Y.H. (Yoran) Gerritsma

In wildlife, human, and laboratory animal populations, considerable variability exists among individuals in their trait-like patterns of behavioural and physiological responses to salient environmental challenges and opportunities. This individual variation in so-called personalities has important functional consequences in terms of fitness of the individual.

Although individual differences in personality traits can be explained from an evolutionary point of view and have a significant heritable component, as well as a proximate basis in genetic polymorphisms and associated neurobiology, personality nevertheless has substantial phenotypic plasticity and can be profoundly affected by adverse environmental conditions particularly when they act during early development. Surprisingly, the origin and exact mediating mechanisms of this environmental component is currently not well understood. It seems likely that at least part of the personality variation will arise during early development, because early development is well known to affect fitness expectations. To better understand the plasticity of personality variation, I will therefore investigate the effect of developmental manipulations with ecological validity on animal personality and its proximate neurobiological causes.

This project builds on a recently started Adaptive Life project on zebra finches housed in outdoor aviaries, with either ‘easy’ or ‘hard’ foraging conditions (See "Joint Project - M.M.G. Driessen" below). By manipulating the foraging conditions of the parents, we influence the developmental conditions of the offspring, as we expect less parental care and more sibling competition in hard foraging conditions.

Recent findings indicate that variation in developmental conditions causes differences in certain aspects of personality, e.g. sociality, flexibility and dominance. Avian personality will be assessed using a wide array of behavioural tests covering different personality dimensions, including tests of social dominance, boldness, exploration, and socia(bi)lity, and we will determine the relationships between these different behavioural traits of personality.

Summary:
In my project, I will investigate the effect of early developmental environment manipulations on (1) avian personality traits including sociality in adulthood and (2) selective neuromolecular mechanisms underlying the behavioural expressions of personality.

(MSc) Projects are possible under my supervision. Contact me if you are interested in personality, development, reproduction, or the neurobiology underlying behaviour!