374 DISCOVERY REPORTS 



Phalacrocorax atriceps, King, Blue-eyed Shag. 



Blue-eyed Shags breed in colonies on a number of detached rocky islets throughout 

 the South Orkneys. No rookeries were found anywhere on the main islands. They are 

 probably most numerous round Laurie Island, where the Scotia Expedition estimated 

 the summer population to be about 2500 pairs. 



A large rookery is established on Holmen Gras Islet, just south of EUefsen Harbour, 

 and another on the southernmost of the Inaccessible Islands. On several islets the birds 

 share their rookeries with Ringed Penguins. Since the rocks are usually steep-to, the 

 Ringed Penguin is the only species which would choose to nest on them. In the Palmer 

 Archipelago shags are found sharing their rookeries with Gentoo Penguins. 



The rookery on Holmen Gras was visited on January 5. The nests all contained two 

 or three chicks, varying in age from a few days to about a fortnight. The chicks are com- 

 pletely bare at birth, the skin of the back being brown-black, and of the underparts 

 pink. After a few days they are covered in brown-grey down. In the chicks the bill is 

 mainly brown, the lower mandible being pinkish bluish at the base, shading into brown 

 at the tip. 



In the adult birds the bill is dull grey-brown, the lower mandible being paler at the 

 tip. The feet are pinkish, turning into brown-black at the edges of the webs. The birds 

 had lost their nuptial crests at this time, and the caruncles were faded yellow. 



On January 5 when a survey party was landed on the beach of a small bay on the 

 western side of Fredriksen Island, a flock of shags came swimming slowly in from the 

 northward, approached to within a few yards of the shore and moved off to sea. The 

 flock was in perfect arrowhead formation and the birds were closely packed in the flock. 

 There were about two hundred of them, and as they swam slowly along with only their 

 snake-like heads and necks showing above the water they presented an extraordinary 

 spectacle. It was considered likely that these birds were from some near-by colony, 

 possibly Holmen Gras, on a foraging expedition, and that they were attracted towards 

 the beach by the presence of the boat. 



On January 26 a rookery on the islet on the western side of Wilton Bay, in Laurie 

 Island, was visited. About 180 nests are established here. The young were all in first 

 plumage and had left the nests. They wandered about the rookery, which was in a very 

 filthy condition, and when disturbed showed little inclination to take to the sea. A few 

 of them swam, but it was evident that they were not yet proficient in the water. These 

 birds were considered to be six or seven weeks old, and at this stage the caruncles are 

 not developed, the eyelids are greyish without a trace of blue, and the legs and feet 

 are grey-brown, with pinkish patches in the webs. The bill is similar to that of the chick. 



The Scotia Expedition saw only a few birds during the winter. It is suggested that 

 the majority migrate to the Patagonian Islands, for on April 15, 1930, a number of shags 

 were observed near the ship in a position 1 50 miles south-south-east from Cape Horn. 

 These were definitely P. atriceps, and it seems likely that they were Antarctic birds on 

 migration, for it is improbable that birds from Tierra del Fuego would stray so far 

 afield. 



