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.