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We use fossil, sub‐fossil and contemporary records of the Broad‐toothed rat, Mastacomys fuscus, to model changes in its range over the last 21 thousand years. Mastacomys fuscus was exposed to, and flourished in, a much broader range of environmental conditions in the recent past than it occupies today. It also currently occupies a much smaller range than it did in the Late Pleistocene. Apart from a weak response to sea‐level rise in the Holocene, the decline of M. fuscus does not correlate with known climate change. Instead, the contraction of the species' distribution on mainland Australia to high‐elevation areas occurred recently and rapidly. Small changes in the 1000 year BP and present‐day projected distributions imply some contraction of the area of suitable climate to higher elevations of the mainland subspecies M. f. mordicus, up to 2200 m above sea level. However, M. f. mordicus also persists near sea level at Cape Otway (southwestern Victoria) and from sea level to 1500 m above sea level at Barrington Tops (eastern New South Wales, Australia). This suggests suitable habitat may still exist in coastal Victoria and the central Tablelands/Blue Mountains areas. This research highlights the importance and value of using sub‐fossil data to understand changes in the distribution and niche occupation of threatened species as the basis for conservation planning. [ABSTRACT FROM AUTHOR]

The possible role of climate change in late Quaternary animal extinctions is hotly debated, yet few studies have investigated its direct effects on animal physiology to assess whether past climate changes might have had significant impacts on now‐extinct species. Here we test whether climate change could have imposed physiological stress on the Tasmanian devil Sarcophilus harrisii during the mid‐Holocene, when the species went extinct on mainland Australia. Physiological values for the devil were quantified using mechanistic niche models of energy and water requirements for thermoregulation, and soil‐moisture‐based indices of plant stress from drought to indirectly represent food and water availability. The spatial pervasiveness, extremity and frequency of physiological stresses were compared between a period of known climatic and presumed demographic stability (8000–6010 BP) and the extinction period (5000–3010 BP). We found no evidence of widespread negative effects of climate on physiological parameters for the devil on the mainland during its extinction window. This leaves cultural and demographic changes in the human population or competition from the dingo Canis dingo as the main contending hypotheses to explain mainland loss of the devil in the mid‐Holocene. [ABSTRACT FROM AUTHOR]