STERNIDiB STEENA 441 



Swinbui-ne, Proc. B. Pliys. Soc. EcUn. ix, p. 200 (1886) ; Saunders, 

 Cat. B. M. XXV, p. 54 (1896). 

 Sterna dougalli {nee Mont.) Layard, B. 8. Afr. p. 369 (1867). 



Description. Adtdt Male. — Forehead, crown, nape and upper 

 lores black ; rest of the upper surface pearly-grey, outer primary 

 ■with a black outer web, a white shaft, outer half (about '25 to '30 

 in. wide) of the inner web dark ashy, inner half white, the white 

 disappearing some distance from the tip ; inner primaries more 

 silvery, with white wedge-shaped marks on the inner webs and dark 

 grey inner margins ; rump and tail whitish ; the outer webs of the 

 tail-feathers, especially in the case of the streamers darker grey ; 

 below including the cheeks white, slightly tinged with pale grey 

 on the breast and abdomen. 



Iris dark brown ; bill coral-red ; legs coral-red. 



Length about 13-0 ; wing 10-5 ; tail 6-0 ; depth of fork 3-0 ; 

 culmen 1'35 ; tarsus -76 ; middle toe without claw -65. 



The sexes are alike ; in non-breeding plumage the forehead and 

 crown are white, more or less mottled with black, the nape retains 

 more black ; the colours of the bill and feet are duller. 



Distribution. — The Common Tern is found along the coasts and 

 about the inland waters of Europe and temperate Asia and the 

 eastern half of temperate North America ; it migrates south to 

 India, Africa and Brazil during the northern winter. 



In South Africa the Common Tern has been hitherto met with 

 only along the coast from "Walvisch Bay to East London. 



The following are recorded localities : Walvisch Bay, October, 

 November (Andersson), Table Bay, all the year round (Layard), 

 Port Elizabeth, common (Brown), East London (Riokard). 



Habits. — The Common Tern is fairly abundant about the shores 

 of Table and False Bays, and though generally considered to visit 

 Africa during the northern winter, is, according to Layard, to be 

 found here all the year round. There are, in the South African 

 Museum, examples apparently referable to this species, in non- 

 breeding plumage, obtained in June and July in Table and False 

 Bays when one would have expected all the birds to be breeding 

 in the northern hemisphere, while one procured by Mr. Layard in 

 full breeding plumage has no date attached. However this may be, 

 this species has not been hitherto detected breeding here in South 

 Africa, and until more observations are recorded it is difficult to give 

 a satisfactory account of this bird's movements. 



