210 USEFUL BIRDS. 



tracted by the berries of the mountain ash. The northward 

 migration is usually under way in March, but comparatively 

 few birds are ordinarily seen in central Massachusetts until 

 late in May. In spring and early summer they seem to feed 

 almost entirely on insects. They are always plentiful at this 

 season in a cankerworm year, and they deserve at such 

 times the local name of "cankerworm birds," for they fre- 

 quent infested orchards in large- flocks, and fill themselves 

 with the worms until they can eat no more. There is no 

 doubt that the countless thousands of caterpillars that they 

 destroy more than compensate for the cherries they eat, 

 although in some seasons they are very destructive to cherries. 

 Such little gluttons rarely can be found among birds. The 

 Cedar Bird seems to have the most rapid digestion of any 

 bird with which experiments have been made. Audubon 

 said that Cedar Birds would gorge themselves with fruit 

 until they could be taken by hand ; and that he had seen 

 wounded birds, confined in a cage, eat of apples until suffo- 

 cated. They will stuff themselves to the very throat. So, 

 wherever they feed, their appetites produce a visible effect. 

 Professor Forbes estimates that thirty Cedar Birds will 

 destroy ninety thousand cankerworms in a month. This 

 calculation seems to be far within bounds. 



Cedar Birds are devoted to each other and to their young. 

 Sometimes a row of six or eight may be seen, sitting close 



together on a limb, passing 

 and repassing from beak to 

 beak a fat caterpillar or juicy 

 cherry. I have seen this 

 touching courtesy but once, 

 and believe it was done not 

 so much from politeness as 



Fig. 75. -Passing the cherry. „ , 



from the fact that most of 



the birds were so full that they had no room for more, a 



condition in which they can afford to be generous. Never- 

 theless, the manner in which it is done, and the simulation 

 of tender regard and consideration for each other exhibited, 

 render it a sight well worth seeing. They also have a habit 

 of " billing," or saluting one another with the bill. 



