Too hot for the devil? Did climate change cause the mid‐Holocene extinction of the Tasmanian devil Sarcophilus harrisii from mainland Australia?

Abstract

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.