V01 ' 1920 XVH ] Townsend, Courtship in Birds. 389 



Let me describe a typical performance: As the sexes are alike 

 in plumage they cannot be distinguished apart. One of them, 

 we will assume it is the male, is swinging around in great circles 

 on rigidly outstretched and motionless wings. He passes within 

 a few yards of me and swings towards a shelf crowded with birds 

 brooding their downy, black-faced young. Alighting on the edge 

 he elbows his way along the ledge, notwithstanding the angry 

 looks, the black mouths suddenly opened and the vicious pecks 

 of his neighbors. All of these he returns in kind. Arrived at 

 his nest he is enthusiastically greeted by his mate, who, disre- 

 garding the young bird beneath her, rises up to do her part in the 

 dance. The birds stand face to face, the wings slightly raised and 

 opened, the tails elevated and spread. They bow towards each 

 other, then raise their heads and wave their bills as if they were 

 whetting these powerful instruments, or as if they were perform- 

 ing the polite preliminaries of a fencing bout. From time to time 

 this process is interrupted as they bow to each other, and appear 

 to caress each other as each dips its pale blue bill and cream- 

 colored head first to one side and then to the other of its mate's 

 snowy breast. With unbated enthusiasm and ardor the various 

 actions of this curious and loving dance are repeated again and 

 again and often continue for several minutes. After the dance 

 the pair preen themselves and each other, or the one first at the 

 nest flies away and the new arrival waddles around so as to get 

 back of the nestling, and the strange process of feeding takes 

 place. 



This dance is not only performed by pairs as just described, 

 but not infrequently individuals perform a yas seul, it may be 

 because he or she is wearied with waiting for its mate. The 

 wings are slightly raised and opened, the tail elevated and spread, 

 the bill pointed vertically upwards and waved aloft, then dipped 

 to one side under the half open wing and then to the other, the 

 bill raised and waved again and so on over and over again. Owing 

 to the great volume of sound from the ledges it is impossible to 

 distinguish any individual performer, and I was unable to tell 

 at what point in the dance and to what extent the song was im- 

 portant. The sound is like that of a thousand rattling looms 

 in a great factory, a rough, vibrating, pulsing sound — car-ra, 

 car-ra, car-ra. 



