02 ROYAL ZOOLOGICAL SOCIETY OF NEW SOUTH WALES. 



NOTES ON COLOUR-VARIATIONS OF OPOSSUMS OF THE GENUS TRICHOSURUS. 

 By A. S. LE SOUEF, Director, Zoological Gardens, Sydney. 



The great variation in the colour and markings of the opossums of the genus Trichosurus forwarded 

 to the Zoological Gardens, led me, some years ago, to study them systematically, with a view to 

 determining whether the different forms were confined to definite regions. The following notes are 

 based on the examination of a large series of both specimens and skins, and I have to thank the 

 Curators of the Australian Museum (Sydney), the National Museum (Melbourne), the Adelaide Museum 

 and the West Australian Museum for kind permission to examine skins in their charge. I am also 

 indebted to Mr. H. L. White, of Belltrees, Scone, for forwarding specimens exhibiting colour variation. 



Common Opossum, Trichosurus vulpecula, Kerr. 



The typical form is grey on the upper parts, with a few black-tipped hairs showing through the 

 under-fur and whitish under-parts ; the muzzle, around the eyes, the chin, and the base of the ears 

 are black ; terminal two-thirds of the tail black. The tip of the tail and the posterior distal part 

 of the ears are sometimes white, though both these markings are not necessarily present on the same 

 animal. This form is found in the open forest country throughout Australia, with the exception of 

 the Cape York Peninsula. 



The variations noticed are as follow : — 



(a) A more or less rufous colouration ranging from a slight wasli on the shoulders to an even 

 brown or bright rufous all over the body, in which case the breast may be of a lighter hue 

 or quite white. 



(h) A black colouration produced by a heavy growth of long black-tipped hair coming through 

 the under-fur. 



(c) A fawn colour ranging from even fawn, through yellowish brown to cream. 



As in all marsupials, albinism is fairly common, and albinos generally have white offspring. 



Brown specimens are most common in Tasmania, and Mr. Robert Hall states that they are 

 chiefly confined to the moist, heavily timbered districts. Out of 4,000 skins exported from Tasmania 

 in 1914, 20 per cent, were brown. On the mainland a more or less brown colouration is very common, 

 particularly in the drier districts ; it is more pronounced in Queensland, especially in the north-east, 

 where the form described as Trichosurus johnstonii, Ramsay, was first procured. I have examined 

 the fine series of brown specimens in the Australian Museum, and find great variation, there being 

 intermediate forms from grey-brown to bright rufous with a white breast ; it also includes examples 

 with white-tipped tails and ears, as in the grey form. As the teeth do not show any variation, and 

 as brown specimens are found in other parts of Australia, I consider T. johnstonii is just a local colour 

 variation of T. vulpecula, as has already been recognised by Dr. Ramsay. Fawn-coloured animals 

 have been noted from Central Queensland and at Herberton. 



A black race is found in the heavily-timbered country round the Colley district and Yallingup, 

 West Australia. This colour is caused by a pronounced growth of long silky black hair coming 

 through the grey under-fur, which, on the back, may measure three inches in length ; the breast is 

 whitish or pure white. 



It is interesting to note that the descendants of Tasmanian opossums turned out near Lyttleton, 

 New Zealand, some twenty-five years ago, already show variation from the typical form, in that the 

 black silky hair is much more pronounced ; the animals are thus darker and the fur longer and less 

 dense. 



