232 THE BIRDS OF THE BRITISH ISLES. 



grass (Plate 102), looks as if a puff of wind would dislodge it 

 from its narrow base, but really it is a work of art. Both birds 

 collect material, which consists of clay and mud as well as 

 weed, and this, well trodden by the patient architects, forms 

 when dry a firm, almost solid foundation. During courtship, 

 nest building, and incubation the colony rings with pleasant 

 calls of kitti-waake^ kitti-waake, with an ascending emphasis 

 on the last syllable. 



Though there is frequent sparring between the various 

 occupants of a ledge, the paired birds are most affectionate, 

 caressing one another and expressing their feelings in head 

 and throat movements, which Mr. Kirkman rather happily 

 describes as " gulping." The male frequently feeds the female, 

 and takes a share in incubation. In the evening I have watched 

 the birds changing places, when many exchanges of compli- 

 ments and a cheerful volley of kitti-waakes accompany the 

 " relief." About the end of August the majority of old and young 

 are ready to depart, but for some time after that remain at sea 

 near the cliffs. The two or three eggs (Plate loS) are usually 

 lighter in ground — greyish, pale buff, or stone colour — than the 

 eggs of most gulls ; they are blotched and zoned with brown 

 and grey. The nestlings are also paler than those of gulls 

 which nest in more accessible situations ; their heads are 

 greyish white, and the marks on their grey backs are very 

 faint. The parent does not regurgitate and present the young 

 with food, but allows it to fish in its open mouth for what it can 

 find, after the manner of a Cormorant. 



In first plumage the crown and nape are grey and the back 

 and wings mottled with brown, but the "tarrock" dress is 

 acquired in the first autumn and retained for at least a year ; I 

 have seen birds in this plumage at the nesting colony. The bill 

 is then black and the legs much browner than in the adult bird. 

 The brown irides are surrounded in the young bird with a pale- 

 yellow eye-rim, but when mature this is red. The nape and 



