CHAPTER XrX 



PROTECTION AGAINST ANIMALS — OTHER THAN 

 INSECTS AND DOMESTIC ANIMALS 



The principal animals, not previously considered, causing 

 damage to tree crops include deer, beaver, porcupines, rab- 

 bits, mice, squirrels and birds. Injuries resulting from the 

 work of these animals are less extensive in the aggregate than 

 those produced by any of the four injurious agencies described 

 in the preceding chapters. However, in individual cases, rela- 

 tively large losses may ensue from the attacks of any one of 

 these animals. 



Deer. — Deer cause injuries of the same type as those 

 produced by domestic animals. The numbers of deer are 

 ordinarily too small to efifect serious damage except on occa- 

 sional, scattered trees. Other than by restricting the num- 

 ber of deer in a forest through shooting them, injury by deer 

 cannot under present economic conditions be prevented. 



Beaver. — Beaver by girdling and felling trees, often of 

 merchantable size, kiU a good many trees in the vicinity of 

 their ponds and dams. Certain species, particularly the 

 aspens, are preferred and the beaver will go a considerable 

 distance to find the favored species if not available close at 

 hand. They may destroy the entire stand adjacent to their 

 ponds by raising the water level thus submerging the root 

 systems of standing trees or at least increasing the moisture 

 content of the soil. Beaver are relatively scarce and in only 

 a few regions are they a nuisance. 



Porcupines. — Damage by porcupines consists in the 

 gnawing of bark on standing trees. The injury may occur 



293 



