V LARIDAE 305 



sion in the herbage, are dull brown or greenish, with somewhat 

 indistinct umber markings. The food consists chiefly of fish, 

 which the smaller Gulls are forced to disgorge, while Kittiwakes and 

 the like are themselves occasionally devoured in default of other prey. 

 M. chilcnsis, spotted witli chestnut above, and more rufous below, 

 occupies America sou.th of Eio de Janeiro and Callao ; the sooty- 

 brown Jf. antarctica — the stouter-billed Port Egmontor Sea Hen — 

 replacing it from the Falklands to the Australian and New Zealand 

 seas, and reaching northwards to the Comoros and Madagascar. In 

 the Antarctic Victoria Land occurs a paler form, M. riiaccormicki. 



Stcrcorarius pomatorhiims, the Pomatorhine Skua, breeds on 

 the tundras of Siberia and possibly from Greenland to Bering Sea, 

 migrating to Britain and as far as South Africa, North Australia, 

 and Peru. Tlie plumage is brown, with blacker head and gorget, 

 white breast, and acuminate white neck-feathers tipped with yellow. 

 The projecting median rectrices with their vertically twisted vanes 

 are mentioned above (p. 301). Uniform brown specimens may be 

 immature. K crepidatus, the Arctic Skua, is smaller, and nests as 

 far south as Northern and Western Scotland, but properly occupies 

 Arctic and sub- Arctic Europe, Asia, and America ; in winter, 

 it reaches South Africa, Australia, New Zealand, and Brazil. The 

 elongated rectrices are not twisted, but are pointed, while a uni- 

 form dark phase — the true >S'. richardsoni — is common to both sexes. 

 S.'jparasiticus, Buffon's Skua, distinguished from the last-named by 

 its extremely prolonged rectrices and greyer upper surface, breeds on 

 the Scandinavian fells and throughout the Arctic tundras and barren 

 grounds, migrating as far south as Gibraltar and lat. 40^ N. in 

 America. The habits of the members of this genus are similar 

 to those of Mcgalestris, but their quicker flight enables them to 

 rob even Terns, and the mewing cry is most peculiar, while the 

 eggs are intermediate in style between those of Whimbrels and 

 Gulls. These small Skuas often destroy Lemmings. 



Sub-fam. 2. Larinae. — Rissa tridactyla, the Kittiwake, breeds 

 from the circumpolar regions southwards to the Kuril Islands, the 

 Gulf of St. Lawrence, and North-West France ; in winter it reaches 

 western North America, the Bermudas, the Canaries, the Mediter- 

 ranean, and the Caspian. The feet are black, the hind-toe is 

 absent or rudimentary. From Larus canus, which it closely 

 resembles when flying, it can be distinguished by the absence of 

 white spots at the ends of the primaries. The young bird, or 



VOL. IX X 



