Seasonal density fluctuations of the exotic ornate kangaroo tick, Amblyomma triguttatum triguttatum Koch, and its distribution on Yorke Peninsula, South Australia

Mammal parasites in arid Australia

The helminth and arthropod parasite communities occurring in macropodid, vombatid and notoryctid marsupials as well as in rodents in the arid zone of Australia are compared with those found in related host species in adjacent semi-arid and humid zones and are also related, where possible, to the changes in the mammalian fauna of central Australia over a geological time scale. Across the marsupials and rodents for which parasitological data are available, there is an obvious contrast in the helminth communities between inhabitants of high rainfall areas and those inhabiting semi-arid and arid zones in terms of parasite genera present in the marsupials. The differences between the inhabitants of semi-arid and arid environment communities are less overt and are observable only the parasite species level in the case of the kangaroos and wallabies. In the case of the rodents, there appears to be a significant lack of diversity in helminth faunas associated with the transition to an arid environment. Differences in the arthropod parasite communities between climatic regions are more marked than is the case with the helminths. The general lack of life cycle studies of these parasites provides an impediment to identifying the means by which they have adapted to the increasing aridity in central Australia over geological time, but appears to offer opportunities for future study.

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Not really applicable to review articles.

Investigation of ticks and red blood cell parasites of a population of reintroduced mainland tammar wallabies (Notamacropus eugenii eugenii)

Ticks and blood smears were collected from a reintroduced population of threatened tammar wallabies (Notamacropus eugenii eugenii). Ixodes hirsti was common during autumn/winter, and Amblyomma spp. in spring/summer, reflecting the seasonal density of questing A. triguttatum triguttatum. Red blood cell parasites were not detected in the 90 smears analysed.

Responses to a survey question on the distribution of western pygmy-possums (Cercartetus concinnus) on Yorke Peninsula, South Australia

The western pygmy-possum (Cercartetus concinnus) is probably the last remaining small native ground-dwelling mammal on Yorke Peninsula. We surveyed 1013 Yorke Peninsula residents about the distribution of pygmy-possums on the peninsula. Thirteen of 296 respondents had seen pygmy-possums, none north of Minlaton. Two additional possum species had also been seen.

Population characteristics of house mice (Mus musculus) on southern Yorke Peninsula, South Australia

Seasonal population characteristics of house mice (Mus musculus), including the effect of season on body mass, were studied at Innes National Park, southern Yorke Peninsula. Mice were caught with Elliott traps, ear-notched, and released. Over 1550 trap-nights (January to December 2006, excluding May), 202 mice were caught. The overall capture success rate was 13.03 mice per 100 trap-nights. The recapture rate was 42.57%. Body mass of adult house mice varied significantly among seasons (P = 0.009). In particular, mouse body mass varied between autumn and winter (P = 0.018), and spring and winter (P = 0.023). The body mass of mice captured in autumn and then recaptured in winter was also significantly different (P = 0.006). This study is the first published for M. musculus population characteristics on Yorke Peninsula and adds to the relatively limited information available on house mouse populations in non-agricultural habitats.

Human perception and awareness of ticks in a South Australian rural community and implications for management of Amblyomma triguttatum triguttatum

The ornate kangaroo tick, Amblyomma triguttatum triguttatum, is invasive on Yorke Peninsula, South Australia. To assess the potential for developing comprehensive management strategies for the species, we mailed 1,000 surveys to Yorke Peninsula residents to investigate community perceptions of ticks, gather information on tick-host ecology, and assess whether or not occupation and length of residence affected whether residents had seen ticks. The response rate was 32%; most respondents (63%) had not seen ticks on Yorke Peninsula. Of those who had (n = 104), 56% had seen ticks on animals, especially lizards (31%) and kangaroos (20%); 50% had seen ticks on humans. Of the 64 respondents who believed places on Yorke Peninsula had many ticks, 56% identified Innes National Park and 75% areas on southern Yorke Peninsula. The likelihood of seeing ticks was not related to occupation. Whether respondents had seen ticks was related to length of residence on Yorke Peninsula (<10 years = 23.6%, 10-30 years = 44.0%, 31-50 years = 47.6%, 51-70 years = 30.9%, 71+ years = 21.4%). The number of respondents who had seen ticks on humans suggests that tick-borne diseases could become a public health issue on Yorke Peninsula. This finding is of particular concern because A. t. triguttatum is implicated in the epidemiology of Q fever in Queensland. Finally, respondents were unaware of the responsibility for tick management, which demonstrates a need for collaboration amongst stakeholders.

Understorey predicts the spatial distribution of Ixodes hirsti in South Australia

Ticks reduce the fitness of their host by increasing mortality rate and reducing reproductive success. Understanding the distribution of ticks is therefore crucial in assessing the vulnerability of host populations. The distribution of ticks is dependent on the dispersal capabilities of their hosts as well as the suitability of the new habitat. In this study, we examine the spatial distribution of Ixodes hirsti in South Australia and investigate the influence of vegetation characteristics on the presence of ticks. Additionally, we conducted a preliminary investigation into the effects of vegetation characteristics on the microclimate experienced by questing ticks. Ticks were present in six of the nine study sites. We found that the number of shrubs and the percentage of ground covered by shrubs were significant predictors of the presence of ticks: ticks were present only at sites with a dense cover of shrubs. Additionally, our preliminary data showed that dense understorey was associated with a low saturation deficit and, as such, provided a suitable microclimate for tick survival.

Hosts of the exotic ornate kangaroo tick, Amblyomma triguttatum triguttatum Koch, on southern Yorke Peninsula, South Australia

Amblyomma triguttatum triguttatum is assumed to be endemic to south-western Western Australia (including Barrow Island), Queensland (excluding Cape York Peninsula), and New South Wales, south to Dubbo and Barham. The species has been recorded on a range of mammalian hosts including macropods and domestic animals. In Queensland, A. triguttatum triguttatum is implicated in the epidemiology of Q fever. In 2000, the species was detected on southern Yorke Peninsula in South Australia. We aimed to identify A. triguttatum triguttatum's hosts through trapping, sampling of carcasses, and opportunistic capture of vertebrates on Yorke Peninsula. A. triguttatum triguttatum was removed from black rats (Rattus rattus), wild rabbits (Oryctolagus cuniculus), western grey kangaroos (Macropus fuliginosus), Tammar wallabies (M. eugenii eugenii), domesticated cats and dogs, and humans. Before this study, A. triguttatum triguttatum had not been found on black rats or rabbits in the wild. This research has implications for the management of wildlife, livestock, and visitors on Yorke Peninsula. The potential for A. triguttatum triguttatum to spread to other areas of Yorke Peninsula and South Australia is considerable, as visitors (tourists) to southern Yorke Peninsula report the presence of ticks both on themselves and among camping equipment on arriving home.