THEIR RELATION TO ANIMALS 137 



gaged in feeding on fruit or grain ; but I would absolute- 

 ly prohibit their killing at any time as a mere matter of 

 sport. I would be in favor of protecting every bird not 

 absolutely harmful ; but of no protection whatever to any 

 animal merely for the purpose of keeping it to be shot 

 at during some specified period by so-called sportsmen. 



I have no point of difference with those who are 

 seeking the protection of bird and other animal life. 

 I simply wish to record my disagreement with some of 

 the reasons and arguments advanced by them, and to 

 guard against an exaggerated belief in the value and 

 usefulness of our furred and feathered friends. 



Interference with natural conditions by introducing 

 new factors does not always turn out well and should 

 not be resorted to without a careful preliminary study 

 of possible consequences from all points of view. When 

 the English sparrow was introduced into North America 

 only one point was kept in mind: get something that 

 will eat the span-worm, the larva of the geometrid 

 moth, Ennomos subsignaria. The sparrow really did 

 accomplish that feat; but is now a greater nuisance 

 than the span-worms ever were and is a direct pro- 

 tector of certain species which never occur in trouble- 

 some numbers outside the region dominated by it. 

 The common Tussock or vaporer moth of the east is an 

 excellent example of this, and hardly less striking is the 

 case of the wood-leopard moth which has not become 

 injurious in this country anywhere except in cities and 

 towns where the sparrows keep all other birds out. 



Chickens, ducks, geese, and especially turkeys and 

 guinea-fowl are great feeders on insect life and may 

 sometimes be used practically, and the useful hog 

 esteems wire- worms, white grubs and similar creatures 

 as tid-bits to be eagerly sought and worthy of con- 

 siderable rooting for. 



