95 



PKOTECTION AGAINST ANIMALS. 



INTRODUCTORY EEMAEKS. 



THE question of the usefulness or hurtfulness of wild animals 

 indigenous in Europe may be considered from a forest, sporting, 

 or agricultural point of view. Under Forest Protection only 

 the forest point of view will be considered, but even under this 

 heading some difficulty will be experienced, for the following 

 reasons* : 



1. A number of animals are at the same time both useful 

 and injurious to forests. 



2. The degree of utility or harm done by one and the same 

 animal differs according to its age, to local circumstances 

 (season of the year, condition of the woods, etc.), so that it 

 is hardly possible to lay down definitely that certain animals 

 are absolutely injurious, or useful. Thus, the fox, though a 

 great enemy to barn-door fowls and game, may be very useful, 

 especially in a broadleaved forest, which suffers more than 

 coniferous woods from rodents. Thrushes and blackbirds in 

 spring and summer feed mainly on worms and insects, but in 

 autumn chiefly on berries. The cuckoo and bats are always 

 useful, while bark-beetles, the Nun-moth and other insects are 

 absolutely injurious to forests. 



3. The utility of certain animals to forests may be direct, 

 or indirect. Thus the jay may be directly useful by carrying 



* Intentional introduction of exotic animals to combat insect pests have not 

 always proved advantageous. Thus, European sparrows were introduced into 

 the N.-E. States of America in 1850 and 1867 to destroy canker-worms. The 

 sparrows are now an unmitigated pest throughout N. America, while the canker 

 worm has been replaced by a worse insect, which the sparrows never touch. 

 Similarly the mongoose was introduced into Jamaica in 1872 to destroy the cane- 

 piece rat. This it did in ten years, but since then it has proved most destructive 

 to ground-nesting birds, to insectivorous reptiles and batrachia, as well as to fruits 

 and vegetables, so that the mongoose does much more damage than the rat. On 

 the other hand the Australian ladybird (Vedalia cardinalls) introduced into 

 California in 1889, has saved the citrus-growing industry from the cottony 

 cushion scale, Icarya purchasi. 



