Craig, E.xprrssions of Emotion in Pigeons. 67 



to sexual inactivity in winter; and birds maturing in the spring are 

 accelerated, in comparison, by the tendency to begin breeding in 

 spring. 



The autumn and the early winter are marked not only by inac- 

 tivity in breeding but also by disuse of the voice ; at least a disuse 

 as compared with its copious use at other seasons. 



But as winter advances, long before warm weather has definitely 

 set in, a change toward the musical life is noticeable. The voice 

 is used more and more, and it gradually regains the volume of sound 

 and perfection of form which characterize it in spring and summer. 

 Whether the preliminary exercise of the voice aids at all in its devel- 

 ojjinent, it would be difficult to say. The fact is that the perfection 

 of the voice and the tendency to use it arise gradually and coinci- 

 dentally; and it seems probable that each aids the other. Yet there 

 are reasons for believing that practice has very little effect in de- 

 veloping the voice of the dove. 



As the birds begin to coo, they naturally begin to coo to each other ; 

 and while the whole pigf'onry bombards the ear with an abundance 

 of sounds, each pen presents to the eye an abundant spectacle of 

 bowing and charging, wooing and fighting, love and jealousy. This 

 may continue a long time before each bird secures a mate. But, to 

 notice in detail the formation of a union between two birds, it is 

 more convenient to st\idy the case of two ring-doves isolated in cages. 



If a cage containing an unmated male ring-dove be suddenly 

 brought alongside another cage containing another ring-dove, of un- 

 kno^\Ti sex, the male becomes highly excited at ouce, and gives vent 

 to his excitement in all possible ways. First he bows and coos with 

 all his might, and he continues to do so for a long time. Then he 

 charges about the cage, assuming the attitude peculiar to the charge, 

 and frequently repeating the loud kah-of-excitement. At intervals 

 he stops to glare at the strange bird and sometimes to peck at it 

 through the bars, but soon he starts again to bow-and-coo and charge. 

 After more or less of this display of aggressive impulse, he begins 

 to show eros, by a certain spasmodic preening of the inside of the 

 wing (a movement which invariably accompanies erotic activity), 

 and \)\ assuming' the nest-callinc; attitude and soundino; the nest-call. 



