78 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



birds, which, in some uncanny manner, are able to locate infested 

 territory far removed from their usual place of residence." 

 Forbush (1927) says: 



In seasons when caterpillars of any species are abundant, cuckoos usually 

 become common in the infested localities. They follow the caterpillars, and 

 where such food is plentiful, the size of their broods seems to increase. During 

 an invasion of forest tent caterpillars in Stoneham, Massachusetts, in May, 

 1898, Mr. Frank H. Mosher watched one of these birds that caught and ate 30 

 of these insects inside of five minutes. He saw another in Maiden eat 29, 

 rest a few minutes and then eat 14 more. In July, 1899, he reported a family 

 of these birds in a locality infested with the gipsy moth, and said that they 

 were eating large quantities of gipsy caterpillars. In June, 1895, Mr. Henry 

 Shaw reported great numbers of these cuckoos in Dorchester feeding on the 

 same pests. The late Professor Walter B. Barrows, of Michigan, an extremely 

 conservative ornithologist, is responsible for the statement that in several in- 

 stances remains of over 100 tent caterpillars have been taken from a single 

 cuckoo's stomach. The Black-billed Cuckoo, because more common than the 

 Yellow-billed, is the species that most commonly attacks this insect in New 

 England orchards. During an invasion of army worms. Professor S. A. Forbes 

 found that 95 per cent of the food of this species consisted of that caterpillar. 



F. H. King (1883), writing of the food of the black-billed cuckoo 

 in Wisconsin, says : "Of thirteen specimens examined, nine had eaten 

 caterpillars — among them were eight of the fall web-worms {Hy- 

 phantria textor), thirtj^-three of the oak caterpillars {Dryocampa 

 senatoria)^ one of the lo caterpillars {Satumia io), six of the antiopa 

 caterpillars (Vanessa antiopa), and one of the caterpillars of the 

 archippus butterfly {Dartxiis archippus). One contained five larvae 

 of the large saw-fly {Cyrabex a^nericana) ; six, twenty-five grass- 

 hoppers ; one, a cricket ; two, ten beetles ; and two, two harvest-men." 



Other authors have charged this cuckoo with eating minute rhol- 

 lusks and other small animals, fishes and aquatic larvae, fruits and 

 berries, and even the eggs and young of small birds. On the latter 

 point, Henry D. Minot (1877) says that "they do great mischief in 

 destroying the eggs of other useful birds. Like arrant cowards, as 

 they are, they take opportunities to approach stealthily the nests of 

 many birds, whom they would be afraid to encounter, and then feast 

 on the eggs of the absent parents, after which they hurry away. 

 They are scarcely less destructive in this way than the black snakes, 

 though I have never known them to kill young birds." 



Behavior. — The two cuckoos are so much alike in haunts, habits, 

 and behavior that most of what I have said about the yellow-billed 

 would apply equally well to this species. The black-billed is rather 

 more SAvift on the wing than the other, but it flies in the same grace- 

 ful manner. It is the same shy recluse of the shady retreats, among 

 the dense foliage of the woods and shade trees, unafraid to frequent 



