1/2 GILL GROUP 



summer being of the normal black, while the upper-parts in general 

 are dark pearly grey, becoming paler on the hind region of the back. 

 In winter the forehead and crown are streaked with white and the 

 under surface of the bod>' assumes a paler tint. In their first plumage 

 the young birds are mottled above with buff and show a dark band on 

 the lesser wing-coverts, while the crown and nape are streaked with 

 blackish brown. The buff down of the nestling is marked with black 

 stripes on the back, and elsewhere with black spots above, although 

 devoid of such markings below. 



The range of the common tern is very extensive, including, in 

 suitable localities, practically the whole of the temperate regions of 

 the northern hemisphere in summer ; and in winter comprising the 

 greater part of Africa, together with India, Ceylon, and the Malay 

 Peninsula, although the birds visiting the last three countries are 

 comparatively few, and, at least in the south, for the most part im- 

 mature. In Kashmir and other parts of Central Asia the species is, 

 however, abundant. Throughout the greater part of the British Islands 

 the common tern is the most numerous representative of its kind, 

 although in the north of Scotland it tends to become scarce and to 

 give place to its Arctic cousin, while in the more northern islands it 

 appears to be practically, if not completely, unrepresented. Towards 

 the north of its British range it seems to prefer estuaries or lakes to 

 the sea-coast ; and in Ireland is also found breeding on inland waters 

 as well as on the islets around the coast. 



As already mentioned, the common tern maj' be found alike on 

 rivers, lakes, and the sea-coast, and is essentially a fish-eating species, 

 which breeds in May or June according to locality. Sandy or shingly 

 beaches are its favourite nesting-sites, the three eggs being frequently 

 deposited only just above high-water mark. A well-known " tcrnery " 

 exists near Wells, in Norfolk, situated on a low-l)-ing tract of consider- 

 able size shut off from the open sea by a range of low sand-dunes. 

 Here, according to a recent account,' both the common and the little 

 tern breed in company, placing their nests in some parts quite close 

 together. Very noticeable is the marvellous correspondence in colour 

 of the eggs to their surroundings ; those deposited among rufous-tinted 

 shingle being described as showing a russet colour, while in those laid 

 among blue-grey patches of pebbles the predominating tints were 

 greyish. On the greener portion of the area, on the other hand, a 

 more or less marked greenish tint was noticeable in the ground-colour 

 of the eggs. If these observations are trustworthy, the variability in 



' .\. li. l'aUer?.on, Zoo/oi^ist, ser. 4. vol iv. p. 25S (1905). 



