158 BIRDS OF THE BRITISH EMPIRE. 



L. canus. Common Gull. 



L. vian'nus. Greater Black- 

 backed Gull. 



L. ridibundus. Black-headed 

 Gull. 



4. Sterna. S. hiruudo. Common Tern. 



5. macnira. Arctic Tern. 



5. HydrocJielidofi. H. nigra. Black Tern. 



Skua. — This is one of the largest members of the family, 

 measuring 2 feet 2 inches in length. The female is smaller, 

 but otherwise resembles her mate, who may be described as 

 brown, darker above than below : the feathers of the neck 

 are long and pointeil, and can be raised by the bird at w'ill. 

 The long narrow wings measure, when extended, nearly 5 

 feet from tip to tip, so that the skua is extremely powerful 

 on the wing, and is much feared by other bird.s. It still 

 breeds in a few places in Scotland, but is in great danger of 

 extermination, for during the breeding season it exhibits 

 great fierceness, sparing neither man, beast, or bird that 

 approaches the spot where its large nest is placed in the 

 vicinity of the sea. The two eggs are dark, and the young 

 are at tiist covered with dark blackish down ; there is a 

 white patch on the wing ; the bill is very strong and 

 hooked. It Hies strongly and for a long time without 

 resting. It attacks other gulls to deprive them of their 

 prey ; sometimes they are called " parasitic gulls, because 

 they subsist on the labours of others." 



KiTTiWAKE. — A very elegant species, white, with a faint 

 bluish tinge on the head, neck, breast, and under parts ; 

 pale slate blue on the back and wings ; flights black, 

 several of the secondaries have white tips ; bill dull orange, 

 shaded with grey ; legs dark greenish black ; hind toe 

 rudimentary. The eggs are two or three, and differ mucl^i 



