DAMAGE CAUSED BY ANIMALS. 81 



CHAPTER II. 



DAMAGE CAUSED BY ANIMALS. 



42. The Animal World in relation to Forest Growth ; Classifica- 

 tion of Animals injurious to Forests. 



Numerous as are the various kinds of animals dwelling in our 

 woodlands, just as manifold are the relations in which they stand 

 to timber crops in respect to their nourishment, their reproduc- 

 tion, and their whole habit of life. Not a small portion of these 

 animals is directly nourished by the products of forests and of 

 woodland soils ; another also lives indirectly therefrom through 

 the nourishment obtained from animals of the woods, either 

 exclusively or in combination with vegetable products ; whilst a 

 good many birds and insects do more or less damage to trees, not 

 only externally, but also internally, by forming their breeding- 

 places there. 



The question, as to which of these animals may be regarded 



as useful, and which injurious, from a sylvicultural point of view, 



can be answered absolutely in the affirmative or negative only as 



j regards a portion of them. Thus, for example, the parasitic insects 



and the predatory species, as well as insectivorous birds, are 



! unquestionably useful, whilst, on the other hand, animals of the 



j chase (except those of predatory habits), mice and voles, and so- 



I called true forest insects, must undoubtedly be considered injurious 



! to woodlands. With regard to a great many other animals, only 



a modified answer can be given, as, for instance, in the case of 



I birds (Finches, Jays) which eat seeds and grain as well as insects, 



and of predatory animals (Owl, Buzzard, Marten, Weasel) that, 



! besides preying on injurious animals (Rabbits, Mice and Voles, 



j Insects), also devour useful birds and disturb their breeding. 



The grazing of domestic animals in the woods is also, as a rule, 



disadvantageous, although there may be cases in which the graz- 



,ing of cattle may be of advantage in keeping back the growth of 



F 



