566 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



toward its extremity. It may then be extracted without injury to 

 the bird. The plumes are clipped before the lower part of the quill 

 is ripened, otherwise their tips would be much worn, and the feather 

 as a whole greatly depreciated in value; this applies also to all the 

 later feather crops. As the severance takes place through the upper 

 ripened part, above the blood in the pith, there is no hemorrhage, 

 which should be avoided for the sake of the later feather. 



As regards the feathers of the chick plumage there is no reliable 

 sexual difference in the ostrich, nothing to indicate which are cocks 

 or hens, a matter often of much importance to the farmer. Usually, 

 however, the spadonas from cock chicks are lighter than those from 

 the hens. To determine the sex with certainty, however, other char- 

 acters are available at this time. 



The wing plumes being clipped at about 6 months, the tail quills 

 and two rows of wing coverts are allowed to ripen, and are plucked 

 at from 7 to 8 months; being of little value they are rarely clipped. 

 All the other feathers of the chick plumage are allowed to follow 

 the natural method of molting. The process is carried out at very 

 different times in different parts of the bird and will be described in 

 connection with the juvenal plumage. 



From 5 to 6 months onward the chick plumage as a whole begins 

 to lose its primary characteristics. Many of the body feathers are 

 early pushed out by those of the juvenal plumage, and, as the latter 

 are larger and uniformly steel gray, they show conspicuously among 

 the mottled chick plumes. The chick feathers drop out first in the 

 hip region by the time the chick is 5 months old, that is. before some 

 of the other feathers of the plumage are fully grown. The chick 

 feathers which are not replaced begin to lose their freshness of color 

 from about 6 months onward, the lighter brown at the end of the 

 feathers especially disappearing. In the wear and tear the tips are 

 general^ worn away, and the adhering natal feather is broken off. 



The general color effect of the chick ostrich, in both the natal and 

 chick stages (pi. 1, fig. 2, pi. 2, fig. 1), would appear to have a protec- 

 tive significance, the light and dark mottlings closely resembling the 

 dry veld or grass on which the chicks usually crouch in nature. When 

 at all alarmed, chicks suddenly scatter and then drop flat on the 

 ground, with the neck and head extended, exhibiting death feigning 

 to a greater or less degree, and in this condition all farmers have 

 noted the difficulty in recognizing the chicks on account of the close 

 resemblance which they bear to their surroundings. 



THE JUVENAL PLUMAGE. 



The third or juvenal plumage represents an intermediate stage 

 betwen the chick and the adult plumage. It does not, however, fol- 

 low immediately upon the second or chick plumage, as molting is 



