2 9 a ECONOMIC ZOOLOGY AND ENTOMOLOGY 



as to give much aid in determining the identity of birds in 

 nature. Note the flight of the woodpeckers; it identifies 

 them unmistakably in the air. Note the rapid beating of the 

 wings of quail and grouse; also of wild ducks; the slow, heavy, 

 flapping of the larger hawks and owls, and of the crows; and 

 the splendid soaring of the turkey-buzzard and of the gulls. 

 This soaring has been the subject of much observation and 

 study, but is still imperfectly understood. The soaring bird 

 evidently takes advantage of horizontal air-currents, and some 

 observers maintain that upward currents also must be present. 

 The speed of flight of some birds is enormous, the passenger- 

 pigeon having been estimated to attain a speed of one hundred 

 miles an hour. The long distances covered in a single continu- 

 ous flight by certain birds are also extraordinary, as is also the 

 total distance covered by some of the migrants. The differ- 

 ences in the structural character of the wings should be noted 

 in connection with the observation of the differences in flight 

 habit. The tongue and tail of birds are two other structures 

 the modifications and special uses of which may be readily 

 observed and studied. Note the structure and special use 

 of the tongue and tail of the woodpeckers; note the tongue 

 of the humming-bird; the tail of the grackles. 



Feeding Habits, Economics, and Protection of Birds. The 

 feeding habits of birds have been already repeatedly referred 

 to. The study of these habits is not only interesting but is, 

 of course, of much importance in that it is the character of 

 these habits that determines the economic relation of birds to 

 man, that is, whether a particular bird species is harmful or 

 beneficial. Casual observation shows that birds eat worms, 

 grains, seeds, fruits, insects. A single species often is both 

 fruit-eating and insect-eating. Do fruits or do insects compose 

 the chief food-supply of the species? To determine this more 

 than casual observation is necessary. The birds must be 

 watched when feeding at different seasons. The most effec- 

 tive determinations of the kind of food taken by various 

 birds has been based on examinations of the stomach of many 

 individuals taken at various times and localities. Much 

 work of this kind has been done, especially by investigators 



