James Cook University, Townsville
Aims and outcomes | Tropical kangaroo | Wallaroo
populations in Queensland | Intensification of cattle grazing |
Property planning in Cape York | Mammal decline in northern Australia | Rapid
decline in north | Supervisors | References |
The antilopine wallaroo—surveys have shown
numbers are declining in Cape York
The principal aim of this study is to determine the current
population status and document the ecology of the antilopine
wallaroo ( Macropu antilopinus ) within its Queensland
distribution. Recent surveys and research has shown that the
wallaroo may be in decline, and has been identified in this way by
the Queensland Parks & Wildlife Service. The range of the
species in Queensland is restricted and patchy, which means the
animal could quickly become rare and threatened if observed trends
continue, facilitating a need for proactive management.
This study will provide essential information on habitat
requirements that will underpin the wallaroo’s management.
Further, by identifying possible causes of decline, the study will
produce specific recommendations on the changes in land management
needed to prevent further declines. Conservation of the species
will ultimately depend on appropriate management of cattle grazing
properties, the dominant land use throughout its range.
The antilopine wallaroo ( Macropus antilopinus ) is
Australia’s only kangaroo species restricted entirely to the
tropics, making it both a high conservation priority and
interesting study subject. The species also has the potential to
assist in the sustainable use of tropical savannas through a
commercial and/or indigenous harvest and ecotourism.
At present two geographically separate populations are
recognized: one on the Cape York Peninsula (CYP), and the other in
the Top End of the Northern Territory (Strahan, 1995). The ecology
of the wallaroo is poorly known with only a few minor field studies
conducted in the Northern Territory (Russell and Richardson, 1971;
Croft, 1982 & Croft, 1987). No systematic, detailed research
exists on the species within its Queensland range.
This project will make an intensive systematic study at a local
scale and broad-scale surveys throughout Cape York Peninsula.
Observations in the vast wilderness area of Cape York Peninsula,
has shown widespread mammal declines (Christopher Johnson, Peter
Johnson & John Winter, pers. comm., 2002). The Cape is
approximately 13.5 million hectares in size and encompasses a
diverse assemblage of habitats and associated flora and fauna.
Mammal species recorded as declining include the black footed
tree rat ( Mesembriomys gouldii ), northern quoll (
Dasyurus hallucatus ), common brushtail possum (
Trichosurus vulpecula ), rufous bettong ( Aepyprymnus
rufescens ), some rock wallabies ( Petrogale spp.) and
the antilopine wallaroo ( Macropus antilopinus ) (John
Winter, Christopher Johnson & Peter Johnson, pers. comm.,
Of the six living species of kangaroos (mean adult body weight
more than 20 kg) none have been listed as endangered (Dawson, 1995)
and the reported reduction in abundance of the antilopine wallaroo
may represent the first observed decline of a kangaroo since
Typically kangaroos have prospered as a result of the
land-management practices associated with livestock grazing; the
establishment of permanent water sources, clearing of woodland in
favour of grasslands and the removal of predators, particularly
Large reductions in the abundance of the antilopine wallaroo
have been noted in the southern parts of its Queensland range,
where the species was abundant in the early 1980s but is now
apparently relatively scarce (Peter Johnson, pers. comm).
This reported decline occurred at the same time as an
intensification of cattle grazing throughout areas of north
Queensland in the 1970s and 1980s, leading to the establishment of
Brahman ( Bos indicus ) breeds of cattle and the widespread
provision of nutrient supplements for cattle.
The association between an intensification of cattle grazing and
a reduction in M. antilopinus abundance may indicate this
macropod is sensitive to habitat changes related with the
introduction of livestock. This relationship contrasts with other
kangaroo species (e.g. Macropus rufus, Macropus giganteus ),
which have typically flourished on cattle properties.
Wallaroos drinking at a dam
Cooperative management of the resources of CYP, as envisaged in
the Cape York Natural Heritage Trust Plan, is to be based on
property planning that takes into account the goals of commercial
utilisation (primarily for cattle grazing), indigenous rights and
nature conservation. This study will provide the basic information
needed to incorporate appropriate management of the habitat of the
antilopine wallaroo into property planning on the Cape.
Given that the antilopine wallaroo is harvested as a bush food
by Aboriginal communities, our estimates of population size,
distribution and reproductive rates will allow us to estimate
sustainable harvest rates. The study will also result in a better
understanding of recent ecological changes on Cape York Peninsula,
and their effects on wildlife.
C. Johnson, JCU
A. Krockenberger, JCU
J. Woinarski, NT DIPE
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