118 Sketches of Some Common Birds. 



cuckoo architecture I ever found, the work of a yellow- 

 billed cuckoo, was made of sticks and roots of weeds, in- 

 terwoven with which were dried corn-husks, grapevine 

 bark, and dried leaves. The cavity was three inches 

 across and one inch deep. I took this nest and its three 

 eggs, and five days later I found a new structure near the 

 location of the first, containing two fresh eggs. This 

 second nest was made of twigs and many stalks of the 

 bloom of Indian corn, and a bunch of corn silk two inches 

 thick for bedding. The materials were close at hand 

 along the hedge. This may be called energetic work even 

 for species less dilatory than the cuckoos. 



The eggs of the yellow-billed cuckoo are light green in 

 color, and average in size .90 by 1.30 inches, varying 

 much, however, in different complements and in different 

 eggs of the same set. The eggs of the black-billed cuckoo 

 are a darker greenish hue, and average .80 by 1.10 inches, 

 exhibiting the same variations in size as those of its 

 relative, so that generally the eggs of the two species can 

 not with certainty be distinguished by size. The number 

 in a complement varies from one to six, though three and 

 four are the usual numbers. I have frequently found the 

 cuckoo industriously incubating a single Qgg which was 

 ready to hatch, and again a friend of mine once found a 

 , nest containing six eggs which were nearly fresh. 



The cuckoos when incubating are either fearless or 

 unsuspicious of danger, as they can usually be approached 

 by a cautious observer to within arm's length, thus allowing 

 positive identification of the species. The yellow-billed 

 cuckoo may be known by its having the lower mandible, 

 except the tip, yellow, as well as the cutting edges of the 

 upper mandible, while the black-billed species has the 

 bill entirely black. When approached from behind, the 

 bii'd on its nest closely resembles the mourning dove, the 

 long tail with white under parts and the carelessly built 

 nest furthering the resemblance. Frightened from its 

 nest by the motions of the intruder or by other means, 

 the bird glides silently to a neighboring branch, and soon 

 betakes herself away with low, even flight. No noisy 

 fluttering about the spot nor other signs of apprehension 

 mark the actions of these singular birds, as is usual with 



