Individual activity of forest rodents correlates to pathogen communities

Animal personality influences organismal interactions and individual habitat use. Rodents are zoonoses reservoirs and often exposed to several pathogens simultaneously, potentially resulting in interdependence of infections and susceptibility to infection. Still, entire pathogen communities are rarely investigated, even though, given rodents ubiquity in human settlements, understanding the link between animal personality and pathogenesis is an important public health issue. We investigated the association of animal personality with pathogen communities in wild rodents, analysing ectoparasite occurrence and pathogenic bacteria of 93 individuals belonging to 3 species from urban and forest areas around Potsdam, Germany. Individual personality was quantified using a combination of open-field and dark-light test. Rodents were then euthanised and screened for pathogens in the spleen through 16 S rRNA amplicon sequencing, and ectoparasites were collected. We detected 6 pathogenic bacteria and 3 ectoparasite taxa. Host species and sampling time explained most of the variation in pathogen associations, but within each genus, 7-9% of the variation was explained by animal personality. Active rodents were more likely infected by Bartonella than less active ones. Bold animals had lower tick infestation probabilities. Thus, animal personality contributes to the distribution and prevalence of pathogens in wild rodents, and should be considered in epidemiology and disease management.