442 STERNIDiE STERNA 



766. Sterna macrura. Arctic Tern. 



Sterna birundo, Linn. Syst. Nat 12th ed. i, p. 227 (1766) [in part] 



Sharpe and Dresser, B. Eur. yiii, p. 255, pi. 579 (1872). 

 Sterna maorura, Naum. Isis, 1819, p. 1847 ; Gurney, Ibis, 1868, p. 262 ; 



Saunders, P. Z. S. 1876, p. 650; Butter, Feilden and Eeid, Zool. 



1882, p. 428 ; Sharps, ed. Layard's B. 8. Afr., p. 701 (1884) ; 



Saunders, Cat. B. M. xxv, p. 62 (1896) ; Shelley, B. Afr. i, p. 163 



(1896) ; Beichenow, Vog. Afr. i, p. 63 (1900) ; Shortridge, Ibis, 1904, 



p. 203. 

 Sterna brachypus, Swainson, B. W. Afr. ii, p. 252 (1837) ; Layard, 



B. 8. Afr. p. 371 (1867). 



Description. Adult. — Closely resembling S. Jluviatilis, but 

 easily distinguished by the narrowness of the dark bands on the 

 inner webs of the outer primary ; these are only about -12 to '15 

 inch wide instead of '25 to -30 ; as a rule, too, the tarsus is shorter, 

 not exceeding the middle toe without claw, while the reverse is the 

 case with S. fluviatilis. 



Bill blood-red ; legs coral-red. 



Length about 13-0; wing lO'O ; tail 7-0; depth of fork 4-0; 

 tarsus -65 ; middle toe without claw -65. 



Distribution. — The Arctic Tern has a more northerly range than 

 the Common Tern ; it breeds in the circumpolar regions of both the 

 Old and New World down to about 50° N. in Europe and Asia, and 

 42° N. in America. During the northern winter it is found about 

 the coasts of South America and South Africa, and even further 

 south in the Southern Ocean. 



As the following list of South African localities shows, this Tern 

 is by no means confined to the coast, or, indeed, to the mouths of 

 rivers : Cape Colony — Table Bay, August, and Tulbagh, breeding 

 dress (Layard), Graaf Eeinet, breeding dress, Heidelberg, October, 

 non-breeding, Kentani Transkei, June, non-breeding, Port St. John's, 

 June, non-breeding (S. A. Museum) ; Natal — Newcastle, November 

 (Giffard). 



767. Sterna balaenarum. Damara Tern. 



Sternula balaenarum, StricTcland, Contr. Orn. 1852, p. 160 ; Qurney, in 



Andersson's B. Damaral. p. 363 (1872). 

 Sterna balaenarum, Saunders, P. Z. S. 1876, p. 664 ; Sharpe, ed. 



Layard's B. S. Afr. p. 705 (1884) ; Saunders, Cat. B. M. xxv, p. Ill 



(1896) ; Shelley, B. Afr. i, p. 163 (1896) ; Beichenow, Vog. Afr. i, 



p. 68 (1900). 



