250 FIRST LESSONS IN ZOOLOGY 



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 continuous flight by 

 certain birds are also cxtraordinar)-, as is also the total 

 distance covered b)' some of the migrants. The differ- 

 ences in the structural character of the wings should be 

 noted in connection with the observation of the differ- 

 ences in flight habit. 



The tongues and tails 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 (fig. 201) 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 are not only interesting, but 

 their determination decides the economic relation of birds 

 to man, that is, whether a particular bird species is harm- 

 ful or beneficial to man. 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 observa- 

 tion is necessar)'. The birds must be watched when 

 feeding at different seasons. The most effective way of 

 determining the kind of food which the bird takes is to 

 examine the stomach of many individuals taken at vari- 

 ous times and localities. Much \\-ork of this kind has 

 been done, especiall)- by investigators connected with 

 the Division of Biological Survey of the United States 

 Department of Agriculture, and ])amphlcts giving the 

 results of these in\'estigations can be had from the Divi- 

 sion. It has been distinctly shown that a great majorit)' 

 of Vjirtls are chiefl)' beneficial to man b}' eating noxious 

 insects and the seeds of \\ccds. Most birds common!}' 

 re])uted to be harmful, and fir that reason shot b\- farm- 



