158 FORAGING HABITS OF BIRDS. 



buntings exceedingly attractive. Their food is not dis- 

 tributed in separate morsels like that of robins and wood- 

 peckers. It consists of the seeds of grasses and of com- 

 posite plants, which are often scattered very evenly over 

 a wide surface. When, therefore, a Hock of fifty or more 

 settle down in a field, each one fares as well as if he 

 were alone, during the short time they remain on the 

 spot. Insect-feeders find it for the most part profita- 

 ble to scatter and keep separate, because their food is 

 sparsely distributed. This is not true of the birds that 

 frequent the salt-marshes that are overflowed by the 

 tide. Their aliment consists of insects and worms which 

 are evenly scattered and abundant. Hence sandpipers 

 and some other species forage in flocks, though they live 

 exclusively upon an animal diet. 



The swaUow tribes are the guardians of the atmosphere, 

 that would otherwise swarm with fatal quantities of mi- 

 nute insects. Their foraging habits are observed by all, 

 and are well known. Woodpeckers, creepers, and chicka- 

 dees are the guardians of the timber of the forest ; sylvians 

 and flycatchers, of the foliage. Blackbirds, thrushes, crows, 

 and larks are the protectors of the surface of the soil ; 

 snipes and woodcocks, of the soil under the surface. Each 

 family has its respective duties to perform in the economy 

 of nature; and man must beware lest he disturb this 

 equilibrium by reducing the numbers of any species below 

 the supply of insects which is afforded them. 



It is curious to note the assiduity with which insects 

 are hunted in all stages of their existence. In their larva 

 state, those that lurk inside of the wood and bark are 

 taken by woodpeckers, and those under the soil by 

 snipes and woodcocks. Insects, when the larva has as- 

 sumed the form of moths, beetles, and flies, are attacked 

 by flycatchers and sylvians and other small birds that 

 take their food by day, and by small owls and whippoor- 



