The Arnhem Rock-rat is a large (100–150 g) grey rat distinguishable from most other Northern Territory rodents by its large whiskers, typically swollen tail (especially at the base), and the characteristic Roman nose. The tail is up to 15 cm long, and the tip is covered in long hairs. These features are similar to those of the much smaller (30–70 g) Common Rock-rat (Z. argurus), but the species can be can be distinguished by size, colour (the Arnhem Rock-rat is typically more grey than brown), and the higher density of long hairs on the tail (Fleming 1995; Woinarski 2006). Rock-rats have fragile tails and fur, and many individuals may have no or greatly reduced tails, presumably as a consequence of predator attack (Woinarski 2006).
Arnhem Rock-rat, Arnhem Land Rock-rat, Kodjperr |
Zyzomys maini
Status: Vulnerable on the EPBC Act list
Government evidence of impact of climate change:
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Australian Government, Conservation Advice, Zyzomys maini
Threats The main identified threat to the Arnhem Rock rat is inappropriate fire regimes (Woinarski et al.; 2007).
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Australian Government, Listing Advice, Zyzomys maini
Altered fire regimes Arnhem Rock rats are affected both by individual fires and; in particular; the longer term vegetation changes arising from altered fire regimes across the plateau of western Arnhem Land.
A study on the effect of fires on small mammals in monsoon rainforest in the sandstone plateau of western Arnhem Land indicated small mammals were clearly affected by fire; with results showing that after fire the numbers of animals alive were lower; reproductive output and pattern changed and habitat use changed.
The threatening process of changed fire regimes on the sandstone plateau of western Arnhem Land is likely to be leading to declines in numbers and habitat quality of the Arnhem Rock rat across its entire range; and there is quantitative data to support that declines have occurred in three study areas over the last 10 20 years.
As discussed in criterion 1; the threatening process of changed fire regimes on the sandstone plateau of western Arnhem Land is likely to be causing continuing declines in numbers and habitat quality of the Arnhem Rock rat.
As discussed in criterion 1; the threatening process of changed fire regimes on the sandstone plateau of western Arnhem Land is likely to be causing continuing declines in numbers and habitat quality of the Arnhem Rock rat.
Within its habitat; there are a number of threatening processes operating; however; it is the change from the traditional fire regime of low intensity fires to the current fire regime of more frequent and more intense fires that is likely to be adversely affecting this species across its range; with three places on the plateau recording declines in numbers of individuals.
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