162 Crossing the North and South African Ostrich 



Dimensions. 



On account of its restless nervous nature and the difficulty of fixing 

 upon constant determinable points the live ostrich is not a creature 

 which lends itself to accurate bodily measurements. In any troop it 

 will be found that the members differ much among themselves, and the 

 same individual varies at different ages and according to its nutritive 

 condition. Hence the northern and southern birds and the crosses from 

 them can be compared only in general terms, as when seen side by side. 

 The average North African ostrich is a much taller bird than the South 

 African, being longer in the legs and neck. The head reaches to a 

 height of from eight to nine feet from the ground whereas in the Cape 

 bird it extends only seven to eight feet. The feet, legs and neck of the 

 Nigerian bird are also more robust. The general dimensions of the 

 body do not differ much in the two, the greater size of the northern 

 being mainly a result of the longer legs and neck. As a chick and 

 young bird the body of the northern ostrich however tends to narrow 

 behind more than the southern, but later this becomes a feature largely 

 dependent upon the nutritive state. The relative sizes admit of the 

 two being easily picked out in a mixed troop, the heads of the northern 

 birds towering a foot or so above those of the southern. 



The cross-bred birds at maturity stand higher than pure Cape birds, 

 but are not so high as the Nigerian. As chicks the body tends to 

 narrow behind more than in Cape chicks, so that, with the slightly 

 longer legs and tapering body, they appear decidedly more slender than 

 Cape chicks of the same age. On the whole it can be said that as 

 regards size, especially length of limbs and neck, the hybrids follow 

 neither one parent nor the other but are intermediate between the two, 

 though the statement is not one which can be supported by actual 

 measurements. 



The two chicks of the second cross-bred generation already reared 

 are now a year old and as regards their general size are strikingly like 

 the South African grandparents as contrasted with the North African, 

 including the shorter, less robust legs and neck. When mingling with 

 first generation cross-breds of the same age the difference is most 

 marked, and no one would hesitate in regarding them as pure Cape 

 birds. Such a result is at least suggestive that the distinctive sizes of 

 the northern and southern ostrich will undergo segregation in the F2 

 generation, but further chicks will be necessary before the real nature 

 of the segregation can be determined. 



