Evaluating Stress Physiology and Parasite Infection Parameters in the Translocation of Critically Endangered Woylies (Bettongia penicillata)

Abstract

Translocation can be stressful for wildlife. Stress may be important in fauna translocation because it has been suggested that it can exacerbate the impact of infectious disease on translocated wildlife.However, few studies explore this hypothesis by measuring stress physiology and infection indices in parallel during wildlife translocations. We analysed faecal cortisol metabolite (FCM) concentration and endoparasite parameters (nematodes, coccidians and haemoparasites) in a critically endangered marsupial, the woylie (Bettongia penicillata), 1-3 months prior to translocation, at translocation, and 6 months later. FCM for both translocated and resident woylies was significantly higher after translocation compared to before or at translocation. In addition, body condition decreased with increasing FCM after translocation. These patterns in host condition and physiology may be indicative of translocation stress or stress associated with factors independent of the translocation. Parasite factors also influenced FCM in translocated woylies. When haemoparasites were detected, there was a significant negative relationship between strongyle egg count and FCM. This may reflect the influence of glucocorticoids on the immune response to micro-and macro-parasites. Our results indicate that host physiology and infection patterns can change significantly during translocation, but further investigation is required to determine how these patterns influence translocation success.

Next generation sequencing reveals widespread trypanosome diversity and polyparasitism in marsupials from Western Australia

“…Physiological differences such as stress and immune function could be contributing to more diverse parasite infections. Although, no real evidence exists that immune function is compromised in the remaining woylie populations, a collaborative study carried out in the UWR using faecal cortisol metabolite (FCM) concentration as an indicator of stress did find higher FCM concentrations in woylies (both translocated and resident) after translocation ( Hing et al, 2017 ). Lastly, epidemiological factors such as population size and status between the species could also result in differences in their exposure to trypanosome vectors or their susceptibility to infection.…”

“…AAT reported in the marsupial Bettongia lesueur (boodie) ( Averis et al, 2009 ). The presence of avian trypanosomes in marsupials could be explained by opportunistic infection from increased susceptibility associated with depressed immune function and/or stress as discussed above ( McInnes et al, 2011 , Hing et al, 2017 ). Trypanosoma irwini was found for the first time in WA and this is the first occurrence of this parasite infecting a marsupial other than the koala ( McInnes et al, 2009 , McInnes et al, 2011 , Barbosa et al, 2017 ).…”

The marsupial trypanosome Trypanosoma copemani is not an obligate intracellular parasite, although it adversely affects cell health

“…Many native marsupials in Australia are vulnerable or endangered and under stress. While T. copemani could contribute to ill health in the woylie [ 20 , 21 , 49 – 51 ], whether it causes clinical trypanosomiasis remains unknown. Previous ecological evidence suggests that T. copemani may have been involved in, but not directly responsible for, the decline of the woylie [ 20 , 23 , 43 , 52 ].…”

“…Previous ecological evidence suggests that T. copemani may have been involved in, but not directly responsible for, the decline of the woylie [ 20 , 23 , 43 , 52 ]. The remaining woylie populations could be stressed and thus immunosuppressed [ 49 ], which may affect the resident parasite population and normal host-parasite relationships. This perhaps allows cell invasion by a parasite that is a facultative intracellular pathogen.…”

Identification of a novel species of Eimeria Schneider, 1875 from the woylie, Bettongia penicillata Gray (Diprotodontia: Potoroidae) and the genetic characterisation of three Eimeria spp. from other potoroid marsupials

“…the eastern grey kangaroo Macropus giganteus Shaw; Barker et al, 1972). Given the reliance of many threatened species on interventional management practices such as translocation, a process which has been identified as a significant stressor (Hing et al, 2017), it is imperative that we gain a greater understanding of the parasite species infecting wildlife, particularly those with the potential to cause disease in their host (e.g. coccidian parasites).…”