44 Hall, The Plumage Phases of Ptilotis leucotis. [isfjuly 



From a number of skins before me I am able to note seven distinct 

 phases in the plumage development of the species. 



The most important phases, and those which supply new 

 information, are a and b, the skin a being the nestling, with yellow 

 ear coverts, and b an immature bird with ear coverts partly 

 yellow and partly white, in about equal proportions. In another 

 skin the yellow is simply a wash upon a portion of the white, 

 while in a third a flush of yellow is merely visible. In the young* 

 stages the throat is either dull brown or yellowish-brown, or 

 faint yellow with a brown crescent as the indicator of the dark 

 throat, which is brown before the final moult for black. The 

 abdomen also varies between dull tawny and yellow. 



The crown is olive in the early phase, grey and olive in a later 

 moulting stage, and finally grey streaked with black. The 

 dorsal surface is duller in the early stages than in the later, 

 which is in agreement with those of most species of birds. 



Measurements of adult males are supplied as under, to show 

 the amount of variability in the sizes (g 1 , g l ). 



Specimens /; to g, inclusive, show very clearly the maturing 

 of the species as far as its plumage is concerned, for they represent 

 six clear phases. 



Specimens h and ;' show an adult male and an adult female 

 practically to have the same measurements. 



Specimens ; and k show two adult females — one (k) small, 

 and possibly below the average, while the other (;') is about as 

 large as adult females usually are. 



Young birds (as in d) are sometimes larger than adult birds 

 (as in h) of the same sex. The rule, as we have it, is to recognize 

 the male as larger than the female, which is probably correct 

 in a large series of skins. 



Brief descriptions of the important phases are : — 



Specimen a. — Nestling, 31/12/02, Torquay, Victoria. 



In colouration it agrees with b, excepting the ear coverts, which 

 are uniform yellow. Wing, 2.25 inches ; tarsus, 0.85 inch ; 

 culmen, 0.35 inch ; tail, 1.3 inch. 



Specimen /;. — Juvenile, sex not marked, December, 1899, 

 Murray River, Victoria. 



Throat and chest dull olive-brown, remainder of under surface 

 yellowish-olive ; ear coverts, anterior half white, posterior part 

 yellow, and beneath a portion of the white at its base ; head 

 dull yellowish-olive, and slightly duller than the rest of the upper 

 surface; superciliary stripe and lores black. Total length, 

 7 inches ; wing, 3.5 inches ; tarsus, 0.95 inch ; culmen, 0.5 

 inch ; tail, 3.35 inches. 



Specimen c. — Juvenile female, Melbourne, Victoria, 12/4/98. 



* Cat. Birds Brit. Mus., vol. ix., p. 241, has it : — " Young and immature birds have 

 the throat and fore-neck dull brownish-grey instead of black, and the yellow in the 

 plumage is much less developed than in the adult." Nothing is said about ear 

 coverts. 



