i^y Mr. A. Duncan on the 



plain brown. I have for some time had these birds under close 

 observation in captivity with a view of following the exact 

 course of the changes of plumage which occur. I may state 

 that my aviary is eighteen feet long, eight feet wide, and 

 eight feet high : one half is roofed in, and the other covered 

 w^ith wire netting : the floor is the natural soil, in which is 

 placed a cement bath : the cage contains two trees and 

 plenty of reeds. 



Under these conditions I have found that these birds 

 thrive well. 



In their winter plumage of plain unattractive brown there 

 is little noticeable except that the centres of the feathers are 

 darker than the edges. The two sexes are then so much alike 

 as to render them almost indistinguishable : oryx com- 

 pletely throws off its summer tints, taha retains its yellow 

 tail-coverts and capensis its yellow rump. 



In their wild state September is their moulting month, 

 but, for some reason which, I presume, may be due to their 

 state of captivity, the first signs of change of plumage do 

 not take place in my aviary until October. 



In the male the first indication of moult is shown by the 

 appearance of a few black feathers at the base of the upper 

 mandible, but, after this first alteration, there is no definite 

 rule — some assuming the feathers of the head first, others of 

 the back or breast, and others their tail-coverts. 



In this moult they change their feathers and colour with 

 the exception of the wings and tail. The bill becomes jet- 

 black, whilst the legs retain the horn-colour of the winter 

 dress. With the change of plumage the character of the 

 birds alters considerably. Many of the feathers are erected 

 at will, the effect being to impart a depth and intensity of 

 tone to the colour of which the preserved skin gives but a 

 poor idea. 



On/.r in its summer plumage of scarlet and black becomes 

 extremely pugnacious and amatory, each bird selecting, as a 

 rule, a particular perching place, from which it endeavours 

 to drive any intruder, particularly of its own species. It 

 menaces any trespasser with every feather erect and shrill 



