350 Dr. A. G. Butler on 



XXXVITI. — Notes on the Satin Bower-hird (Ptlloiiorliynclms 

 violaceus). By Arthur G. Butler, Ph.D., F.L.S., 

 F.Z.S., &c. 



In a paper which I published in the 'Zoologist' for July, 

 1902, p. 257, I called attention to a statement made by 

 Mr. A. A. C. Le Souef, Director of the Zoological Gardens 

 at Melbourne, and stated that the idea that the males of this 

 species only assumed their full pluma.^e in old age was con- 

 trary to all our experience of bird-life ; and on pp. 2.51, 252, 

 I suggested that the birds studied by Mr. Le Souef were not 

 cocks, but old hens which had assumed male plumage owing 

 to abortion of the functional ovary, a circumstance not 

 uncommon in birds in captivity, and possibly less so than in 

 wild birds. 



Mr. Le SouePs statement is as follows {vide Campbell's 

 * Nests and Eggs of Australian Birds/ p. 192, footnote) : — 

 *' Many years ago I caged a number (at least a dozen) of these 

 birds at the gardens here, young green birds, caught at 

 Gembrook, and it was only after the expiration of nearly 

 eiyht years they began to change colour. I think four or five 

 birds put on the beautiful blue-black plumage, and in a year 

 or two died off. It is therefore evident that the birds only 

 come to their full plumage in old age, and that accounts for 

 the fact that in a flock of say one hundred birds, which we 

 often used to see at Gembrook, some years ago, there would 

 be only a very few, not half a dozen, black ones among them. 

 They die off shortly after the change.-" 



It is well known that during certain months of the year 

 many birds travel about in flocks consisting wholly of one 

 sex, which would explain the occurrence of only six per cent, 

 liens in male plumage in a flock, without the necessity for 

 arriving at so improbable a conclusion as that the male of 

 this species (unlike all others) assumed its attractive plumage 

 towards the end of its life. 



My own experience of Ptilonorhynchus is directly opposed 

 to Mr. Le Sonet's view: — On September 18tli, 1899, I 

 purchased a pair of young Satin Bower-birds in the spotted 

 green plumage, which vaguely resembles the adult hen 

 plumage (only the latter is not of the same pale-spotted 

 character). By the end of the following September (1900) 

 both sexes had attained their full adult plumage — the male 

 blue-black, the female olive-green, cinnamon, and yellow ; 

 both sexes with brilliant ultramarine eyes. 



The late Mr. Abrahams was of opinion that this species 

 assumed its full plumage when three years old ; but judging 



