REPORT OF THE SECRETARY OF AGRICULTURE. XLV 



DIVISION OF BIOLOGICAL SURVEY. 



FIELD WORK. 



Field work was carried on in California, Texas, New Mexico, 

 Alaska, Mexico, British Columbia, Manitoba, and the Northwest Ter- 

 ritories. The outlining of life zones in C^ifornia was continued in 

 the Coast Range and carried south to the Baj^ of San Francisco, under 

 the personal direction of the chief of the Division. During the 

 present season a careful examination will be made of that part of the 

 Sierra Nevada lying between Sierra Valley and the Yosemite, includ- 

 ing the region about Tahoe, Donner, Independence, and Webber 

 Lakes. 



In Texas special attention was given to the collection of data for 

 most accurately outlining the life zones in the southern half of the 

 State, and more particularly in the region along the Gulf coast from 

 Corpus Christi to Brownsville and west to the Rio Grande below 

 Laredo. A preliminary investigation of the most economical methods 

 of destroying prairie dogs was also undertaken. In view of the dam- 

 age caused by this pest not only in Texas, but also in several other 

 States in the arid region of the West, the destruction of these animals 

 is a practical question of great interest to many farmers and worthy 

 of thorough investigation by the Department. 



THE BELGIAN HAEE. 



Much interest in the Belgian hare has been developed during the 

 last three years, especially in California, Colorado, and other Western 

 States. But however valuable Belgian hares may be for meat or fur, 

 their introduction in large numbers is accompanied by a certain ele- 

 ment of danger which should not be overlooked. Some are sure to 

 escape, and the State Board of Horticulture of California has esti- 

 mated that several thousand of the animals are already at large in the 

 State. If they increase as rapidl}^ when at large as they do in captiv- 

 ity, they will undoubtedly become a source of danger, and stringent 

 measures may be required to keep them under control. Still more 

 dangerous would be the introduction of the Belgian hare into Porto 

 Rico, where the question of its acclimatization has already excited 

 interest. 



STUDY OF FOOD OF BIRDS AND BIRD PROTECTION. 



Laboratory and held studies of the food of birds, especiall}^ of 

 species of economic importance, have received much attention. The 

 object of these investigations is to obtain reliable information which 

 will enal)le the farmer to distinguish Vjetween species which are bene- 

 ficial and those which are injurious to his crops. Such knowledge 



