CALIFORNIA FISH AND GAME 



149 



been tortured by tliese quills working into their muscles, and when 

 they lodge in the mouth of an animal, death often results. 



Control operations as now conducted on the forests of the north- 



FiG. 45. A. Diagram for preparing a wooden cup for u.se in exposing poisoned 

 salt for porcupines ; B. Method of attaching poison block to pine tree. 



eastern section of .the State involve methods that have been worked out 

 during the past several years. Salt, of which the animals are very 

 fond, is treated with strychnine and exposed in small wooden blocks 

 five inches long cut from two- 

 by-four-inch lumber. Holes are 

 bored into each block and filled 

 with about three tablespoons of 

 the strychnine-treated salt to 

 which a small amount of dex- 

 trine has been added to make it 

 firm. 



These blocks are nailed to 

 trees frequented by porcupines, 

 and are securely held in place 

 by 30-penny nails above a limb 

 on which a porcupine may rest 

 while eating the salt (Fig. 45). 

 Such trees are clearly marked 

 with a yellow-tin poison sign 

 (Fig. 46). This tree-blocking 

 method is supplemented by den 

 poisoning, in which the poisoned 



STRYCHNINE 



POISONED BLOCK 



Porcupine Station 

 in this Tree 



CAUTION: -This Block must 

 be kept out of reach of 

 livestock at all times. 



U. S. DEPARTMENT OF AGRICULTURE 



Bureau of Biological Survy 



Fig. 46. Facsimile of tin poison sign 

 placed on each tree blocked. Black let- 

 ters on a yellow background. Actual 

 size 3J inches square. 



