Craig, Expressions of Emotion in Pigeons. 49 



modes of expression commonly follow one another, or alternate with 

 one another, in quick succession. Indeed the bowing-coo, instead of 

 being named thus, might well be called the coo-of-excitement. It 

 differs from the perch-coo, in regard to its use, in much the same way 

 as the kah-of-excitement differs from the ordinary-kah. The perch- 

 coo expresses moderate emotion ; the bowing-coo, excessive emotion. 

 The perch-coo, though heard more frequently from the male, is given 

 commonly by both sexes ; the bowing-coo, under normal circumstances, 

 is given almost exclusively by the male. The perch-coo is never 

 directly aimed at another bird ; the bowing-coo is always so aimed. 

 The other bird at which the bowing-coo is aimed may be another male, 

 whom the cooing bird wishes to fight or drive away ; or it may be 

 a female, in which case the cooing bird may be wooing, or expressing 

 affection, or driving the female away from other males, or (appar- 

 ently) merely asserting his mastery over the female. It is thus seen 

 that the bowing-coo, like the other expressions of excitement, does 

 not attach to any one emotion nor to any one type of the situation, 

 but is used in case of great excitement due to any cause whatever. 



As the name implies, the bowing-coo is accompanied by a bowing 

 movement ; the bird bending, at the beginning of each repetition of 

 the coo, to a perfectly prone position (Plate I, Fig. 6), and rising, 

 at the end of each, to an extremely erect position (Plate I, Fig. 5). 

 To speak more precisely, the downward movement is made with sud- 

 denness at the beginning of the first syllable of the "cook coor too, 

 goo oj" the prone position is maintained inflexilily during the first 

 two syllables ; the upward movement is made, somewhat less abruptly 

 than the downward niDvement, at the beginning of the last syllable, 

 "roo," the erect position is stiffly maintained during the last syllable 

 of the coo and the guttural "goo 0." While in the erect posture, the 

 dove lifts its feet, right and left alternately, high above the ground, 

 as if marking time. Its crop, during the whole performance, is 

 swelled out as in the perch-coo, or even more so. The feathers on the 

 head, neck, and breast, are smoothly appressed ; but the feathers on 

 the back are stiffly erected. This arrangement of the feathers reminds 

 one of the feather arrangement of the charge. 



The sound of the bowing-coo differs from that of the perch-coo in 



