Simona Kralj Fišer, PhD

Senior Research Associate

+386(0) 1 470 63 33


My prime research interests are causes and consequences of the intraspecies individual differences in behaviour, also refered to as personality differences. During my PhD I studied proximate mechanisms of personality expression in free-roaming greylag geese Anser anser finding that corticosterone modulation might be important for aggressiveness in birds (Kralj-Fišer et al. 2007 Horm Behav, Kralj-Fišer et al. 2010 J Ethol). In the course of postdoctoral research at the University of Hamburg (Prof. Dr. Jutta Schneider), I conducted the study on the bridge spiders Larinioides sclopetarius, a succefull dweller of urban areas occuring in high densities along rivers. We found that a balance between behavioural plasticity and stability might be crucial for their successful spread in cities. Moreover, through mate choice experiments in L. sclopetarius we studied how personality differences may be maintained through evolution. In our ongoing research (Dr. Kuntner) we compare our finding from L. sclopetarius studies with findings in another orb web spider Nuctenea umbratica. The later inhabit urban areas, but avoid artificial lights and never occur in high densities. In the context of personalities, we also test the  aggressive spillover hypothesis, i.e. a link between female general aggression (towards prey, same sex conspecifics) and sexual cannibalism (Kralj-Fišer et al. 2011 Behav Ecol Sociobiol). We found that female prospensity to cannibalize their mates depend on male quality (mate choice hypothesis) rather their general aggressiveness. The more aggressive was a male, the lower was the probability that female cannibalized him (sexy sons hypothesis). Beside personalities, current topics include sexual biology in nephilid spiders known for extreme sexual size dimorphism, male mutilation and female plugging (Kuntner et al. 2009 Zool; Kralj-Fišer et al. 2011 Anim Behav).

Mate quality, not aggressive spillover, explains sexual cannibalism in a size-dimorphic spider, Simona Kralj-Fišer, Jutta M. Schneider, Živa Justinek, Sabina Kalin, Matjaž Gregorič, Stano Pekár, Matjaž Kuntner. 2011

Individual- and condition-dependent effects on habitat choise and choosiness, Jonathan N. Pruitt, Nicholas Di Rienzo, Simona Kralj-Fišer, J. Chadwick Johnson, Andrew Sih. 2011

Olfactory discrimination of complex mixtures of amino acids by the black bullhead Ameiurus melas, Tine Valentinčič, Pika Miklavc, Simona Kralj-Fišer, Vera Zgonik. 2011

Coexistence of surface and cave amphipods in an ecotone environment, Roman Luštrik, Martin Turjak, Simona Kralj-Fišer, Cene Fišer. 2011

Eunuchs are better fighters, Simona Kralj-Fišer, Matjaž Gregorič, Shichang Zhang, Daiqin Li, Matjaž Kuntner. 2011

Glucocorticoids enhance and suppress heart rate and behaviour in time dependent manner in greylag geese (Anser anser), Simona Kralj-Fišer, Isabella Scheiber, Kurt Kotrschal, Brigitte M. Weiß, Claudia Wascher. 2010

Behavioural and physiological correlates of personality in greylag geese (Anser anser), Simona Kralj-Fišer, Brigitte M. Weiß, Kurt Kotrschal. 2010

Ladder webs in orb-web spiders : ontogenetic and evolutionary patterns in Nephilidae, Matjaž Kuntner, Simona Kralj-Fišer, Matjaž Gregorič. 2010

Mate plugging via genital mutilation in nephilid spiders : an evolutionary hypothesis, Matjaž Kuntner, Simona Kralj-Fišer, J. M. Schneider, Daiqin Li. 2009

Individualities in a flock of free-roaming greylag geese : behavioral and physiological consistency over time and across situations, Simona Kralj-Fišer, Isabella Scheiber, Andrej Blejec, Erich Möstl, Kurt Kotrschal. 2007

Sampling effort/frequency necessary to infer individual acute stress responses from fecal analysis in Greylag geese (Anser anser), Isabella Scheiber, Simona Kralj-Fišer, Kurt Kotrschal. 2005


  • B.S. (Biology), University of Ljubljana, Slovenia (2002)
  • Ph.D. (Biology), University of Ljubljana, Slovenia (2009)



  • Associate Professor in Ethology (2018-2023), University of Primorska, Slovenia
  • Assistant Professor in Ethology (2018-2023), University of Ljubljana, Slovenia
  • Research fellow (2018 – 2023), Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana (ZRC SAZU), Slovenia



  • Research fellow (2012 to present), research assistant (2009-2012), young researcher (2006-2009), Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
  • Lecturer (2013-present), University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies, Slovenia
  • Post-doctoral Researcher (2010-2011), Behavioural Biology, University of Hamburg, Germany (Prof. Dr. Jutta Schneider)
  • PhD student (2003), Konrad Lorenz Research Station for Ethology, Gruenau, Austria & University of Vienna, Austria (Prof. Dr. Kotrschal)



  • Principal Investigator of Evolutionary Zoology Laboratory (2018-present), Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia



  • Behavioural biology: personalities in nonhuman animal, sexual behaviour and behavioural plasticity
  • Evolution: evolution of sexual biology and sexual size dimorphism
  • Ecology: behaviour and life histories strategies in ecology, specifically ecology of human altered environments (urbanization, global climate change)



  • Humboldt Foundation postdoctoral project (2010-2011): Behavioural types underlying invasiveness in bridge spider and its consequences for community structure
  • Humboldt Foundation Return Fellowship (2011): Assortative mating by personality types in an orb-viewing spider
  • ARRS post-doctoral project (2011-2013): Behavioural mechanisms underlying species invasiveness (Z1-4194)



  • Lecturer of Behavioural genetics (2013-present), University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies (FAMNIT UP), Slovenia.
  • Mentor of bachelor theses: Nastja Ugrin (FAMNIT UP, 2017); Lara Samojlenko (FAMNIT UP, 2016); Andrej Katarinčič (FAMNIT UP, 2016); Lara Gregorčič Vidović (FAMNIT UP, 2016); Zali Slabe (FAMNIT UP, 2015)
  • Master thesis: Urška Pristovšek (Biotechnical faculty, University of Ljubljana, 2013), Nina Šramel (FAMNIT UP, 2017); Tina Cokan (FAMNIT UP, 2017), Lučka Vavpotič (FAMNIT UP, 2017), Rok Golobinek (Biotechnical faculty, University of Ljubljana, 2018)
  • Ongoing PhD mentoring: Shakira Quinones-Lebron (ZRC SAZU), Eva Turk (ZRC SAZU), Rok Golobinek (Biotechnical faculty, University of Ljubljana)
  • Regular academic committee member at the FAMNIT UP and University of Ljubljana



  • Academic editorial board: editorial board at Hacquetia (2009-present)
  • Conference programme committee member: 27th European Congress of Arachnology, Ljubljana, Slovenia (2012); 15th Conference of the International Society for Behavioral Ecology (ISBE), New York, USA; 31st European Congress of Arachnology, Vac, Hungary (2018)
  • Peer review: Proceeding of the Royal Society B, American Naturalist, Journal of Animal Ecology, Evolutionary Ecology, Evolution and Ecology, Journal of Evolutionary Biology, Biology Letters, Scientific Reports, Animal Behaviour, Behavioral Ecology, Behavioral Ecology and Sociobiology, Ethology, Behaviour, Hormones and Behavior, Behavioral Processes, Physiology and Behavior, Plos One, Conservation Biology, Animal Cognition, Current Zoology, Naturwissenschaften, Zoology, Journal of Arachnology (



  • Best young researcher (2010): Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia.
  • Best poster award at 27th European Congress of Arachnology, Ljubljana, Slovenia, 2012. Authors: Pristovšek, Urška, Kralj-Fišer, Simona, Kuntner, Matjaž.