Critical-weight-range marsupials in northern Australia are declining: A commentary on Fisher et al. (2014) 'The current decline of tropical marsupials in Australia: Is history repeating?'

Many mammal species are declining in parts of Australia's tropical savannas, for reasons that are not yet well defined. A recent paper (Fisher et al., 2014, Global Ecology and Biogeography, 23, 181-190) suggested that the primary cause is predation by feral cats, with the main evidence presented being a purported over-representation of small species amongst the marsupials that have contracted in range ('small body size signifies high current extinction risk'). However, a review here of the information presented in that paper shows that no marsupial species smaller than 100g has shown range contraction in northern Australia, and that most (15 of 17) declines are of species in the 'critical weight range' (35g to 5.5kg).