COMMON TERN. 551 



grey, which assumes a darker and more vinous tint on the 

 breast and abdomen ; the mantle and wings are also much 

 darker, and the bill and feet smaller than in average 

 examples of the Common Tern. From Lake Baikal to 

 Kamtschatka and Japan, this form is replaced, in its turn, 

 by a very distinct species, S. longipennis, which resembles 

 the Arctic Tern in its slender form and grey-tinted under 

 parts, but differs from both species in having the legs 

 and feet brown, and the bill black in the breeding-season, 

 and probably at all other times. It appears to be the 

 Asian form, S. tibetana, which visits Ceylon, and also the 

 southern coasts of Africa, in winter, but . fluviatilis can 

 positively be traced along the west coast as far as Accra. In 

 the Ked Sea and down to the Laccadives, the representative 

 species is S. albigena, a slender Tern of a general smoky 

 hue, the rump and tail being as dark as the mantle. 



The Common Tern nests in May and June, depositing its 

 eggs, usually three in number, on the sand, shingle, or 

 dried wrack in the vicinity of water ; often in sheltered situa- 

 tions amongst sand-hills. The nest is a mere depression, 

 occasionally with the addition of a few crossed bents. The 

 eggs are of a slate-grey or yellowish stone-colour, blotched 

 and spotted with ash-grey, and dark red-brown ; average 

 measurements 1*7 by 1*1 in. On fine warm days, the 

 parent birds are seldom to be found sitting on their eggs, 

 but they cover them at night and during inclement weather. 

 On the approach of an intruder, they show many signs of 

 anger and distress, uttering a sharp pirre ; and if the young 

 are hatched, they will often contrive to feed them, unper- 

 ceived, by skimming over the spot, and dropping small fish 

 close to the nestlings, whose mottled colour renders them 

 almost undistinguishable from the surrounding shingle. 

 They never dive, but they may often be seen floating on the 

 surface of the water. 



The food of the Common Tern, like that of its congeners, 

 consists of young coal-fish, sand-eels and such small fry, 

 shrimps, and crustaceans, and they will frequently catch 

 fish when thrown to them by the fishermen, before they 



