ARCTIC TERN. 369 



could easily be distinguished from the Sterna Hirundo, first by their 

 smaller size, shorter tarsi, more delicate bill, and greater curvature of the 

 outer part of their wings ; and secondly, by the leaden tint of their lower 

 parts, from the neck to the tail, those parts in Sterna Hirundo being 

 pure white. The back is also of a deeper blue in the Arctic Tern. 

 The long tail-feathers were much shorter in the females than in the males, 

 but M. Temminck is wrong in saying that this bird has the tail propor- 

 tionally longer than that of other species, the Roseate Tern having it of 

 much greater length, considering its diminutive size. 



At the beginning of the first autumn, the plumage of the young so much 

 resembles that of the young of Sterna Hirundo, that a person, not paying 

 attention to the tarsi and feet, might readily confound them together. Yet 

 even at this early age, there are strong indications of the bluish tint on the 

 under parts. The longest tail-feathers at this period do not extend more 

 than two inches beyond the rest ; the upper parts of the body are mottled 

 with brown, as in all the other species, and in Gulls. The mantle of this, as 

 of all other Terns, assumes its permanent hue before any part of the wings. 

 On the 5th of August, in Labrador, the young birds were gambolling 

 along with their parents, over the shores of Bras d'Or Harbour, and when, 

 we left that country the Terns still remained, so that I am unable to 

 state at what particular period they commence their journey southward. 



The notes of this species resemble the syllables creek, creek, and are 

 often repeated while the bird is on wing. During autumn it follows 

 the sinuosities of the shores of the bays and inlets, ascending against the 

 ebb, and^ returning to meet the tide, which enables it to procure its food 

 in succession while it keeps on its course. I have only farther to mention 

 a curious fact, which is, that all the Terns which breed in the northern 

 parts of the United States, and in regions still nearer the pole, sit closely 

 on their eggs, while the small species that breed to the southward incu- 

 bate only during night, or in rainy weather. 



I; 



Stehna arctica, Temm. Man. d'Omith. part ii. p. 742. — Ch. Bonaparte, Synops. of 

 Birds of the United States, p. 354 — Swains, and Richards. Fauna Bor. Amer. 

 part ii. p. 414. 



Arctic Tern, Nuttall, Manual, vol. ii. p. 275. 



Adult Male in Spring. Plate CCL. 



Bill about the same length as the head, slender, tapering, compressed 

 nearly straight, very acute. Upper mandible with the dorsal line slight- 

 voL. in. • A a 



