COURTSHIP IN BIRDS 267 



that Fisher did in the ease of the Layson 

 albatross, namely that it was originally a eourt- 

 ship dance and that it was continued from habit 

 and from joy of it, in the same way that the song 

 sparrow continues to sing long after the nuptial 

 season. 



Let me describe a typical performance: As 

 the sexes are alike in plumage they cannot be dis- 

 tinguished 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, notwith- 

 standing the angry looks, the black mouths sud- 

 denly opened and the vicious pecks of his neigh- 

 bors. All of these he returns in kind. Arrived 

 at his nest, he is enthusiastically greeted by his 

 mate, who, disregarding 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 



