Academic Education
12/2016 - 05/2020	Ph.D. studies at the Institute for Neuro- and Behavioural Biology, University of Münster
10/2013 - 08/2016	Master of Science in Biosciences, University of Münster
10/2010 - 09/2013	Bachelor of Sciene in Biosciences, University of Münster
Work Experience
since 06/2020	Postdoctoral researcher at the Department of Behavioural Biology, University of Münster
12/2016 - 05/2020	PhD student at the Department of Behavioural Biology, University of Münster

The behavioural ecology of optimism: judgement bias and foraging under predation risk in mice Bračić M, Bierbaum L, Peng M, Nimalavachchlan L, Siewert V, Kaiser S, Sachser N, Richter SH (2025) In: Animal Behaviour, 219, 122991. doi:10.1016/j.anbehav.2024.10.005 Research article (journal) \| Peer reviewed \| Published
Optimism and pessimism: a concept for behavioural ecology Siewert V, Kaiser S, Sachser N, Richter SH (2025) In: Biological Reviews of the Cambridge Philosophical Society, 100, 1152-1162. doi:10.1111/brv.13178 Research article (journal) \| Peer reviewed \| Published
Forever an optimist? Investigating the temporal consistency of optimism within and across life phases in rats Bierbaum L, Mundinger C, Siewert S, Kaiser S, Richter SH (2025) In: Animal Behaviour, 229, 123334. doi:10.1016/j.anbehav.2025.123334 Research article (journal) \| Peer reviewed \| Published
The power of a touch: Regular touchscreen training but not its termination affects hormones and behavior in mice Quante, SM; Siewert, V; Palme, R; Kaiser, S; Sachser, N; Richter SH (2023) In: Frontiers in Behavioral Neuroscience, 17. doi:10.3389/fnbeh.2023.1112780 Research article (journal) \| Peer reviewed \| Published
Once an Optimist, Always an Optimist? Studying Cognitive Judgment Bias in Mice Bračić M, Bohn L, Siewert V, von Kortzfleisch V, Schielzeth H, Kaiser S, Sachser N, Richter SH (2022) In: Behavioral Ecology, 33, 775-788. Research article (journal) \| Peer reviewed \| Published

The behavioural ecology of optimism: judgement bias and foraging under predation risk in mice Bračić M, Bierbaum L, Peng M, Nimalavachchlan L, Siewert V, Kaiser S, Sachser N, Richter SH (2025) In: Animal Behaviour, 219, 122991. doi:10.1016/j.anbehav.2024.10.005 Research article (journal) \| Peer reviewed \| Published
Optimism and pessimism: a concept for behavioural ecology Siewert V, Kaiser S, Sachser N, Richter SH (2025) In: Biological Reviews of the Cambridge Philosophical Society, 100, 1152-1162. doi:10.1111/brv.13178 Research article (journal) \| Peer reviewed \| Published
Forever an optimist? Investigating the temporal consistency of optimism within and across life phases in rats Bierbaum L, Mundinger C, Siewert S, Kaiser S, Richter SH (2025) In: Animal Behaviour, 229, 123334. doi:10.1016/j.anbehav.2025.123334 Research article (journal) \| Peer reviewed \| Published
The power of a touch: Regular touchscreen training but not its termination affects hormones and behavior in mice Quante, SM; Siewert, V; Palme, R; Kaiser, S; Sachser, N; Richter SH (2023) In: Frontiers in Behavioral Neuroscience, 17. doi:10.3389/fnbeh.2023.1112780 Research article (journal) \| Peer reviewed \| Published
Once an Optimist, Always an Optimist? Studying Cognitive Judgment Bias in Mice Bračić M, Bohn L, Siewert V, von Kortzfleisch V, Schielzeth H, Kaiser S, Sachser N, Richter SH (2022) In: Behavioral Ecology, 33, 775-788. Research article (journal) \| Peer reviewed \| Published