Linking stress and individual behavioural variation

Stress is thought to play a central role in shaping and stabilizing consistent individual behavioural variation. While the relationship between stress, behavioural type, and plasticity (coping style) has been explored, empirical data from natural populations are still scarce. Stress in ecology is often defined as a condition in which environmental demands exceed an organism’s natural regulatory capacity, while a stressor is any factor that pushes the organism beyond its adaptive capacity. However, this definition tends to overlook mild stress, where the stressor remains within the organism’s tolerance range but still affects its function. While varying stress intensities are expected to influence individual behavioural variation, there is limited empirical evidence on how mild versus severe stress affects specific behavioural components. Furthermore, stress intensity may alter the relationships between behavioural traits and other repeatable phenotypic traits, an area that remains underexplored.

The project aims to explore how varying stress levels influence individual behavioural variation, the interactions between behavioural components, and the relationships between behaviour and other phenotypic traits. Specifically, the project aims to investigate: (1) the role of mild versus acute stress in the development, stabilization, and degradation of individual behavioural strategies, the effects of stress on components of behavioural variation, and the correlations between them; (2) how stress influences the relationship between behaviour and other repeatable traits such as physiology and thermoregulation; (3) how multiple stressor environments affect individual behavioural variation; and (4) the impact of maternal stress and its transgenerational effects on the repeatable phenotypic traits and behavioural coping styles of offspring.