VOICE AND INSTINCT IN PIGEON HYBRIDIZATION AND PHYLOGENY. 117 







other times, in a little over 5 seconds. Each call is a full second long; it consists of two 

 syllables, which flow together so evenly that they seem like one monotone at a distance of 

 a few yards. The first syllable is a short coo, and the second is most nearly the sound of 

 oo in coo, but prolonged in a swell that rises slightly in pitch above the initial sound, falling 

 at the end. The two syllables flow together without any break. The tone is a little rough, 

 but is fairly smooth in some individuals. It is a rather loud call louder than that of the 

 mourning-dove, and not so pleasant. Heard in the house, at a distance of one floor (below), 

 it sounds like a moan of some one in distress. It is something more mournful than the 

 notes of the mourning-dove. 



The nest-call of Zenaidura is the same dissyllable, in which the two syllables are plainly 

 distinct, even at any distance in the house. The first part is longer proportionately than 

 in the hybrid, and the second part is a smoother and more marked swell. 



In one count, the "perch-call" was repeated 17 times in 20 seconds, and in quite even 

 time. Frequently the call is repeated about once per second. This prolonged repetition 

 (which occurs also in the Ectopistes X risoria hybrid) does not come from the father (see 

 perch-call of Zenaidura below). It is probable that it comes mostly or wholly from the 

 mother, since St. risoria repeats its perch-call in rapid succession. The call is more distinctly 

 of two syllables, and a little higher in pitch as well as smoother and more agreeable, than the 

 nest-call. The same letters, coo-oo, may be used to express this call, although it is quite 

 different in quality of tone and manner of delivery from the nest-call. The bird stands in 

 normal pose head up and tail drooping naturally. 



Another of these male hybrids exercises his perch-call very freely. His voice is quite 

 full and smooth and far-reaching, telephonic. He repeats the call sometimes as many as 

 15 times in about 15 seconds; sometimes only 5, 7, or more times, averaging nearly 1 call 

 a second, the calls following one another in continuous strain. The pause between the 

 strains may be only a few seconds, or 15, 30, or longer. But the strains are heard fre- 

 quently in the morning hours, between dawn and 9 to 10 o'clock, and then again towards 

 evening. 



One of these hybrids gives the call in a loud monotone in which two syllables are hardly 

 recognizable. It sounds like blowing over the lip of a bottle-neck, and reminds me of the 

 call I have heard from the Wonga Wonga pigeon (Leucosarda) . But the call of the latter 

 is very much less loud and is softer. 



In sexual union the male hybrid shakes his feathers like the male Zenaidura, but 

 not so persistently or so vigorously as a means of getting the attention of his mate when 

 he is about to offer his bill. He opens his bill to receive that of his mate, and seems prone 

 to repeat this several times before mounting. In case the female offers herself he frequently 

 declines, again offering his bill, so as to excite her more before mounting. When he mounts 

 he hurries, executes the act very quickly, in the manner so characteristic of Zenaidura. 

 St. risoria acts decidedly slower. 



After copulation, when the male has resumed his place beside his mate, he arches his 

 neck and gives a short grunt, the "note of sexual pleasure," which is not quite so loud as 

 in Zenaidura. It is the note so characteristic of the turtle-doves, and the note which is 

 also given by the wood-pigeon (C. palumbus). This bird has refused to mate with ring- 

 doves, either white or blond ; but he is very eager to mate with a female Zenaidura as soon 

 as I put her near him. Other of these hybrids prefer ring-doves. 



Both mourning-doves and these hybrids, when walking about on the floor of their pen, 

 or when on the perch, give the tail an upward toss now and then. I noticed that this motion 

 is not made when flying up and alighting, as it is in Spil. ligrina, but always (?) in correlation 

 with a head-movement; i.e., if the bird is looking at you and from fear, excitement, or 

 what not, gives its head the peculiar back-and-forward motion it is almost sure to follow 

 it with a toss of the tail, this toss carrying the tail 1, 2, or 2.5 inches high. 

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