r38 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1925 



serve the same scantiness of vegetation, the monotonous growth 

 that gives no color to the landscape, the absence of trees, the thorni- 

 ness of the plants, the short active season in which flowers rapidly 

 bloom and as rapidly die away. These are some of the desert 

 features which we meet with in our journey through Tibet. 



Let us consider the life of this high-altitude desert. How do th'j 

 creatures live? How do thoy protect themselves? By what moans 

 are they adapted to the conditions of the heights? 



Anyone who has traveled in a low-lying desert knows how impor- 

 tant is protective coloration in the general scheme of things. It is 

 exactly the same in Tibet. Examples are apparent on every side. 

 Most of the common animals of the plateau are inconspicuous against 

 the soil. But Ave must remember that the plateau is littered with 

 stones, and not like many low-lying deserts, an even layer of sand. 

 This gives an additional advantage to the animals. For not only do 

 tlioir colors blend with the surface, but their shapes and outlines are 

 often lost to view, being confused Avith the scattered stones. 



I Avill give some examples of protective color in Tibet. Every- 

 Avhere on the plateau we meet Avith colonies of pikas, delightful 

 little creatures Avhich sit near their burroAvs and blend Avith the 

 sand}'^ soil. In the gorges of the main range we find another species. 

 Its surroundings are more gloomy; it lives amongst rocks, and in ac- 

 cordance Avith this its coat is darker so as to fit it to these special 

 haunts. The marmots likewise blend Avell with the altitudes. They 

 like to occupy the bare passes as high as 17,000 feet. The Tibetan 

 hare is a good example of harmonization, especially Avhen it sits 

 amongst fallen stones. Some of the larger animals are protectively 

 colored. The Tibetan gazelle is the color of the plateau, and a herd 

 of burhel is inconspicuous against a hill. 



The majority of the birds are protectively colored. The different 

 kinds of mountain finches, the Tibetan skylark, the short-tood lark, 

 the calandra lark, the ^Mongolian sandplover, are all colored so as to 

 harmonize Avith the soil. They all live on the open plateau where 

 there is nothing to conceal them from vicAv. Two of the birds liaA'o 

 conspicuous markings, but these do not interfere Avith the concealing 

 effect. The desert chat, for example, has white patches on its wings 

 Avhich disappear from view Avhen the bird alights. The horned lark 

 has black markings on its neck and breast, but these are sufliciently 

 well concealed from a hawk or other enemy soaring overhead. The 

 Tibetan sand grouse is an excellent example of harmonization; .so 

 IS the magnificent Tibetan snow cock Avhen feeding amongst the 

 boAvlders and crags. The cliffs and torrents also provide examples. 

 The wall creeper lives around the fort at Shekar, and as it climbs 

 about the slaty rocks the color of its back blends Avith the stone. The 



