Four macropods inhabit the rocky habitats of the tropics of the Northern Territory, Australia (Macropus bernardus, M. robustus, Petrogale brachyotis and P. concinna). This is an unusually high diversity of rock-dwelling macropods, and their sympatry and varied distributions raise many interesting questions about their ecology and mechanisms of niche separation. The species are also some of the least studied macropods in Australia and methods to study their ecology have scarcely been trialled. To examine the ecology of this unique fauna group, I used a multi-disciplinary approach that combined recording indigenous knowledge with a broad range of scientific techniques. I found indigenous consultants held detailed knowledge of the habitat preferences, diet, activity patterns, reproduction and predation of the four species, which suggested some differences in the comparative ecology of the species. I examined whether scats can be used as a survey tool for these species and showed scats can accurately indicate their presence and broad habitat preferences. I conducted a GIS analysis and survey (using scats) of the species’ habitat requirements, which suggested M. bernardus and P. concinna are more specialised and have greater requirements for rugged terrain, whereas M. robustus and P. brachyotis are more generalist in their habitat selection. I used a macroscopic and isotopic analysis of scats to examine the species’diets. The study found the diets of the species varied across the landscape and with season, and that M. bernardus may rely more heavily on browse than M. robustus. Using radio-telemetry I found in the dry season P. brachyotis uses a small home range and a range of shelters within that home range. Finally, I examined the relatedness and genetic diversity of seven colonies of P. brachyotis and found dispersal between colonies to be limited at > 1.2 km and remarkable mtDNA divergence exists within some colonies. This research described many aspects of the ecology of the rock-dwelling macropods and highlighted some differences between the species that may contribute to their niche differentiation.
|Date of Award||2006|
|Supervisor||Anthony Griffiths (Supervisor) & David Bowman (Supervisor)|