294 PROTECTION AGAINST ANIMALS 



on any part of the stem or on the branches as the animals 

 climb the trees. When gnawed completely around that por- 

 tion of the tree above the injury dies. 



KilUng the porcupines is the best remedy. A bounty placed 

 on the animals will stimulate reduction in their munbers. 



Rabbits. — Gnawing of the bark in winter, often causing 

 the girdling and death of the tree, is done by rabbits. Seed- 

 lings and small trees are chiefly affected. Hardwoods are 

 preferred rather than coniferous species. Rabbits are some- 

 times so numerous and so destructive as to prevent repro- 

 duction. In such a case virtual extermination may be neces- 

 sary to control the pests. 



Squirrels. — Squirrels eat seeds and fruits and bite off 

 young shoots and buds. In many instances they devour 

 practically all of the seed crop of given species. Conse- 

 quently squirrels are often an important factor in the securing 

 of natural reproduction. 



Shooting of squirrels should be encouraged as the most 

 practicable method of protection. 



Mice. — Seeds are devoured by mice, which are particu- 

 larly to be feared in nursery seedbeds. Mice, during the 

 winter when food is scarce, gnaw the bark of seedlings and 

 young trees either above or below ground, often girdling them 

 and causing death. The mice are most abundant on grass 

 covered areas with sunny aspect. Periodically the mice are 

 likely to increase and girdle a large proportion of the trees on 

 restricted areas. In nurseries intensive methods of combat- 

 ing mice are warranted and can be successfully applied. In 

 the forest poisoning may be justified when the mice are 

 abundant, and the injury concentrated. 



Birds. — The beneficial influence of birds in destro)dng 

 insect enemies outweighs their mjurious effects upon the 

 forest. Birds feed upon the seeds of forest trees, bite off the 



