82 BIRD WATCHING 



leaving his own mate to guard their chosen ground ; 

 and instead of resenting this visit as an unwarranted 

 intrusion on their domain, as they would certainly 

 resent the approach of almost any other bird, they 

 welcome it with notes and signs of pleasure. Ad- 

 vancing to the visitor, they place themselves behind 

 it ; then all three keeping step begin a rapid march, 

 uttering resonant drumming notes in time with their 

 movements, the notes of the pair behind being emitted 

 in a stream, like a drum-roll, while the leader utters 

 loud single notes at regular intervals. The march 

 ceases ; the leader elevates his wings and stands erect 

 and motionless, still uttering loud notes; while the 

 other two, with puffed-out plumage, and standing 

 exactly abreast, stoop forward and downward until 

 the tips of their beaks touch the ground, and, sinking 

 their rhythmical voices to a murmur, remain for some 

 time in this position. The performance is then over, 

 and the visitor goes back to his own ground and 

 mate, to receive a visitor himself later on." 

 . Now the most curious point in this remarkable 

 performance, so well described, is that three birds — 

 a pair (male and female), and one other, whether male 

 or female is not stated — take part in it, and how is 

 this fundamental peculiarity to be explained better on 

 the theory of "a universal joyous instinct" than on 

 that of sexual selection, if, indeed, the former one helps 

 us so well ? Joy, no doubt, is there, but something else 

 — some shaping force — is surely required to account 

 for the particular form in which it finds expression. 

 Now with regard to the peculiarity pointed out — the 

 odd bird (though all act oddly) — I have, whilst 

 watching birds in the early spring, been struck by the 



