CONTROL OF RODENTS AND PREDATORY ANIMALS 3 
INSTRUCTIONS PREVIOUSLY ISSUED 
Information regarding new developments and improved practices 
in control procedure has been made available to the field personnel 
and to cooperators of the bureau from time to time since the incep- 
tion of the cooperative work in 1915, in mimeographed and printed 
form, as well as by individual written instructions and personal con- 
tact. It is now desirable to compile the more important of the state- 
ments as to policy and specific directions in one publication. All 
control methods are based on fundamental research and give due 
consideration to safeguarding the useful and harmless forms of wild 
life and the public interests in general. Field methods have been 
adapted to meet varying local conditions as called for by research 
and the experience of field forces. Investigations and experiments 
are being continued, and as additional information becomes avail- 
able. field practices will be subject to such modifications and improve- 
ments as the conditions warrant. 
ANIMALS ON THE CONTROL PROGRAM 
THE INJURIOUS RODENTS 
Certain species of the rodents that in large numbers infest lands 
of value for crop or forage production must be eradicated locally to 
meet the requirements of agriculture and forestry. Those that figure 
most largely in the cooperative control operations in one part or 
another of their ranges are the prairie dogs, ground squirrels, pocket 
gophers, jack rabbits, porcupines, and native and introduced rats and 
mice. Other groups that locally become unduly numerous and de- 
structive may also on occasion come within the control program. It 
would be impossible to eradicate everywhere the ground squirrels, 
prairie dogs, and other rodents that range over vast areas of rela- 
tively worthless lands, and such action is not desirable, even on the 
public domain. In areas of economic importance, however, definite 
tracts are established where the rodents can be kept under thorough 
control, and operations are extended sufficiently to prevent rein- 
festation. 
THE PREDATORY ANIMALS 
The control of such predatory wild animals as coyotes, wolves, 
mountain lions, and bobcats is concentrated on areas where serious 
damage is being done to domestic stock, poultry, and game. Bears 
are not subject to control except when individually injurious to 
livestock or property. 
