208 SEA-BIRDS 



should maintain a watch throughout the critical months of nest-building 

 and incubation and the period of the chick's helplessness. 



Displaying paired gannets stand face to face, the wings half open 

 and the tail depressed; the head and the wings are waved, the bills 

 clashing, rattling and colliding like castanets. This astonishing mutual 

 display may continue for minutes, with short pauses. It is varied by 

 one of the pair curtseying, but as there is already little room for two 

 birds on the narrow pedestal nest, the performer sometimes loses 

 balance in an undignified manner. The curtsey is best seen when the 

 performer is alone at the nest — and the individual, without or with 

 egg or chick, frequently indulges in this peculiar, graceful, and digni- 

 fied ceremony. The head is thrust underneath the body or one wing 

 with a serpentine movement, and next thrown high in the air and 

 shaken to and fro, usually to the accompaniment of strident urrah 

 cries. This performance is usually repeated in a sequence of three 

 curtseys. Another activity is the picking up of apiece of nesting material, 

 which is held in the bill, shaken, and sometimes tossed into the air 

 and caught again as if it were a fish. Probably most of these motions 

 (except the billing) are derived from actions used in diving for, catch- 

 ing, tossing up and turning, fish. Gannets do not feed each other 

 at the nest, but they have been observed to pass seaweed from one 

 to another during mutual billing. 



When about to take ofif from the gannetry the individual usually 

 adopts a special posture, not unlike that of the male pelican when 

 changing duty at the nest. It may be associated with the filling of the 

 subcutaneous cells with air. The neck is stretched out until the beak 

 points upwards at right angles to the ground, and the bird marches 

 towards the edge of the colony, the wings slightly open, the whole 

 attitude suggesting fear of attack from the bills of neighbouring birds; 

 to the human observer this fear seems perfectly justifiable — if the 

 marching bird passes within striking distance of a sitting gannet it 

 is at once attacked. When the site of the gannetry is on level or fairly 

 level ground, and there is no easy take-off from the cliff-edge, the 

 posturing gannet turns round and round on the nest before suddenly 

 launching itself into the air. But this leap may not be successful; 

 the bird may crash into the ranks of its neighbours, and will then 

 receive a severe drubbing from their beaks as it blunders down towards 

 the sea. 



The coition of all pelicans takes place on the nest. The male 

 gannet grips the golden head of the female in his bill; as a result it is 



