An updated description of the Australian dingo ('Canis dingo' Meyer, 1793)

Abstract

A sound understanding of the taxonomy of threatened species is essential for setting conservation priorities and the development of management strategies. Hybridization is a threat to species conservation because it compromises the integrity of unique evolutionary lineages and can impair the ability of conservation managers to identify threatened taxa and achieve conservation targets. Australia's largest land predator, the dingo 'Canis dingo', is a controversial taxon that is threatened by hybridization. Since their arrival <5000 yBP (years Before Present) dingoes have been subject to isolation, leading to them becoming a unique canid. However, the dingo's taxonomic status is clouded by hybridization with modern domesticated dogs and confusion about how to distinguish 'pure' dingoes from dingo-dog hybrids. Confusion exists because there is no description or series of original specimens against which the identities of putative hybrid and 'pure' dingoes can be assessed. Current methods to classify dingoes have poor discriminatory abilities because natural variation within dingoes is poorly understood, and it is unknown if hybridization may have altered the genome of post-19th century reference specimens. Here we provide a description of the dingo based on pre-20th century specimens that are unlikely to have been influenced by hybridization. The dingo differs from the domestic dog by relatively larger palatal width, relatively longer rostrum, relatively shorter skull height and relatively wider top ridge of skull. A sample of 19th century dingo skins we examined suggests that there was considerable variability in the colour of dingoes and included various combinations of yellow, white, ginger and darker variations from tan to black. Although it remains difficult to provide consistent and clear diagnostic features, our study places morphological limits on what can be considered a dingo.