632 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1908. 



But all birds are not equally useful to man. Some are commonly 

 supposed to be positively harmful. Hence the economist does not 

 look upon all with equal favor. He divides the fowls of the air into 

 two classes— the friends and the foes of man. His policy is obviously 

 to encourage the former and to repress the latter. 



Unfortunately, it is by no means always easy to determine into 

 which category a particular species falls. A great many birds, as, 

 for example, flycatchers, feed exclusively on insects, and since these 

 latter may as a whole be regarded as man's most deadly enemies, it 

 follows that all purely insectivorous birds are his very good friends. 

 On this point there can be no difference of opinion. Nor can anyone 

 doubt that those fowls of the air which subsist mainly on insects are 

 of great utility to man. 



Mr. Maxwell-Lef roy writes in his Indian Insect Pests : 



A large number of birds are wholly insectivorous, a large number are partly 

 so, and every one of tliese deserves protection and encouragement. 



In other words, the great majority of birds are useful to man. 



FRIENDS OR FOES? 



But there exists a multitude of feathered creatures that are not 

 purely insectivorous. There are the raptores, which devour other 

 birds, small mammals and reptiles; the vultures which eat carrion; 

 and the birds which feed largely on fruit, grain, or fish. How are 

 these to be regarded ? This is a question which can be satisfactorily 

 answered only by considering each species separately, and ascertain- 

 ing the nature of its food at different stages of its existence, and under 

 various conditions, as, for example, in seasons of drought or excessive 

 rainfall, or at times when the country is invaded by some insect pest, 

 such as the locust. Even when we have succeeded in ascertaining this, 

 we are by no means always able to say whether the bird in question 

 is a friend or foe. Let us, for example, suppose that the species under 

 observation lives chiefly upon grain crops, but that it feeds its young 

 on harmful caterpillars. The caterpillar is a voracious creature, 

 which consumes several times its own weight of food in the course of 

 a day. Tlius, the devouring of a caterpillar is a work of merit, which 

 will outweigh the injury done by eating a considerable number of 

 food grains, but who is to say how many food grains go to a cater- 

 pillar? 



THE SPARR0W\ 



Take the common sparrow — a bird which has, of late, come in for 

 much abuse in the columns of The Times. It is of great importance 

 to determine the policy to be adopted toward him, for he has spread 

 himself over the greater part of the world. In India he is almost as 



