Context: The pale field-rat (Rattus tunneyi) is a small native rat that formerly had a wide distribution throughout Australia. It has suffered substantial range contraction since European settlement and is now largely absent from arid and semiarid Australia. In this biome, it was known to persist only at two Western Australian locations: Edel Land, on the south-western shore of Shark Bay, and islands off the Pilbara coast.

Aims: We aimed to establish the extent of the species range at Edel Land, its habitat preference, the temporal stability of its populations with respect to rainfall, and threats to its persistence.

Methods: We trapped at 54 sites to establish distribution and habitat preference, and re-trapped four of these sites at which R. tunneyi was present in each season for 2.5 years to establish trends in abundance.

Key results: Trapping resulted in the capture of 45 R. tunneyi individuals across 17 of 54 sites (4104 trap-nights; 1.1% capture success). Rattus tunneyi typically occupied localised areas of dense shrubland, often in habitats with free water or near-surface moisture from drainage from high dunes allowing denser and taller vegetation and, at some sites, year-round growth of grasses or rushes. Regular re-trapping of four sites in each season (2002 – 2004) suggested a declining population, probably owing to a sequence of dry years.

Key conclusions: Rattus tunneyi at Shark Bay occurred only in localised mesic refuges, apparently dependent on seepage from high dunes generated by major inputs of rainfall from infrequent cyclones or sequences of high-rainfall years.

Implications: This isolated population is likely to be threatened by browsing by feral goats, opening up otherwise densely vegetated habitats of refuge areas, and their trampling of R. tunneyi burrows; by the depletion of grasses from herbivory by European rabbits; and by the long-term impact of a drying climate. It is unlikely to persist without effective on-going management, particularly of the goat population.

背景：苍白地鼠（Rattus tunneyi）是一只小型本地老鼠，以前曾在整个澳大利亚分布很广。自欧洲定居以来，它遭受了范围广泛的收缩，而现在干旱和半干旱的澳大利亚基本上不存在它。在这个生物群落中，已知它只能在澳大利亚西部的两个地方存在：鲨鱼湾西南海岸的埃德尔·兰德（Edel Land）和皮尔巴拉海岸附近的岛屿。

目的：我们的目标是确定埃德尔土地的物种范围，其栖息地偏好，其人口在降雨方面的时间稳定性以及对其持久性的威胁。

方法：我们诱捕了54个地点以建立分布和生境偏好，并重新诱捕了其中4个在每个季节都存在金枪鱼2 .5年的地点，以建立丰度趋势。

关键结果：诱捕导致在54个站点中的17个站点中捕获了45个通气的通气衣藻（4104个陷阱之夜；捕获成功率为1.1％）。褐家鼠通常居住在茂密的灌木丛的局部区域，通常栖息在高水沙丘排水而释放出自由水或近地表水分的栖息地中，从而允许种植密度更高和更高的植被，在某些地方还可以全年生长草皮或草丛。每个季节（2002年至2004年）定期重新诱捕四个地点表明人口减少，这可能是由于干旱年份造成的。

主要结论：鲨鱼湾的褐家鼠仅在局部的中性避难所中发生，显然取决于不频繁的旋风或高降雨年份序列的主要降雨产生的高沙丘的渗漏。

启示：野山羊浏览，开辟原本茂密的避难所栖息地，以及践踏通尼罗非鱼（R. tunneyi）洞穴，可能会威胁到这种孤立的种群。欧洲兔子吃掉了草食性草；以及干旱气候的长期影响。没有有效的持续管理，尤其是山羊种群的持续管理，就不可能持续下去。