VOICE AND INSTINCT IN PIGEON HYBRIDIZATION AND PHYLOGENY. 113 



"I think the kind of study of instinct that is much needed now is what I might call the morpho- 

 genesis of instinct. Instincts certainly did not arise suddenly; they are traceable back to simple 

 beginnings in the lower ancestors." (Conv. '08-'10, W. C.) 



VOICE AND INSTINCTS IN HYBRIDS FROM CROSSES OF SPECIES AND GENERA. 



In hybrids one finds intermediate behavior very well marked. Voice affords a most 

 striking illustration of the same thing. From a hybrid between two distinct species one 

 invariably obtains notes that are intermediates of those of both parents. Sometimes the 

 hybrid will begin with notes that are more nearly those of one parent and then break off 

 into those more nearly those of the other parent; in other words, it will exhibit a sort of 

 lack of coordination, a lack of equilibrium, if the term may be used there. The bird has 

 not complete control of its organs. (SS 10.) 



HYBRID BETWEEN A MALE ST. ALBA-RISORIA AND FEMALE SPIL. SURATENSIS. 



The "display coo" which is given in courting, or in threatening opponents, is delivered 

 in the manner and time of suratensis i.e., in the manner of both parent species and in a 

 time that is quicker than that of the ring-dove and possibly a little slower than that of 

 suratensis. It has a marked element of the rattling, rapid vibration which is so characteristic 

 of the Surate turtle ; but in this it stands midway between the two parent species. The male 

 ring-dove occupies about 2^ seconds in delivery of one display coo and passes continuously 

 from one coo into the next. 



The "nest-call" of this hybrid was timed with the following result: 



Repeated the call 19 times in one minute. 

 Repeated the call 18 times in one minute. 

 Repeated the call 14 times in one-half minute. 

 Repeated the call 10 times in one-fourth minute. 

 Repeated the call 10 times in one-half minute. 



The call is three-fourths to one second in length; the interval between calls varies. 

 Ten times in 15 seconds is the more rapid rate, with intervals averaging about one-half 

 second. It varies all the way from one-half second to 2 seconds in the above observations, 

 which were continued during 20 minutes. 



The call is of two syllables, but these flow together; the first is about one-half the length 

 of the second. The second syllable is a swell, but hardly rises in pitch above the first. The 

 sound is rather loud and harsh, having the vibrations of suratensis roughened so as to merit 

 the term harsh. The mode of delivery of this call is that of either parent; the bird getting 

 into the nest-box, raising the tail, and lowering the head close to the bottom of the box. 



In dropping one of the first two syllables, the hybrid makes an approach to the ring- 

 dove. The hybrid's call varies not only, as above stated, in length and rate of repetition, 

 but also in the quality of the tones, the relative measure of the syllables, in loudness, 

 degree of roughness, etc. In short, the call is far less even or regular than in a pure-bred 

 species. The nest-call of St. risoria is 2^ seconds long as a rule; it may be shortened to 2 

 seconds. 



This r'mg-suratensis hybrid mated, at the age of 22 weeks, with a female ring-dove and 

 gave opportunity to study its "note of sexual pleasure." The ring dove has a "laughing" 

 note after sexual union. The Spil. suratensis arches its neck and gives a peculiar, short 

 note, somewhat like the danger note, but expressive of intense pleasure. The same note 

 is given by Spil. chinensis, T. turtur, T. orientalis, and by my fertile hybrid from the common 

 pigeon and the Japanese turtle-dove. The ring-suratensis hybrid also gives this note in a 

 modified form. 



The mother of this hybrid is now (Mar. 19) mated with a male Spil. chinensis. Just 

 now I heard the sexual call of both. It is repeated several times by both the male standing 



