SOME RESULTS OF OSTRICH INVESTIGATIONS. 259 



The Northern Ostrich. — North African chicks are a bright 

 deep yellow, almost orange, over the legs and head, and a slightly 

 paler yellow over the body and neck. As maturity is reached 

 the hen becomes a light yellow, the tarsal scales assuming a light 

 or dark horny brown. Some northern hens are slightly pink over 

 parts of the body, and sometimes it may show through the white 

 downy covering of the neck. 



The North African cock undergoes certain remarkable colour 

 changes as sexual maturity is attained, which are a sure guide to 

 the farmer as to the breeding condition of the bird. The deep 

 yellow of the chick is gradually replaced by a light yellow, this 

 by pink, and then b^' red, reaching a bright scarlet over the legs, 

 body neck and head as the actual mating period is reached. The 

 bright scarlet colour contrasts strongly with the jet black body- 

 "feathers, white waving wings, erect light brown tail feathers and 

 fleecy white down of the neck, and makes of him a glorious 

 creature as he prances about in his breeding camp in all the pride 

 and pugnacity of his sex. The nu])tial colours pale greatly when 

 nesting begins, and also when the breeding season is over, the 

 body being reduced to a pale pink or brick colour. At its height 

 so 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. — South African chicks are at first 

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

 Cape chicks may show a rich deep yellow around 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 around 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 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 around the eyes assimxe the bright 

 scarlet vvhichi characterises practically the entire body of the 

 northern bird. 



In southern cocks the red colour of the northern would 

 appear t'- be latent or perhaps wholly obscured by the dark blue. 



