Parasitic infection alters rodent movement in a semiarid ecosystem

Parasite-mediated behavioral changes in their hosts have been documented in many species, but field evidence is scarce. The protozoan Trypanosoma cruzi is transmitted by insect vectors to several mammal species. Although previous studies have shown high levels of infection in hosts and vectors, it is unknown if this protozoan affects movement behavior of mammal reservoirs. Here we examine, under natural conditions, the existence of movement alterations in two species of rodents (Octodon degus and Phyllotis darwini) when infected with T. cruzi, evaluated for four consecutive years. We found that infected O. degus traveled shorter distances than those non-infected, the opposite was found for P. darwini. We also detected a strong inter-annual effect for both species. Our results show that rodent species respond differentially to T. cruzi infection in regard to their movements, which may have implications in disease spreading.