44 BRITISH BIRDS WITH THEIR NESTS AND EGGS. 



as Brazil, crossing by the isthmus of Panama to the northern parts of Peru and 

 Chili. 



The Arctic Tern arrives in this country on its northern migration, about the 

 same date as the Common Tern, and is seen along all our coasts (though but rarely 

 inland) towards the close of the month of April, and at a correspondingly later 

 date at stations further north, some of which may not be reached till June or 

 July. In the Orkney Islands, Harvie-Brown and Buckley, in their Fauna of that 

 region, note that the Arctic Terns " appear to arrive with remarkable punctuality 

 between the i5th and iyth of May, there being only one record as early as May 

 6th." After their arrival they congregate on rocks or on the shore, and for a time 

 appear to have no object in life but the catching of fish and the delights of feeding. 

 Before the end of a fortnight, however, their separating off in pairs indicates that 

 they have been pursuing other pleasures. 



The sexes are alike, and in their summer or breeding plumage the adults so 

 closely resemble the Common Tern iu general colour, that it is difficult to distin- 

 guish the two species. The Arctic Tern, however, may be recognized by having 

 the bill shorter and more slender than that in 5. fluviatilis, and, in the old birds, 

 of an entirely crimson colour, without any black on the culmen or at the tip, while 

 in length it measures i-| inches as against 2 inches in the latter. The tail is also 

 longer (exceeding the closed wings) as well as more pointed; the coral-red tarsus 

 is at all ages shorter than that of the Common Tern, never exceeding the length 

 of the middle toe (without its claw) ; the under surface is greyer, and the silvery 

 grey of the back ascends higher on the neck, leaving only a narrow streak from 

 the base of the bill below and behind the eyes white ; while the dark edging along 

 the inner side of the white shaft of the primaries is narrower and less conspicuous. 

 Length 14^ inches ; wing iOj ; tail 7 to 8, with its fork 5 inches deep ; tarsus 

 '65 to '7 ; and the middle toe with its claw '85 inch. 



" In its habits," writes Mr. Seebohm, " the Arctic Tern differs very little from 

 its relative, the Common Tern. During its sojourn on our coasts it frequents 

 rocky islands and sandy islets, and portions of the mainland coast that are both 

 secluded and furnish a suitable nesting place. Like all the Terns the Arctic Tern 

 is gregarious and lives in colonies, sometimes of enormous size, at others consisting 

 only of a few pairs. On the wing it is even more graceful than the Common 

 Tern. It looks the perfection of elegance as it beats along the coast, its long 

 wings moved now slowly, now quickly, in a very Gull-like manner. Flocks of 

 these birds usually hunt for food in company, flying along in a loose straggling 

 manner. Every now and then one of them drops suddenly down into the water 

 as if shot, and rises again with a little struggling fish in its bill. Sometimes it 



