THE BLACK-BILLED CUCKOO. 29 



the eggs of both species, and have come to the conchision that I was not mis- 

 taken in that observation. On September 10, 1883, 1 found a nest of the Black- 

 billed Cnckoo containing two young birds not more than one day out of the 

 shell; the two previous nights we had severe frosts that destroyed vegetables." 



While instances of the Black-billed Cuckoo laying in the nests of the 

 Yellow-billed are not especially rare, cases where it lays its eggs in those of 

 other species, especially smaller ones than itself, are decidedly uncommon. I 

 have never seen a case of this kind, but, nevertheless, several well-authenticated 

 instances have been recorded which leave no room for doubt; of these I will 

 only quote one, published by Dr. C. K. Clarke, of Kingston, Ontario, Canada, 

 who says: "In an orchard we discovered a Black-billed Cuckoo sitting in a 

 Chipping Sparrow's nest, and the bird did not attempt to move till we almost 

 touched it. It now seemed very evident that the case against the bird was a 

 strong one, and when a Cuckoo's egg was found in the nest the chain of evi- 

 dence was complete. The egg was hatched and produced a tyrannical young 

 Cuckoo, who turned his companions out of the nest and made himself as com- 

 fortable as jiossible as long as was necessary. Two of us saw the old Cuckoo 

 actually sitthig in the nest, and there was no doubt about the matter. We have 

 been informed that the erratic nesting of the Cuckoo has been repeated in the 

 same orchard since the occasion referred to, but of this we have no accurate 

 information."^ 



Its e^ffs have been found in the nests of the Wood Pewee, Yellow Warbler, 

 Catbird, and others. Nidification commences rather late, rarely before the 

 middle of Ma}'; full sets of eggs are sometimes found about the end of this 

 month, but much more frequently during June and July. Occasionally a set is 

 met with in the latter part of August, probably a second clutch. The earliest 

 nesting record I know is one of May 7, 1878, where Mr. Robert Ridgway found 

 a set of these eggs near Mount Carmel, Illinois; these are now m the United 

 States National Museum collection. Ordinarily an egg is deposited daily until 

 the set is completed, but not ixnfrequently they are laid at considerably longer 

 intervals, and it is well known that young of different ages, as well as eggs in 

 various stages of incubation, are sometimes found in the same nest. 



The nests of the Black-billed Cuckoo appear to be slightly better built 

 than those of the Yellow-billed species; the platform is usually constructed of 

 finer twigs, the soft inner bark of cedar, fine rootlets, weed stems, etc., and there 

 is generally more lining. This consists of the aments of oak, white and black 

 ash, andtuiaple, willow catkins, and the flowers of the cudweed or everlasting 

 (Gnajihalium), dried leaves, and similar materials. The majority of the nests are 

 placed in rather low situations, mostly not over 6 feet from the ground, on 

 horizontal liiiiljs of bushy evergreens, pines, cedars, and hemlocks, or in decid- 

 uous trees and shrubs, such as the box elder, chestnut, thorn apple, and beech 

 trees; also in hedges, briar and kalmia patches, occasionally on old logs, and 

 now and then even on the ground. Dr. P. L. Hatch reports such instances in 



' Transactions of the Canadian Institute, Oct., 1890, Vol. I, Part 1, pp. 48-50. 



