Instances of Unsound Practice 
(A)  "Range land worth $2 per acre is poisoned at a cost of 10, etc."

This has been discussed above under cost of operations. So often this 
range land is the breeding ground and source of reinfestation of highly valu-

able lands. Under such circumstances it may be economically sound to pay
25/ 
per acre to poison the range land. The cost per acre, however, should be

charged also against the acres of valuable land that have been protected.

One who has carefully observed the feeding and living habits of rodents,

particularly the California Ground Squirrels, and how general their distribu-

tion in all types of country is, sees nothing strange about the difficulty
of 
making relief permanent even after one to three poisonings. An illustration

of this occurred in the California National Forest in 1914 to 1918. The glades

and meadows of this Forest in 1914 were heavily infested with the Douglas

ground squirrels.  The carrying capacity reduced 30%.  The first and second

year just these open areas were poisoned and the squirrel populations in
them 
at the time reduced 95% to 98% but in the spring of 1916 there were many

squirrels again present in these meadows, much to our chagrin. Careful in-

spection revealed that these squirrels were well distributed thru the open

timber areas and in the brushy patches. In 1916 and 1917 several crews were

employed to poison a solid block of the forest, comprising about 350,000

acres. After this poisoning the few remaining squirrels gathered in the 
glades and meadows and roving crews in 1918 so reduced the populations that

Forest Rangers have since been able to keep the squirrels under control by

carrying a little poisoned grain with them on their other lines of duty and

poisoning where they see colonies starting again. This benefitted not only

the range treated but stopped the migration to the agricultural lands below

the forest. It cost from 5X to 25/ an acre to reduce this population of 
 
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