260 FIELD ZOOLOGY. 



mole tunnels around among the grass roots in search 

 of his breakfast, he does not take the trouble to go back 

 and cover up the grass patch where he found a fat grub. 

 The juicy meal only fills him with a craving for more, and 

 on he goes. Field mice and skunks eat grasshoppers. 

 Fresh-water fishes are insectivorous to nearly fifty per 

 cent of their diet. Hence, and this is the valuable point, 

 these insectivorous animals cannot be destroyed by an 

 agency outside their own domain without disturbing the 

 nice balance of nature. Only in regions destitute of man's 

 presence is this balance most nearly preserved. Man 

 is the largest disturbing force. 



The study of birds should not be restricted to any 

 one season, nor to one locality; but should cover a year 

 at the very shortest for a locality and its surrounding 

 country. For instance, if you are in the country for your 

 special field, your study should cover also the nearby 

 town. The different zones of life ought to be investigated ; 

 the ground birds, the tree-top birds, the day and the 

 night fliers, the woodland birds and the birds of the open, 

 the morning and the evening birds, the shy birds and the 

 birds that like the society of their human neighbors. 



Their food habits should also be a matter of study. 

 Yo.u can be reasonably sure that when a bird is astir he 

 is doing one of three things : hunting for food, singing, or 

 looking after the home, either the prospective home, or 

 the home in possession. In addition, birds have individ- 

 ual traits; as pugilism, for the pure pleasure of downing 

 an opponent; poaching, running another bird off his 

 feeding-grounds because he is bigger and can do it; 

 blustering braggadocio, which, by the way, is often able 

 to gain its ends; and sly cunning, which quietly gets 

 ahead of the other fellow and leaves him wondering 



