Understorey predicts the spatial distribution of Ixodes hirsti in South Australia

Abstract

Ticks reduce the fitness of their host by increasing mortality rate and reducing reproductive success. Understanding the distribution of ticks is therefore crucial in assessing the vulnerability of host populations. The distribution of ticks is dependent on the dispersal capabilities of their hosts as well as the suitability of the new habitat. In this study, we examine the spatial distribution of Ixodes hirsti in South Australia and investigate the influence of vegetation characteristics on the presence of ticks. Additionally, we conducted a preliminary investigation into the effects of vegetation characteristics on the microclimate experienced by questing ticks. Ticks were present in six of the nine study sites. We found that the number of shrubs and the percentage of ground covered by shrubs were significant predictors of the presence of ticks: ticks were present only at sites with a dense cover of shrubs. Additionally, our preliminary data showed that dense understorey was associated with a low saturation deficit and, as such, provided a suitable microclimate for tick survival.