332 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



of mapping the life zones of North America. Technical laboratory 

 studies also are made of both birds and mammals, these activities 

 providing the basic scientific information needed in connection with 

 the rapidly growing economic work of the bureau. Scientific in- 

 formation is supplied on request to other governmental departments, 

 State organizations, and individuals. 



4. Alaska reindeer and fur bearers, E. W. Nelson and W. F. Ban- 

 croft in charge. Investigations are made of the diseases and para- 

 sites of reindeer, together with grazing and herd management and 

 breeding experiments on the mainland and in the Aleutian Islands; 

 also through a warden service laws are enforced for the protection 

 of the land fur-bearing animals of Alaska; and islands are leased for 

 fur farming, and investigations made for the upbuilding of the 

 fur- farming industry in the Territory. 



5. Game and bird reservations, H. F. Stone in charge. This 

 division covers work connected with the maintenance and super- 

 vision of a warden service on the larger reservations, building and 

 upkeep of game-proof fences and wardens' quarters, posting of 

 boundaries, and hay farming and feeding of elk on a large scale 

 at the winter elk refuge. „ 



6. Migratory-bird treaty and Lacey Acts, G. A. Lawyer in charge. 

 Activities under this division cover the maintenance and super- 

 vision of a warden service throughout the United States and in 

 Alaska for the enforcement of the migratory-bird treaty and Lacey 

 Acts, the former protecting birds migrating between the United 

 States and Canada and the latter dealing with unlawful interstate 

 commerce in game and the supervision of importations of living 

 foreign birds and mammals to prevent the introduction of harmful 

 species. 



ECONOMIC INVESTIGATIONS. 



The establishment during October, 1921, of a well-equipped labora- 

 tory at Denver, Colo., for investigating poisons and their prepara- 

 tion and use will be an important factor in increasing the effective- 

 ness of campaigns for the destruction of predatory animals and 

 harmful rodents. Necessary machinery has been installed in the 

 laboratory to process or otherwise prepare all the poison needed 

 by field parties of the bureau and cooperators throughout the 

 country. During the year the processed strychnine prepared 

 amounted to more than 10,000 ounces. Investigations in the use 

 of poisons have already resulted in greatly increased effectiveness 

 and lowered cost of operations. 



Appreciation of the practical value of the methods developed by the 

 Biological Survey for the destruction of predatory animals and in- 

 jurious rodents is shown indisputably by the continuance of substan- 

 tial financial support from cooperating States, organizations, and 

 individuals, amounting to $096,379 for the year. More than 105,000 

 men took part in the work, and from their reports it is estimated 

 that a saving was made of crops and live stock amounting to more 

 than $10,000,000. 



The continuous campaigns against injurious animals are grad- 

 ually eliminating large gray wolves over most of their former 

 range and will gradually wear down the numbers of all predatory 



