148 CALIFORNIA FISH AND GAME 



PORCUPINE CONTROL ON FORESTS 

 OF CALIFORNIA 



By Joseph Keyes, Leader, Rotlent Control, 

 Bureau of Uiological Survey 



For years many sportsmen, hunters and lovers of outdoor stories 

 believed that the porcupine was protected by law. Even today, when 

 statements are made that the Federal Government is actually enyayed 

 in the control of porcupines, many comments are heard that would 

 indicate that there are still some who believe these animals to be 

 protected. The fact is, however, that these rodents are not protected 

 in the United States, and, moreover, that two Eastern States have been 

 paying bounties on them for several years. 



Losses occasioned by the attacks of porcupines on our national 

 forests have been recognized for several years, and it has been reported 

 in the Southwest that the damage caused by these animals exceeds 

 that resulting from fires. The peculiar type of attack wherein the 

 tree may be completely girdled, especially near the top, may be seen 

 on many areas of the Modoc, Lassen, and Plumas National Forests in 

 California — especially along the eastern slopes. Damage is also 

 apparent on the Tahoe, Eldorado, and ^Nlono Forests. 



Porcupines consume succulent plants of many species, and the 

 buds, leaves, inner bark, and cambium of numerous kinds of trees. In 

 general, during summer they feed on juicy ground vegetation. Their 

 fall and winter diet consists largely of bark and leaves of coniferous 

 trees, especially the western yellow pine and several species of juniper. 



During the late summer, fall, and Avinter months, porcupines, in 

 1h('ii' ctforts to get at the inner layer of bark, often partly or completely 

 girdle the main leaders, or boles, of the trees. Many of the small 

 seedlings are com])lelely consumed, while larger ones frequently suffer 

 injuries serious enough to cause their death, but more often this injury 

 results in a weakened bushy-topped or spike-top tree that is useless for 

 commercial purposes. Deep snow may hold these animals to individual 

 trees for periods of one to three months, in which time the tree may 

 be completely ruined. 



Fortunately, the rate of reproduction of porcupines is not rapid. 

 They breed but once a year and produce one young (rarely two), born 

 fully quilled. I\Iany attain the weight of 80 jiounds and live to a ripe 

 old age. The quills are white, with dark ti})s, sharp, and finely barbed 

 at the tip, and are used as a means of defense, the greatest damage 

 being inflicted by the porcupine striking an object with its powerful 

 tail. The quills are not thrown. Many domestic and wild animals have 



* This paper is published to acriiiaint (ho roaders of Cat.tfoiinia Fish and Game 

 with tlie reasons for and mctliods of Federal porcupine control work in California. The 

 Pivision lias, as yet, taken no definite stand regarding this work, but is watching' 

 its results closely, especially as regards the incidental poisoning of harmless or 

 beneficial species of animal life. No evidence of the destruction of such species 

 incident to this campaign has been procured to date. — Ed. 



