Studying pathogen transmission and related risks in the wild is notoriously difficult as it is difficult to conduct experimental studies. Nevertheless, population perturbation studies are one way of inducing experimental changes in animal communities. Indeed, there are a number of perturbation under way all the time in cities as pest management operators are doing lethal control of rodent populations.
Pest management actions are motivated by the need to reduce the population sizes of rodents in order to safeguard human and domestical animal health. Nevertheless, the actual efficiency of this is unknown. While it is intuitively sensible that less rats means less pathogen spread and lower risks to humans, ecologists know that this is not always the case. There are a number of cases where culling has actually increased transmission risks through the population perturbations leading to changing movement patterns and less social cohesion. Well-known examples include badger culls in England and increased transmission of bovine tuberculosis and bat roost disturbance and Marburg virus spread.
A wealth of new information will be collected in the following four years, as Academy of Finland has granted Academy Research Fellowship for Tuomas Aivelo to continue on urban rat pathogen studies. Thus, starting in September, Helsinki Urban Rat Project will start a new four-year research project called “Urban rats as a model species for disease ecology”. Academy of Finland has granted 880 000 euros for this project and it will include a full-time work for two researchers, Tuomas Aivelo and for a postdoc whose recruitment is currently under way.
The aim of the research project is to look at rat pathogen and parasite prevalence, rat movement and population genetic structure prior to and after pest management actions, i.e., killing of the rats. This will improve our understanding of the practical implications of pest management but also it will provide a wealth of basic research on how animal movement on different scales effects parasite and pathogen risks.