158 



sparsely distributed. This is not true, however, of the birds 

 that frequent the salt marshes, where their food is widely and 

 evenly spread like seeds in a grassfield. Hence Plovers, Sand- 

 pipers and their allied species forage in flocks, like the graniv- 

 erous birds, though they feed exclusively upon an animal 

 diet. 



I haye said nothing of the foraging habits of the Swallow 

 tribe, for these are very well known and understood. The 

 swallows are the guardians of the atmosphere, which would 

 otherwise swarm with fatal quantities of minute insects ; the 

 Woodpeckers are the guardians of the timber of the forest, and 

 the Sylvians and Flycatchers of the foliage. Blackbirds, Plo- 

 vers, Larks and Thrushes are the natural guardians of the soil 

 and. of the creeping herbage. Each tribe has its respective du- 

 ty to perform in the economy of nature ; and man must beware 

 how he disturbs her equilibrium, by reducing the numbers of 

 any species below the amount of supplies which the insect world 

 affords them. 



It is curious to notice the assiduity with which insects are 

 hunted in all the various stages of their exi&tence. In their 

 larva state, those that lurk under the soil are hunted by Black- 

 birds, by Thrushes and by the Common Kobins, who easily de- 

 tect their hiding places by the appearance of vegetation. Those 

 infesting the wood and bark of trees are hunted by Woodpeck- 

 ers who are no less sagacious in discovering the retreat of their 

 prey and dislodging it. When the larva has assumed the form 

 of Moths, Beetles and other perfect insects, these are attacked 

 by Blue-Birds, Wrens, Flycatchers and hosts of other birds, 

 who watch for them in all situations, in the daytime : and in 

 the night by Whippoorwills, Nighthawks and the little owls. 

 It matters not in what stage of its existence the insect is des- 

 troyed ; but it is demonstrable that the insect tribes cannot be 

 kept in check, unless they are attacked in all the stages of their 

 being ; and birds are their only effectual destroyers. Man 

 cannot by direct means cause their destruction, except in par- 

 ticular locations. He cannot be a general destroyer ; and their 



