Threatened Species of the Northern Territory PALE FIELD-RAT Rattus tunneyi Conservation status Australia: Not listed Northern Territory: Vulnerable Photo: K.Brennan Description Conservation reserves where reported: Barranyi (North Island) National Park, Black The pale field-rat is a medium sized rodent Jungle Conservation Reserve, Blackmore whose coat is rough but shiny, pale brown River Conservation Reserve, Charles Darwin above grading through yellowish-grey to National Park, Connells Lagoon Conservation cream below. The tail is shorter than head- Reserve, Elsey National Park, Giwinning / body length with dark scale rings. The eyes Flora River Nature Park, Garig Gunak Barlu are large and protruding, the ears pale brown National Park, Judbarra / Gregory National and the feet are white above. The head is Park, Kakadu National Park, Keep River broad and rounded. National Park, Limmen National Park, Litchfield National Park, Manton Dam Distribution Recreation Area, Mary River National Park, Found in the higher rainfall areas of northern Territory Wildlife Park/Berry Springs Nature Australia, extending from the Kimberley to Park, Tjuwaliyn (Douglas) Hot Springs Park south-eastern Queensland. Including the Top and Uluru-Kata Tjuta National Park. End of the Northern Territory (NT). Formerly the range extended into arid and semi-arid area and temperate south-western Australia but retracted into higher rainfall areas in the north (Braithwaite and Griffths 1996). Pale field-rats have been recorded from only a few islands in the NT and recent analysis suggests that they have disappeared from Centre, West, and South West Islands in the Sir Edward Pellew group over the period 1966- 2009, with this decline mostly in the period subsequent to 1988 (Woinarski et al. 2011). Known locations of the pale field-rat For more information visit www.denr.nt.gov.au Ecology Conservation objectives and management It was once a widespread species found in dense vegetation along creeks. The pale field There is no existing recovery plan or rat is nocturnal, sheltering in extensive management program for this species. shallow burrows during the day. Pale field- rats form loose colonies. Food consists of In the interim, priorities for the recovery of roots, grass stems and seeds. In the NT this species are to: breeding occurs during the dry season. Litter i. conduct research to define cause(s) of size is 2-11, although usually four, and several decline; and litters may be raised in a year. ii. continue long-term survey programs in Kakadu, Litchfield and Nitmiluk Conservation assessment National Parks to monitor distribution The pale field-rat is one of a suite of mammal and abundance. species that have considerably declined Complied by across the Top End of the NT over the past ten years, with no clear explanation. On-going Stuart Young monitoring in three national parks have Brydie Hill recorded significant declines of pale field rat, [updated December 2012] including Kakadu National Park a former stronghold for the species (Woinarski et al References 2010). Although the species does appear to Braithwaite, R. W., and Griffiths, A. D. (1996). The exhibit some substantial dynamism in paradox of Rattus tunneyi: endangerment of a numbers (Woinarski et al 2004) the on-going native pest. Wildlife Research 23, 1-21. downward trend is of concern. Woinarski, J.C.Z., Milne, D.J., and Wanganeen, G. (2001). Changes in mammal populations in This species qualifies as Vulnerable in the NT relatively intact landscapes of Kakadu National (under criterion A2abc), based on: Park, Northern Territory, Australia. Austral • Population reduction of >30 per cent Ecology 26, 360-370. over the last ten years; based on direct Woinarski, J.C.Z., Armstrong, M., Price, O., McCartney, J., Griffiths, T., and Fisher, A. observation, an index of abundance (2004). The terrestrial vertebrate fauna of appropriate to the taxon and declines Litchfield National Park, Northern Territory: in area of occupancy and extent of monitoring over a 6-year period, and response occurrence. to fire history. Wildlife Research 31, 1-10. Woinarski, J.C.Z., Armstrong, M., Brennan, K., Fisher, A., Griffiths, A.D., Hill, B., Milne, D.J., Threatening processes Palmer, C., Ward, S., Watson, M., Winderlich, S., and Young, S. (2010). Monitoring indicates rapid No single factor has been demonstrated to and severe decline of native small mammals in have caused the decline of pale field-rat. The Kakadu National Park, northern Australia. current Territory wide decline is probably due Wildlife Research 37, 116-126. to ongoing inappropriate fire regimes (too Woinarski, J.C.Z., Ward, S., Mahney, T., Bradley, J., frequent) affecting habitat suitability, and Brennan, K., Ziembicki, M, and Fisher, A. (2011). predation by feral cats. The mammal fauna of the Sir Edward Pellew Islands, Northern Territory, Australia: refuge and death-trap. Page 2 of 2 .