SILVERBILL 159 



sumably females or young) were met with almost 

 every day for nine weeks, and frequently in large 

 numbers. Of course I began to suspect that the 

 males must moult into a brown suit after nesting, as 

 do our Bobolinks and many other birds, but I shot 

 specimens at various times, and all proved to be 

 either females or young males, and as I was confident 

 that at Concepcion black males were to be found 

 through the year, I was at a loss for an explanation, 

 and am so still/' 



The male Silverbill is entirely black, there is 

 nothing in nature blacker than its plumage ; and, to 

 enhance the effect, the beak is of a very delicate 

 primrose-yellow, which at a little distance appears 

 white, hence the vernacular name. The eye, and 

 broad free skin surrounding it, which is ruffed like 

 an Elizabethan collar, are of the same faint primrose 

 hue. The secondary wing-quills are pure white, but 

 the white is only displayed when the bird flies. The 

 female has the naked skin encircling the eye, but its 

 colour, as also that of the beak, is much darker than 

 in the male. Entire upper plumage dark brown ; 

 secondaries chestnut ; lower parts fawn-colour, 

 marked with brown. The young males are at first 

 like the females in colour, and do not acquire the 

 black plumage until the end of the summer. 



The bird ranges over the whole of the Argentine 

 Republic, and, according to Gay, is also common 

 throughout Chili, where it is known as the Colegial 

 (Collegian or learned person), on account of its stiff 

 grave manner, black dress, and spectacled appearance. 



