240 ANNUAL EEPOETS OF DEPARTMENT OF AGEICTJLTURE. 



DISTRIBUTION MAPS OF PRAIRIE DOGS. 



During the first part of the year work was continued platting in 

 detail the distribution of prairie dogs over a large area in eastern 

 Arizona. This demonstrated that prairie dogs are rapidly extending 

 their range and travel surprisingly long distances to locate new colo- 

 nies, a few individuals being found sometimes from 6 to 8 miles from 

 the nearest inhabited prairie-dog area. This shows the necessity for 

 destroying scattered colonies of these pests in order to prevent rapid 

 occupation of great areas of new country. 



BIOLOGICAL SURVEYS. 



Progress was made on the biological surveys of Oregon and North 

 Dakota, in cooperation with local institutions. The survey of Ala- 

 bama was nearly completed and a considerable advance made on that 

 of Arizona. A final report with map on the biological survey of 

 Wyoming was prepared for publication, and reports on the birds and 

 mammals of New Mexico, based on the survey of that State, were 

 nearly completed. 



INVESTIGATIONS OF LARGE GAME ANIMALS. 



Special attention is being paid to securing information and speci- 

 mens for study concerning the large game animals of North America. 

 The need of this is emphasized by the rapid decrease of certain 

 species and their extermination throughout large areas where once 

 they were plentiful. The bureau has had the active cooperation of a 

 number of men who have visited remote districts in the United 

 States, Canada, and Alaska for the purpose of securing information 

 and specimens of large game, which they have freely contributed to 

 the bureau. These expeditions have been made at the personal ex- 

 pense of the collaborators and the results secured have been of great 

 value. 



INVESTIGATIONS RELATING TO MIGRATORY WILD FOWL. 



In connection with the administration of the migratory-bird law 

 an investigation is being made of the food plants of wild fowl in 

 their haunts, and at the same time of the present status of migratory 

 species in various parts of the United States. The results, published 

 together, will form an invaluable stock of information for use in 

 connection with measures taken to increase the food supply of our 

 wild fowl and otherwise to conserve this valuable national asset. 



TECHNICAL INVESTIGATIONS. 



A large number of birds and mammals were identified on request 

 of State and other institutions and individuals throughout the coun- 

 try. A monograph of the marmots was published and technical 

 studies of North American moles and pocket gophers were com- 

 pleted. Much work also was done on other groups of mammals, 

 concerning the number of species of which and their relationships 

 little was known. 



