WING-CLAWS FOR CLIMBING 133 



use in a modern bird, if only during youth, for as 

 the bird gets older and fledges, which it does in 

 the usual uniform way, the claws are shed. This is 

 curious, because in the Ostrich, which is ages away 

 from any perching or climbing ancestor, being not 

 only flightless but having lost not only the gripping 

 hind toe but also the one next to it, the wing- 

 claws are retained throughout life. 



The peculiarity of the young Hoatzin is not so 

 unique as might appear, for the young of the 

 Tpuracous (Musophagidtz), with which it used 

 formerly to be classed, also pull themselves about 

 their nests with their wings, as was first pointed 

 out by Sir Harry Johnston, and confirmed by Mrs. 

 Johnstone from observation on a specimen bred in 

 her aviary. 



Young Moorhens and Porphyrios also use their 

 downy wings (which have a claw on the first finger) 

 in scrambling about, and young Grebes at any 

 rate young Dabchicks can during the first week or 

 so of their lives only get about in this way on 

 land, or rather on the nest, which is all the land 

 they know. The really most interesting point 

 about the Hoatzin, then, would appear to be that 

 it is apparently a link between the nestling and the 

 chick types of young, having the imperfect clothing 

 so common in the former and the active habits of 

 the latter, though we are not told if it feeds itself 

 at all. 



So distinct is the separation between the two 

 types that there is only one case in which the 



