33 British Birds, with their Nests and Eggs. 



In the western hemisphere it only breeds south of the Arctic circle, whence 

 as far south as Florida it is found on the coast and the inland lakes during 

 summer ; migrating, in winter, to the coasts of Brazil ; but it is unknown on the 

 western side of those continents. 



The Common Tern begins to arrive in Britain in small flocks, mostly of old 

 birds, early in May, often during the prevalence of east wind. 



According to Mr. Booth, iu spring and autumn, "while on their way to and 

 from their breeding quarters, these Terns may be observed, in considerable numbers, 

 off various parts of our coast line, the first comers usually put in an appearance 

 towards the end of April, and all through May a stream of birds in larger or 

 smaller parties continues, at short intervals, to pass onward towards the north. 

 The most general movement appears to take place about the middle of May, when 

 numerous flocks are occasionally met with in the Channel, heading steadily towards 

 the east ; after reaching the open sea their course is turned further north, some 

 making for their breeding places on the shores of the firths and lochs of the 

 Highlands, while the remainder continue their journey to more distant lands across 

 the ocean." 



The authors of " A Fauna of the Outer Hebrides " remark that however 

 punctually Terns may make their first appearance, the actual time of their occupying 

 the nesting sites "varies greatly with the weather, as also to some extent in 

 different localities, especially, as we have noticed, in the Hebrides and western 

 districts of Scotland. 



" It is not until some time after the first appearance of the Terns that the 

 ova of many species of fish hatch out, nor do the fry at once approach shorewards 

 and surfacewards. Many are hatched out on shoals and sand-banks, or even in 

 deep water at a distance from land ; and, in a late season especially, Terns and 

 other birds have to feed at a longer distance from their haunts on this account. 

 .... The time of the laying of the Terns is coincident with the time of their 

 food supplies being most accessible to them. The natural history of birds and 

 fishes in similar respects is therefore closely connected with each other's existence." 



After their arrival these Terns spend a week or so in inspecting their 

 whereabouts. They are, of course, very nearly, if not quite, in their full summer 

 plumage ; and having mated they finally fix upon a breeding place. The male is 

 indistinguishable from his partner. Both sexes have the forehead from the level of 

 the nostril through the centre of the eye, from above the ear-coverts over the crown 

 to the nape, black ; the chin, cheeks, sides of the head (including the lower part 

 of the eye and the ear-coverts), rump and upper tail-coverts, under tail-coverts, 

 under wing-coverts and axillaries, white ; the rest of the under side vinous-grey ; 



