Stress and parasite infection dynamics in wildlife translocation

Translocation, the deliberate relocation of animals from one site to another to establish new colonies or supplement declining populations, may involve several potential stressors (challenging stimuli), including: capture, handling, confinement, transport and release into an alien environment. Given that stress is associated with altered immune function, it has been hypothesized that the stress of translocation may exacerbate the impact of infectious disease on translocated wildlife. However, despite the potential ramifications for translocation success, stress and infection parameters are rarely assessed in parallel during wildlife translocations. We aimed to test this hypothesis by investigating the stress response of woylies (Bettongia penicillata), critically endangered Australian marsupials, to translocation and explore implications for parasite infection dynamics. In 2014, individually identified woylies (n=182) were translocated from a sanctuary to two reserves in south-west Western Australia. Fecal cortisol metabolites of translocated woylies and resident woylies at the destination sites were measured at different stages of the translocation (pre-, at and post-). Parallel parasite measures were also assessed including: PCR to detect haemoparasitaemia (Trypanosoma spp.) and simple fecal flotation for gastrointestinal helminth eggs (strongyle spp, strongyloides spp) and coccidia oocysts. We found that cortisol metabolites varied significantly at different stages of the translocation. However, this variation in FCM could not explicitly be attributed to a stress response to translocation. Our results would also suggest that the stress physiology of translocated woylies did not significantly influence parasite infection dynamics. These results are pertinent given that translocation is a mainstay of conservation management for woylies and other endangered species.