454 STEBCOEARIID^E STEBCORARIUS 



tail ; acuminate feathers of the neck streaked with golden-straw 

 colour ; outer primaries with white shafts. In the white-breasted 

 form there is more or less white on the hind neck, chin, breast 

 and abdomen. 



Bill brownish-horn, darker in front of the cere, legs black. 



Length about 18-0 ; wing 11-5 ; tail 4-5, to end of central tail 

 feathers up to 8'0 ; culmen 1-3 ; tarsus 1-85 ; middle toe and claw 

 1-70. 



Young birds are brown above, often mottled and streaked ; 

 upper tail-coverts barred with dark brown, white and rufous ; the 

 under surface white barred with brown. 



Distribution. Kichardson's Skua has a circumpolar range, 

 during the northern summer breeding as far south as Scotland. 

 During the northern winter it migrates southwards to Eio do 

 Janeiro and the Cape, along the Atlantic seaboards, to the Persian 

 Gulf in the Indian Ocean, and to New Zealand waters and Cali- 

 fornia in the Pacific. 



Within our limits this bird has been noticed in Walvisch Bay 

 by Andersson, who states that it is not at aH uncommon during 

 certain seasons of the year ; it is found in Table Bay during the 

 summer (October to March), and Mr. J. G. Brown informs me that 

 he has shot a specimen in Algoa Bay. 



Habits. Richardson's Skua is remarkable for presenting, irres- 

 pective of sex, two very distinct phases of plumage, one sooty- 

 brown throughout, the other dark above and white below. Birds 

 of both phases pair with one another indiscriminately where they 

 meet, and the young are sometimes intermediate. Mr. Saunders 

 seems to think that the darker birds are more southerly in their 

 range, but there are examples of both varieties, in the South 

 African Museum obtained in Table Bay. 



This bird is almost parasitic in its mode of life ; it seldom fishes 

 itself, but constantly chases the lesser Gulls and Terns and com- 

 pels them to disgorge their prey. So active is the Skua that it 

 usually manages to catch the fish as it falls from the bill of the 

 Gull before it reaches the surface of the water. 



Mr. Andersson states that this Skua chiefly frequents the 

 shallows and lagoons along the coast ; it is not known to breed 

 in South Africa, and probably will not be found to do so. In 

 Scotland its nest is found inland in a hollow in heather or moor- 

 land grass. Two eggs are laid of a greenish-brown colour blotched 

 with dark brown. 



