Notes on Plumage Changes. 19 



Pachycephala gutturalis, Latham. 



■A glance at the specimens exhibited in support of this species 

 shows three distinct colour ])hases ; the young being uniform 

 T'usty-brown, the intermediate stage varying grey and brown, the 

 adult phase jonquil-yellow, black and white. Six phases clearly 

 show the development towards a seventh or mature stage. A, B, 

 C, E and F demonstrate steps in the growth of the male, while D 

 shows a stage of the female immediately after C, when the male 

 "yellows" fail to appear, and the stage progresses no further. 

 In outward material this is where the female is first and always 

 recognised. It is at this stage that the last of the rusty brown 

 feathers of early age drop out and, if a female, they are simply 

 I'eplaced by "greys," but if a male, a few "yellows" appear. 

 This is where the index of sex is first shown externally, though 

 feebly. 



While both sexes are in the nest, they are rufous. Upon 

 leaving the nest, a few light brown feathers mix, and these 

 remain for some time. In early spring of the following year the 

 rusty coloured secondaries are all that remain of the brown phase. 

 Following this stage, if the bird is to prove itself a male, a slight 

 indication of "yellow" will appear somewhere in the regions of 

 yellow. Being now spring, the bird, in my opinion, will, in rare 

 cases, breed in this far from nuptial plumage, but, as a rule, it 

 will hold over this part of its career until the following season. 

 As in many other Australian birds, I take phase E^ to be a 

 precocious male breeding, but not in breeding plumage, showing 

 only the faintest external indication of its sex, but strongly 

 developed internal organs. This bird was perched close to a 

 nest of eggs, and was delivering a pleasant strain, much as an 

 adult would do. Phase F is the connecting link of the adult and 

 junior stages. A few black feathers of the head and pectoral 

 collar are first to appear, while one or two "yellows" below the 

 breast help to indicate the sex. There is yet no indication below 

 the plumage of the mass of yellows. Probably they will come 

 with the throat " whites," of which there is no sign just now. 

 Being August 25, I am strongly disposed to believe no develop- 

 ment into full livery will come into effect until early next spring. 

 The state of plumage of this specimen is specially interesting. 



2a 



