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ON A LITTLE-KNOWN STATE OF PLUMAGE 

 OF THE ARCTIC TERN (STERNA MACRURA Naum,). 



HOWARD SAUNDERS, F.L.S., F.Z.S. 



Mr. W. Eagle Clarke has kindly presented me with a specimen 

 of the Arctic Tern {^Sterna macrura Naum.) in a state of plumage 

 not often obtained. It was shot at Spurn Head, Yorkshire, in 

 July 1884, and is evidently a bird hatched in the summer of 1883. 

 In their dried condition the bill, legs, and feet are nearly black (the 

 webs of the latter livid) ; the forehead white, the crown streaked with 

 black, and the nape almost entirely black. The upper parts are grey 

 as in the adult, except for a dark mottled line indicative of immaturity 

 along the lesser wing-coverts, and the darker tints of the tail feathers, 

 especially on the outer webs ; the entire under -parts are pure 

 white. In this plumage a similar specimen, which I examined 

 when in America, was described as a new species under the 

 name of Sterna portlandica, by Mr. Ridgway, of Washington, 

 ('American Naturalist,' viii, p. 433, 1874), but the author has long 

 since relegated this name to the list of synonyms of the Arctic Tern.. 

 Incidentally it may be mentioned that American ornithologists have 

 decided upon adopting the loth edition of Linnseus's ' Systema 

 Naturae' (1758), as their starting point, instead of the 12th (1766); 

 the result being that they call the Arctic Tern S. paradiscea Briinnich 

 (1764); and as Keyserling and Blasius have appHed the same name 

 to the Roseate Tern, an element of confusion is thereby introduced 

 in this case, as in a great many others. To return to the question of 

 plumage : the mottled garb of the first autumn is well known, but after 

 the young birds have left the immediate vicinity of our shores, very 

 little is seen of them until they return in the second spring in 

 breeding plumage. This intermediate stage is, therefore, seldom 

 observed, and I have only seen five or six. Another American 

 synonym for this species is S. pikei. The winter range of the 

 Arctic Tern is very extensive, reaching to Table Bay, and even to 

 the south-east of Madagascar on the one side ; and to Arica, in 

 south-western America on the other. The former brings it within a 

 measurable distance of the Islands of St. Paul and Amsterdam, in 

 about 38° S. lat. in the Southern Ocean, the home of the very closely 

 allied S. vittata. This species reaches westward to Tristan d'Acunha, 

 and southward to Kerguelen, in about 50° S. lat., where it meets 

 with a much darker species, S. virgata, confined, so far as we know 

 at present, to that island. If any reader of the above will enable me 

 to learn which of these two species is found on the more western 

 Crozettes, Marion, and Prince Edward Islands, he will lay me under 

 a great obligation. 



Dec. 1887. 2 A 



