1916 J HvxhEY, Binl-initcliing and Biological Science. loO 



In all the species, the male arrives a week or more in advance of 

 the females; this week is spent in the acquisition of a definite 

 Territory, or sphere of influence; each cock probably returns to 

 the place where he was hatched and reared, and this inevitably 

 gives rise to disputes. From Mr. Howard's observations it is 

 quite clear that this "Territorial System" is here, as in many other 

 birds, of the greatest importance in the affairs of the species, and if 

 trespassing takes place, violent conflicts ensue until one bird is 

 in undisputed possession, which fact he proclaims by his song. 

 Then the females arrive; they too presumably re-traverse the 

 routes they followed southwards in the previous autumn, they hear 

 the songs of their mates, and come down to the nesting-sites thus 

 already staked out for them. It would appear that, while the 

 cocks fight for the occupation of a territory, the hens fight too — 

 for the right of entry into the territory once it has been gained by 

 the cock. In these female combats the cock seems to take very 

 little active interest, so that pairing-up is apparently scarcely 

 influenced at all by individual likes or dislikes (a primitive condi- 

 tion, and very unlike what occurs in the Grebe) — there is simply 

 an impulse to sing and so to attract mates in the male, in the female 

 an impulse to pair-up with any male in possession of territory. 

 It is only after this that "courtship" begins. Nest-building, 

 coition, and courtship all start almost immediately after pairing-up. 

 The courtship has the form of a display by the cock, who hops 

 about in front of the female in the display-position found in so 

 many birds, with head low and outstretched wings drooped and 

 extended, tail fanned and raised; often too he holds a leaf or twig 

 in his beak. 



The female will often remain absolutely unmoved by these 

 displays, feeding as unconcernedly as if the cock and his frantic 

 ecstasy were a hundred miles away; but when coition takes place 

 it seems to do so as a result of the hen being first in a receptive 

 condition, and then being stimulated by this display of the cock.'^ 



' Critics of such a view as that here adopted to explain the liabits of the Warbler, and 

 adopted in general by Pycraft ('13), would do well to remember that in all the higher ani- 

 mals the condilion of the brain very largely determines action. The cock is more eager 

 than the hen. Her mere presence will inspire him with the desire to pair, but only at 

 intervals; when this desire is present, he expresses it in the display actions. These actions 

 in their turn inspire the hen with the desire to pair — but again not every time that they 

 are exhibited. 



