The role of social structure in defining population dynamics of house mice in Australian cropping systems

The development of informed management strategies is necessary to mitigate the impacts of eruptive pest species in Australian agricultural systems. The ability to successfully maintain or reduce pest population density to below a damage threshold relies on identifying the critical regulators of population growth and stability. For many eruptive species, social structures are thought to strongly impact these key population parameters. Understanding how social structures translate to population-level dynamics is a key challenge, especially in small mammals. This study aims to investigate the underlying social mechanism(s) that might be influencing population dynamics. The study used a combination of spatially explicit capture-recapture models and single nucleotide polymorphisms (SNP) genotyping to test predictions of the self-regulation hypothesis proposed by Krebs et al., (1995) and Sutherland et al., (2005) using neighbouring house mouse (Mus musculus domesticus) populations that show distinctly different trajectories. Firstly, I test if space use in the spring (low population phase) differs between outbreaking and non-outbreaking populations. Secondly, I estimate pairwise kinship to test if female relatedness is higher during the spring in outbreaking populations and investigate changes in relatedness between different seasons. Females in outbreaking populations had lower home range overlap compared to non- outbreaking populations. Kinship was low between populations and seasons, however the non- outbreaking populations had a stable number of close relatives and resident mice over time. The study showed that female house mice have greater potential to form kin groups in more stable non-outbreaking populations during spring and early summer, thus, providing a foundation for future studies to investigate how these differences could help to improve management strategies.