BUEEA-U OF BIOLOGICAL SURVEY. 253 



GROUND SQUIRRELS. 



The work of exterminating ground squirrels on Government lands 

 within the Fort Totten Indian Keservation^ North Dakota, and the 

 Sequoia and California National Forests of California, has been 

 continued, and 208,553 acres have been practically cleared of these 

 destructive pests. The result has been increased productiveness of 

 the lands treated, and also the protection of the crops on adjacent 

 areas. The total cost of this work, including labor, has been ap- 

 proximately 5 cents per acre in North Dakota, and 6 to 7 cents in 

 California. 



The methods employed by the bureau have been demonstrated 

 among farmers, who have cooperated in poisoning ground squirrels 

 on holdings adjacent to the public lands treated. In North Dakota 

 organized campaigns against ground squirrels in cooperation with the 

 State Extension Service have continued with increased vigor and 

 thoroughness. The squirrels on about 7,500,000 acres were poisoned 

 during the year by 19,000 cooperating farmers. This resulted in the 

 practical extermination of the pest on the areas treated and a saving 

 in this year's crops valued at more than $1,000,000. Similar savings 

 ma}'^ readily be effected elsewhere in the vast areas infested by these 

 animals. 



Campaigns along the same lines, under project agreements, have 

 been started in Montana, Idaho, and Oregon in cooperation with 

 State extension services and are being planned for other States. 

 Demonstrations of methods have been made on a large scale in 

 Nevada and California, where increasing interest is being developed 

 in organizing systematic campaigns for the extermination of ground 

 squirrels. 



RABBITS. 



Serious depredations by jack rabbits upon wheat, barley, oats, 

 alfalfa, and other growing crops and stacked hay necessitated con- 

 tinued efforts for their control in eastern Oregon, California, Idaho, 

 Nevada, Utah, Colorado, New Mexico, and Texas. Effective methods 

 of poisoning the animals were demonstrated and successful cam- 

 paigns in farming communities organized against them. This work 

 was very successful and enormous numbers of animals were killed. 

 In a single county in Oregon about 75,000 were poisoned at a cost of 

 less than one-tenth of a cent each. 



Cottontail rabbits have damaged orchards, grain, and truck farms, 

 especially in Virginia, West Virginia, Maryland, Delaware, and New 

 Jersey, and advice and demonstrations have been given for protection 

 against them. 



The European hare, introduced into New York some years ago, has 

 increased and is spreading rapidly in southern New York and adja- 

 cent States, where it has done extensive damage to orchards. Investi- 

 gations have been started to discover methods for the control of this 

 animal, which threatens to become a dangerous pest. 



PRAIRIE-DOGS. 



Campaigns against prairie-dogs upon national forests and other 

 public lands have been prosecuted vigorously in Arizona, Niew 

 Mexico, Wyoming, Colorado, and Montana. The first poisoning of 



