Casoar de la Nouvelle Hollande Péron, Relat. Voy. Terr. Austr. I p. 467, pl. XXXVI (1807).
Dromoius ater Vieillot, Gal. des Ois, pl. 226 (not text).
Dromaeus ater Blyth, Ibis 1862, p. 93.
It is most unfortunate that the larger number of authors have neglected to go carefully into the synonymy of this bird; if they had done so it would not have been necessary, after 81 years, to reject the very appropriate name of ater, and to rename the Emu of Kangaroo Island. Vieillot, in the Nouveau Dictionnaire D'Histoire Naturelle X, page 212, distinctly states that his Dromaius ater was a name given to Latham's Casuarius novaehollandiae, and makes no mention of Péron or of the Isle Decrès.
The figures in Péron's work of the adult male and female are not good, but those of the young and nestlings appear to me to be very accurate, and the plate in the Galérie des Oiseaux is quite excellent. The latter and my own are taken from the type specimen in the Paris Museum, while the plate in Péron was done by Lessieur from a series of sketches from life made by himself on Decrès Island and in the menagerie of the Jardin des Plantes. The only known specimens of this extinct species are the mounted skin and skeleton in Paris and the skeleton in the Florence Museum. All these are what remain of the three living birds brought to Paris by Péron, and no other authentic specimens exist anywhere. There is in the Museum at Liverpool a full-grown, though immature Emu of the same size as Dromaius peronii, but owing to its proportionally longer legs and very scanty plumage it is not absolutely safe to identify it as a second mounted specimen of D. peronii. I will recur to this lower down.
Description of adult male (ex Cat. Birds Brit. Mus.): Similar to D. novaehollandiae, but much smaller, and with feathers of the neck entirely black; feathers of the body brown fulvous, with the apical half very dark blackish brown; bill and feet blackish, naked skin of the sides of the neck blue. Total length about 55 inches, tarsus 11.40, culmen 2.36.
Immature in first plumage entirely sooty black. Nestling whitish with longitudinal bands of rufous brown. In addition to Decrès or Kangaroo Island, also Flinders, King Islands, and Tasmania had Emus living on them
at the time of Péron's visit, and I believe, if authentic specimens from these localities were in existence we should find that each of these islands had had a distinct species or race of Emus. Taking this for granted, and also taking into account that it is slightly different from the type of D. peronii, I have come to the conclusion that the Liverpool specimen is an immature, though full-grown individual from one of these other islands; but it is not possible from this one rather poor specimen to separate it from the Kangaroo Island species, especially as there is absolutely no indication of the origin of this specimen.
Habitat: Island of Decrès or Kangaroo Island.
One stuffed specimen (Type) and one skeleton in Paris, one skeleton in Florence, and one stuffed specimen in Liverpool (an species diversa?). Also some leg-bones in Adelaide, Australia.
Dr. H. O. Forbes, who kindly lent me the last-named specimen, was the first to point out the differences of this bird from D. novaehollandiae. It is certainly totally distinct from birds of similar age of either D. novaehollandiae or D. n. irroratus.