The role of social environments in personality-related settlement decisions in a wild passerine bird

• Applicant: Benedikt Holtmann, Ph.D.
• Subject Area: Sensory and Behavioural Biology ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 406544150

Repeatable individual differences in behaviour (often referred to as “animal personality”) are ubiquitous among animal species. In recent years, evidence has accumulated that individuals do not disperse randomly, but aggregate in habitats that best match their own personalities. Such non-random assortment of behavioural phenotypes may have implications for an individual’s fitness, as well as the social dynamics of the whole population. While theoretical concepts of the interplay between animal personality, the distribution of behavioural phenotypes, and the social environment have been developed, their relationship remains poorly understood in natural populations. Here, I propose a project that aims to investigate how social structures within wild populations drive the assortment of behavioural phenotypes (and vice versa) and what fitness consequences result from such interactions. I will use the great tit (Parus major) – a key species in animal personality research – as a study system. The proposed project consists of two tightly connected research parts. First, I will make use of an ongoing long-term study of 12 nest box populations of great tits, for which personality traits and their distribution have been recorded since 2009. Specifically, I will examine how the composition of the local social environment affects the settlement and fitness of different behavioural phenotypes. Second, I will set up six additional experimental nest box plots to perform targeted manipulations of the social environment over a period of three years. In particular, I will use winter food supplementation to alter breeding densities, and remove specific territorial males of known behavioural phenotypes (e.g. aggressive vs. non-aggressive). These manipulations will allow me to test if individuals actively settle in social neighbourhoods, which match their own personalities, or whether settlement is a random process. In addition, repeated behavioural measurements within and across years will reveal if individual birds adjust their behaviour (i.e. within-individual changes) as their social neighbourhood changes. Overall, the proposed project will advance our understanding of how selection acts on behavioural traits and provide novel insights into the ecological and evolutionary dynamics of the spatial structuring of communities in natural populations.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Niels Dingemanse