166 Crossing the North and South African Ostrich 



sensitive is the colour to the physiological state of the bird that close 

 observation often reveals variations in the intensity within the same 

 day, as well as from day to day. 



The Southern Ostrich. The skin of South African chicks is at first 

 pale yellow in colour and afterwards dark grey. Highly fed Cape 

 chicks may show a rich deep yellow round the eyes and beak, though 

 this does not continue for more than a few months. Mature southern 

 hens are a dark grey over the legs, body, neck and tarsal scales. 



The Cape cock is at first a dark grey or steel colour, much like the 

 hen, but as sexual maturity is gained he assumes a fresh, bright blue 

 over the greater part of the body, while the tarsal scales, beak and naked 

 parts round the eyes become a bright scarlet ; the small scales over the 

 sides and hind part of the tarsus may also be red or pink, but ordinarily 

 none of the red colouration extends beyond the tarsus, nor over the body 

 and neck. 



Thus northern chicks are a deeper yellow than southern chicks. 

 They pass to a pale yellow and the hen remains at this stage, but the 

 cock passes beyond to a pink and then a scarlet stage. The pale yellow 

 of southern chicks is early replaced by a dark grey which persists in the 

 hen, but is followed in the cock by a blue or blue grey as sexual maturity 

 is reached ; moreover, only the tarsal scales, beak, and skin round the 

 eyes assume the bright scarlet which characterises practically the entire 

 body of the northern bird. 



In southern cocks the red colour of the northern would appear to be 

 latent, or perhaps wholly obscured by the dark blue; for on recovering 

 from an injury to the neck or body it is often found that the scar of the 

 new skin shows a reddish tinge. 



Cross-bred Ostriches. The colour of the skin of cross-bred chicks is 

 intermediate between that of northern and southern chicks. The legs, 

 body and large scales are a pale yellow, which is lighter than that of 

 Cape chicks but never so deep as that of Nigerian chicks. The adult 

 cross-bred hen retains the light yellow body colour, though usually it 

 becomes a little darker compared with the chick. The colour remains 

 darker than that of the pure northern hen, but is invariably lighter than 

 the pure Cape. 



The cross-bred cock retains the uniform light yellow of the hen 

 until sexual maturity approaches. He then assumes a pink tinge in 

 places and later the bright scarlet. As noted, however, it is in the 



