The ecology, conservation status and management of a tropical kangaroo, the Antilopine Wallaroo (Macropus antilopinus) on Cape York Peninsula

A project undertaken at the James Cook University, Townsville and supervised by E Ritchie

N.B. Please contact the project supervisor before using any of the information on this page

The principal aim of this study was to determine the current population status and document the ecology of the Antilopine Wallaroo (M.antilopinus). This was achieved through intensive systematic study at a local scale in North Queensland, and broad-scale surveys, which ranged from the Einasleigh Uplands and Cape York Peninsula in Queensland, across the Top End of the Northern Territory and the Kimberley Region of Western Australia.

Specific aims of the study were:

  • To identify and model the environmental factors limiting the distribution and abundance of the antilopine wallaroo
  • To conduct a detailed investigation of ecology, documenting diet, habitat utilisation, social behaviour and reproduction.
  • To assess the current population status of the species, and assess its vulnerability to regional climate change

Major results

Distribution and abundance
  • 50 sites were surveyed across Northern Australia between 2002-2005, 150,000km distance traveled and >2000km of survey effort (Fig.1)
  • Sites noting historical declines were surveyed and antilopine wallaroos were recorded from 2/3 sites. In total antilopine wallaroos were recorded at 34/50 (68%) sites surveyed across northern Australia.
  • Antilopine wallaroo distribution and abundance at the large scale is controlled by the availability of permanent water, frequency of late-season fires, geology and land management. Within Queensland the abundance of eastern grey kangaroos was also found to be important, indicating potential competition between the two species. At finer scales, habitat structure was important (see Ritchie et al. 2008, Ecological Monographs 78, 105-122).
Social behaviour
  • The largest single group of antilopine wallaroos recorded was 17, with larger aggregations of >30 also occurring.
  • The antilopine wallaroo is the most gregarious of all macropods in northern Australia, with group composition changing throughout the year related to the breeding period.
  • There is a high degree of sexual segregation in this species, with all-female and all-male groups often observed. The mechanism behind this behaviour requires further investigation but may be related to foraging behaviour (see Fossan, P. (2005) Intraspecific differences in diet selection in a population of antilopine wallaroos, Macropus antilopinus (Marsupialia: Macropodidae) in north Queensland, Australia. Master of Applied Science thesis, James Cook University).
  • Births appear to occur in the summer months (Feb-March) and pouch young vacate the pouch at the beginning of the wet season (Nov-Dec).
Climate change and conservation
  • A map incorporating a BIOCLIM model of the antilopine wallaroo’s current distribution is presented (Fig 2).
  • Climate modeling indicates that the antilopine wallaroo may be at significant risk of extinction in the future. Models indicate that with temperature increases of 2.0 °C the distribution of the antilopine wallaroo may be reduced by up to 90% (see Ritchie, E.G. and Bolitho, E.E.(in press) Australia’s savanna herbivores: bioclimatic distributions and an assessment of the potential impact of regional climate change. Physiological and Biochemical Zoology)

Publications

Published/In press
  1. Richie, E.G., Martin, J.K., Johnson, C.N. and Fox, B.J. (2009) Separating the influences of environment and species interactions on patterns of distribution and abundance: competition between large herbivores. J.Animal Ecology Published Online: DOI: 10.1111/j.1365-2656.2008.01520.x (View as PDF here)
  2. Ritchie, E.G., Martin, J.K., Krockenberger, A.K.Garnett, S., and Johnson, C.N. (2008) Large herbivore distribution and abundance in the tropics: intra- and inter-specific niche variation across species' ranges. Ecological Monographs 78, 105-122 (View as PDF here)
  3. Ritchie, E.G. (2008) Antilopine wallaroo (Macropus antilopinus) species account. In Mammals of Australia, ed. S., Van Dyck. (book chapter)
  4. Ritchie, E.G. and Bolitho (2008), E.E. Australia’s savanna herbivores: bioclimatic distributions and an assessment of the potential impact of regional climate change. Physiological and Biochemical Zoology 81(6), 880-890 (View as PDF here)
  5. Ritchie, E.G. (provisionally accepted) Ecology and conservation of the antilopine wallaroo (Macropus antilopinus): an overview. Proceedings of the Macropod Symposium, Australian Mammal Society (book chapter)
In preparation
  1. Ritchie, E.G., Fox, B., Martin, J.K. and Johnson C.N. An assessment of the potential for interspecific competition between two large herbivores, the antilopine wallaroo (Macropus antilopinus) and eastern grey kangaroo (Macropus giganteus).
  2. Ritchie, E.G. The socio-ecology of large marsupial herbivores in Australia's tropical savannas.
  3. Ritchie, E.G., Fossan, P.C.K., Martin, J.K. and Johnson, C.N. Sexual segregation in a tropical herbivore, the antilopine wallaroo (Macropus antilopinus).
  4. Ritchie, E.G., Martin J.K. and Johnson C.N. A test of the abundant centre hypothesis across the distribution of a large, tropical herbivore, the antilopine wallaroo (Macropus antilopinus)
  5. Fossan, P.K., Ritchie, E.G., Martin, J.K. & Johnson, C.N. Diet of the antilopine wallaroo (Macropus antilopinus): intraspecific and seasonal patterns.
Conference presentations
  1. Ritchie, E.G., Martin, J.K. and Johnson, C.N. (2007) Interspecific differences in factors influencing the distribution and abundance of two wallaroo species: management implications. Australian Mammal Society Conference, Armidale.
  2. Ritchie, E.G., Martin, J.K., Garnett, S., Krockenberger, A.K. and Johnson, C.N. (2006) An antilopine autecology: distribution, abundance and conservation of Macropus antilopinus. Macropod Symposium, Australian Mammal Society Conference, Melbourne.
  3. Ritchie, E.G. and Bolitho, E.E. (2006) Predictions of the impacts of climate change on large macropods in Northern Australia. Australian Mammal Society Conference, Melbourne.
  4. Ritchie, E.G. (2005) Macropod macroecology: distribution, abundance and conservation of the antilopine wallaroo (Macropus antilopinus). Ecological Society Australia, Brisbane
  5. Ritchie, E.G., Fossan, P.C., Martin, J.K & Johnson, C.N. (2005) Rainfall seasonality, diet and sexual segregation in the antilopine wallaroo (Macropus antilopinus). Ecological Society Australia, Brisbane.
  6. Ritchie, E.G. (2004) Sexual segregation in a tropical macropod (Macropus antilopinus). Australian Mammal Society, Tanunda.
  7. Ritchie, E.G. (2003) Climatic distributions of large macropods in northern Australia. Australian Mammal Society, Sydney.
  8. Ritchie, E.G. (2003) The macroecology and conservation of the antilopine wallaroo (Macropus antilopinus). Australian Mammal Society, Sydney.
  9. Ritchie, E.G. (2003) Sexual segregation in a tropical macropod, the antilopine wallaroo (Macropus antilopinus). Ecological Society Australia, Armidale.
Popular articles
  1. Ritchie, E.G. (2005) Antilopine Wallaroo uncovered. Nature Australia. Summer Issue, 26-31.
  2. Ritchie, E.G. (2004) Unique kangaroo a tropical treasure. Savanna Links, Issue 29.

 

Fig. 1. Map of the study area in northern Australia.

Fig. 2. A map incorporating a BIOCLIM model of the antilopine wallaroo's current distribution.

Fig. 3. Young wallaroo.

Fig.4. Large antilopine male wallaroo in savanna habitat.

Fig.5. Kimberley habitat.

Fig.6. Savanna storm