A comparison of two species of bandicoots (Perameles nasuta & Isoodon obesulus) influenced by urbanisation: population characteristics, genetic diversity, public perceptions, stress and parasites
thesisposted on 2022-03-28, 20:11 authored by Matthew Dowle
Bandicoot populations and species such as the southern brown bandicoot (Isoodon obesulus) are in decline throughout Australia, with the notable exception of the long-nosed bandicoot (Perameles nasuta). Urbanisation is a major contributor to this decline, creating habitats that are unfavourable to the long-term persistence of many native species. Knowledge of how animals cope with their environment and adapt to its changes is fundamental to the management of urban and wild populations. This study investigated issues pertaining to the management of two bandicoot species in a wild (National Park) and peri-urban (backyard) setting in northern Sydney. Specifically, the study provided an ecological snapshot, examined parasite loads (Cryptosporidium and ecto-parasites), investigated stress levels through faecal glucocorticoid metabolites (FGMs), defined genetic diversity and gene flow across populations and explored public perceptions of the local community towards bandicoots. -- The attitudinal survey provided context behind the conflicts between bandicoots, humans and domestic pets. A direct interaction, the age of a respondent and pet ownership was pivotal in influencing the respondents' perception of a bandicoot. Live trapping and hair-tube surveys revealed a single I. obesulus record outside Ku-ring-gai Chase National Park. Genetic analysis identified gene flow, albeit low, between the long-nosed bandicoots of Ku-ring-gai Chase and Garigal National Park, suggesting a single interbreeding population. Through similar genetic history, ecological traits and sympatric nature in Ku-ring-gai Chase, connectivity of habitat between the two National Parks is also likely to be present for the southern brown bandicoot. FGM analysis of long-nosed bandicoots revealed that capture overnight did not represent a prolonged physiological response. Additionally, FGM analysis failed to detect a difference across habitat types and between body condition values of bandicoots. This was despite the presumed increased risks of obtaining resources in the more open suburban backyard environments. The parasite analyses observed bandicoots on the urban interface carrying the paralysis tick (Ixodes holocyclus) and potential zoonotic types of Cryptosporidium. It also highlighted the opportunity for the transmission of parasites to occur between host species in an area of elevated contact between wildlife, humans and domestic pets. The information generated from the investigations will find application with the bandicoots of northern Sydney and provide management with suitable information to employ conservation strategies conducive to the persistence of threatened and non-threatened Australian fauna, particularly I. obesulus.