80 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



Voice. — One cannot ahvays distinguish with certainty all the notes 

 of the black-billed cuckoo from all those of the yellow-billed. Many 

 of the notes are much alike in both species. The notes of the black- 

 billed are, as a rule, softer and more liquid than those of the yellow- 

 billed and not so deep-toned. 



The ordinary "song" of the black-billed is preceded by a gurgling 

 note, and the rest of the long song is uttered in regularly measured 

 time, not retarded at the end, as is that of the yellow-billed, and the 

 notes are given in couplets or triplets, one syllable in each set being 

 accented. Dr. Charles W. Townsend (1920a) describes it very well 

 as follows : "The full song may be described as a preliminary harsh 

 clearing of the throat followed bj'^ from six to twelve short coughs 

 which in turn are succeeded by the more pleasing doublets and trip- 

 lets of cows. The Yellow-billed Cuckoo repeats his cotvs or cowks in 

 regular order without dividing them into sets and they sound as 

 woodeny as if he were striking a plank with a mallet." 



Aretas A. Saunders (1929) says: "The bird has a variety of calls. 

 One consists of a gurgling note followed by single notes in even 

 time, 'krak-ika kuh kuh kuh kuh kuh kuh kuh kuh'. Another is a 

 series of groups consisting of two to six notes repeated many times, 

 with one of the notes strongly accented, such as ^kuksi kuksi kuka,'' or 

 ^kakukaku ka^^^aka kakukakii.^ I have known a bird to repeat 

 such phrases over a hundred times without stopping." 



The notes of the black-billed cuckoo are often given on the nest or 

 while the bird is in flight, and they may be heard at all hours of the 

 day or night. Both cuckoos are said to be more noisy just before a 

 rain, hence the name "rain crow." 



Mr. Brewster (193Ta) says that "both species coo in the same sub- 

 dued, mournful, dovelike tones, but when so engaged, the Yellow- 

 bill always utters only a single note at a time, and then waits at least 

 a second or two before following it with another precisely similar; 

 whereas the cooing notes of the Black-bill are invariably doubled or 

 trebled or quadrupled, or perhaps even quintupled, yet separated 

 from one another within such grouping by scarcely appreciable 

 pauses." 



Gerald H. Thayer (1903) has given an interesting account of what 

 he calls "the mid-summer, mid-night, mid-sky gyrations of the Black- 

 billed Cuckoo, as noted by my father and me for three consecutive 

 seasons in the southwestern corner of New Hampshire": 



Several years before we discovered the noeturiuil-flight pUeuomenon, we 

 began to be puzzled by the extreme frequency of Cuckoo calls on summer 

 uights. * * * They uttered both the coio-cow notes and the rolling guttural 

 call ; but the guttural was much the commoner of the two, except on dark. 

 foggy nights, when the case was usually reversed. * * * rjij^g birds were 

 often so far up as to be only faintly audible when directly overhead, with no 



