10 THE POOD OF BIRDS IN INDIA. 



any species of bird fed almost entirely on one species of weed and 

 there seemed to be every possibility of that weed being eliminated, 

 the bird, finding its food supply diminishing, would migrate. It is 

 a proved fact that the presence of at any rate a fair number of 

 species of birds in certain districts is to a large extent regulated by 

 food supply. And again, many birds eating weed seed will take a 

 considerable amount of grain from standing crops and seeds from 

 seed crops in many instances. 



OMNIVOROUS BIRDS. 



Omnivorous birds are both insect and vegetable feeders, and 

 their diet also contains various other forms of food. This group as 

 here arranged contains all birds which cannot be classed with insec- 

 tivorous or vegetable feeding birds. It could well be subdivided 

 into two or three specialised groups, as shown on page 26. 



Animal Diet other than Insects. This class of food, together with 

 insects and grain, comprises the food of omnivorous birds. This 

 forms a large proportion of the food of many birds, often comprising 

 the total food of some species. In many instances, however, birds 

 taking such food will also have a portion of their diet composed of 

 insects or vegetable material. Such diet comprises the following : 



Mammals which the bird either eats as carrion, or else kills 

 itself, birds, frogs, reptiles, fish, mollusca, Crustacea, spiders, excreta 

 and offal. 



Mammals. Hawks and owls are practically the only classes 

 which take mammals for food, though there are others that do so 

 occasionally, such as shrikes, rollers, &c., and these cannot be 

 regarded in most cases as injurious if so doing : a few kids and lambs 

 may be taken, and if so the individual bird that does so can be 

 destroyed. In so me few cases too, small beneficial mammals such as 

 shrews are taken. Otherwise these classes of birds are beneficial 

 and need protection only from skin and egg collectors. They will 

 not, as a rule, be destroyed for plumage, and certainly not for food. 

 Many hawks and owls feed extensively on large insects also, prin- 

 cipally Orthoptera, and Lepidopterous larvse. 



