canaries islands.
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To complete the feast, Jerome co-authored a Heredity paper Rank-invariant estimation of inbreeding coefficients, where he explores the statistical properties of several commonly used estimators of individual inbreeding coefficients and shows several to be inaccurate in admixed populations.
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While you are encouraged to place your publications into Serval, please make sure that your PI has validated the deposition first. Not all documents should be included in Serval, and they are complicated to remove.
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