256 A HISTORY OF BIRDS 



Apteryx, it may be mentioned, has a uniform grey colora- 

 tion. 



There is no reason to believe that the Grebes are even re- 

 motely related to the Ostriches, yet the nestlings of these birds 

 display a precisely similar style of coloration — light longitudinal ' 

 stripes on a dark ground. 



It is interesting to note that while in the nestling plumage 

 of the " Ratite" birds and the Grebes we find a relatively large 

 number of stripes, in all the forms now to be considered the 

 pattern is almost invariably formed by a median and two lateral 

 stripes. In some species these stripes are strongly marked, in 

 others barely traceable. 



But great variability in this matter obtains, even among the 

 several species of a single family. In the Tinamous, for example, 

 a median stripe along the back, extending forwards up the neck 

 on to the head, and a dark stripe behind the eye, occurs with 

 some frequency. Others of this group are uniformly coloured, 

 or have a dark occipital patch {NotJiocerais). In Rhvnchotus 

 the head and neck are spotted, as in the nestlings of the 

 Ostriches. 



The Game-birds are undoubtedly, as a group, striped when 

 nestlings, though in many this striping is giving way to mottling 

 by the breaking up of the stripes. 



The nestling Curassow, e.g., Crax alcctor, is conspicuously 

 banded. The mid-dorsal line is marked with a broad chest- 

 nut band, bounded on either side by a conspicuous white 

 stripe, the band commencing on the head and widening back- 

 wards. The white bars also commence on the head. Again, 

 in the young Argus Pheasant we have a similar dark median 

 band bounded by white stripes. In the young Blackcock 

 {Lyrurus tetrix) the general ground colour is buff, the back of 

 the neck bears a median stripe which bifurcates at the trunk to 

 run down on either side of the middle line in the form of two 

 indistinct lines. The occiput and the rump are of a warm 

 chestnut colour. But the general effect of this pattern is 

 mottled rather than striped. This mottling is more pronounced 

 • in the Capercailzie nestlings, and in those of the Pheasant and 

 Partridge ; probably this mottling is derived from the breaking 

 up of stripes, the last phase of the striped dress being seen in 

 the nestling Red Grouse. 



