114 BEHAVIOR OF PIGEONS. 



still, the female often walking around him, back and forth, two or three times, while repeat- 

 ing the call. The first repetition is quite loud and fairly rings out; the later ones gradually 

 diminish in force. This call is given with beak closed and is an orgastic grunt, similar to 

 the danger-note, but with far greater emphasis and delivered with great gusto. 



The "perch-call" is the call in which this bird best displays the lack of fixed adjustment 

 in its vocal organs. So much does the bird's voice vary in pitch, rhythm, quality, loudness, 

 etc., that he often appears like a bird practicing trying to use his organs but unable to 

 make two calls precisely alike. His voice-machinery seems to wobble up and down, from 

 side to side. The voice is now hoarse, now relatively smooth, now monotone, now dis- 

 syllabic, with a strong swell on the second syllable. 



The greatest variation seems to be in passing from one syllable to the next, the voice 

 fairly rattling or gurgling at times. In all this variation, the departures are never very 

 wide. There are two syllables, generally suggesting coo-ooo, in which the second is a swell 

 more or less strong, and marked with a vibration that reminds one of that of the mother 

 species; but the vibration here is weaker, i.e., it is less marked. Sometimes the call comes 

 nearer caw-aw. 



In delivering the call the bird swells out the neck so as to show its neck-spots best on 

 the swell. It opens its mouth slightly at the beginning (inhaling), holds the head nearly 

 still, but throws it forward and upward about one-fourth inch when it begins the call. In 

 repeating, the head may move a little or not at all, according to the vigor of the call. If 

 the call is loud, then the one-fourth inch movement is seen. The call is three-fourths to 

 1 second long. The swell is somewhat the longer part. 



The "warning or fighting note" of this hybrid is given when he drives his mate or 

 threatens another dove through the wire. The male ring-dove has a peculiar laughing 

 note for this, to which the hybrid's note seems related. (R 14.) 



MALE HYBRID BETWEEN A MALE BLOND RING AND A FEMALE JAPANESE RING. 



The "nest-call" is repeated three to four times in .the course of 10 seconds; each call 

 occupies 1^ to 2 seconds, the interval (shorter ones) is 1 second or a fraction less. The call 

 is of two syllables or three. If not answered it may rise to four, the same as in the "perch- 

 call." In the nest-call the first syllable is short; the second is prolonged with swell and a 

 slight rattle or rolling sound of r; the third syllable is cut quite short and abrupt. The call 

 is low in pitch, rather hoarse and growl-like. 



A male St. douraca (Japanese ring) was kept alone in a pen in the house for a month or 

 two so that I could compare his cooing with that of the hybrid. The pure ring gave his 

 call at intervals of a few minutes loud, full, clear, smooth. The hybrid's call had the 

 same number of syllables, delivered in about the same time and inflections, but his voice 

 was decidedly harsh and far less pleasant to hear. It was not so loud and far-going as that 

 of the pure bird. 1 



After counting and timing many instances of the perch-call or song of St. douraca and 

 of the hybrid, the author came to the conclusion that the "hybrid keeps up his calls for a 

 longer time." That is, the hybrid gives an average of 10 calls in each continuous series; 

 St. douraca gives only about 8. 



THE VOICE OF RING DOVES. 



The "nest-call" of female blond rings is a short coo followed by a trill. Indicated thus: 

 Coo-r-r-r-r-r-r-oo. The whole occupies about 1^ seconds. The coo and the final oo are of 

 about the same duration, and each occupies not over one-tenth of a second, the remainder 

 of the time being used in the trill. 



1 That is to say, the voice of the hybrid is more hoarse than that of either parent species. EDITOR. 



