328 The Crane-like Birds 



The family is divided into three subfamilies, the Grumce, or true Cranes, the 

 Aramince, or Courlans, and the Psophiincs, or Trumpeters. The especially distin- 

 guishing marks will be set forth under each heading. 



The Cranes (Subfamily Gruince). Although externally resembling the 

 Herons and Storks with which, indeed, they were formerly united, the Cranes 

 really constitute a very well marked group of birds, no one of which is 

 likely to be confused with any other when once their distinctive characters 

 are understood. They are all birds of large size and frequent grassy plains 

 as well as marshes. They have long legs and neck, generally a long bill, 

 which is equal to or longer than the head, and long wings in which the 

 inner secondaries are rather longer than the primaries, and are generally 

 composed of drooping plumes with more or less dissociated webs. The tail 

 is rather short and composed of twelve feathers. The toes are short, espe- 

 cially the posterior toe, which is so much elevated above the other three that 

 its claw scarcely touches the ground. The powder-down patches, so char- 

 acteristic of the Herons, are absent, except in the anomalous Kagu and the 

 Sun-Bitterns. In the structure of the skeleton and the soft parts the Cranes 

 depart widely from the Herons and Storks, the most important difference being 

 the split (schizognathous) instead of the band form of the palate, and the slit- 

 like (schizorhinal) form of the nostrils. A further structural feature of much 

 interest, which is present in most Cranes, is afforded by the great length and 

 peculiar convolution of the trachea or windpipe. In the young chick, as it is 

 about to emerge from the egg, the windpipe is said to be perfectly simple, but 

 with advancing age this organ elongates and coils upon itself, after the manner 

 of a French horn, within the keel of the breast-bone. The extent of this coiling 

 appears to reach its maximum development in the Whooping Crane, when 

 a length of no less than twenty-eight inches of the windpipe is packed away 

 within the hollowed keel before it passes into the lungs. The entire length of 

 the windpipe in this bird is about five feet, which is nearly or quite the total 

 length of the bird itself. It is apparently upon this great length of the trachea 

 that the powerful, resonant, and trumpet-like voice of the Cranes depends, as 

 on a similar organ does the voice of the Trumpeter Swan. It has been said 

 on high authority that a striking point of difference between the Whooping 

 and Sandhill Cranes is the absence of convolutions in the trachea of the latter, 

 but this is incorrect, for while not convoluted to as great an extent in the former 

 it is nevertheless distinctly folded. Beautiful preparations of the trachea of 

 all three American species are in the United States National Museum, and all 

 are distinctly convoluted. 



Another distinguishing mark is afforded by the condition of the nestlings, 

 these being covered with down and able to run about within a few hours after 

 they are hatched. The feather-tracts and their disposition are also quite peculiar. 



The Cranes number about nineteen species and are distributed over the 

 whole of North America as far south as Mexico and Cuba, and the greater part 

 of Europe and northern Asia, whence they extend into northeast Africa, Lower 

 Egypt, northwest India, and the Yangtse basin in China. In the more north- 



