_Rhynchops_ has a peculiarly low flight, rapid and gliding, with many a turn and twist, which has gained it the name of Skimmer. The food, often sought towards evening, appears to consist of small fish and crustaceans; it is procured by keeping the bill wide open, with the long mandible ploughing through the water or mud, and leaving a distinct furrow in its track. The cry is a low harsh scream or shrill twittering note. A hollow in some sandy river-bank or island serves to contain the three or four grey, green, buff, or white eggs, with blotches and streaks of purplish-grey and dark brown. The female is said to sit only at night or in stormy weather, and the young to be unable to fly for several weeks,[198] but the remaining habits resemble those of Terns. The sexes in the Laridae are invariably similar, the plumage being grey and white, or more rarely blackish or brown, details of which will be found below. The young are duller, being mottled with brown or black in immature Gulls. The frequent black or brown heads, often lacking at certain ages or times of year, the seasonal changes generally, the neck-collar of _Xema sabinii_ and _Rhodostethia_, and the rosy tint on the breast in the latter species, _Larus franklini_, and _Sterna dougalli_ may be noticed in passing. The members of the Family range in size from the Glaucous to the Little Gull; the largest Tern being the Caspian, and the smallest, as its name indicates, the Least Tern. Sub-fam. 1. _Stercorariinae._–Of this widely spread but curiously distributed group, _Megalestris catarrhactes_, the Great Skua or Bonxie, a fine rufous-brown species, with a white wing-patch which is very conspicuous in flight, breeds in Shetland, the Färoes, Iceland, and possibly north of Hudson Strait, occurring in South Greenland and Norway, and reaching New England and Gibraltar in winter. It nests in colonies, though each pair occupies a distinct area, which the parents defend with exceptional boldness, swooping down swiftly with a heavy rush, and dropping the feet when at close quarters, as if to strike an intruder. Unlike their smaller kin, which will attack a man from any side and hit him with their wings, these birds commonly aim directly at the face, and their onslaught, if not averted, is really dangerous, while they only just clear the head when threatened with a stick. The two eggs, deposited in a depression {305}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. chilensis_, spotted with chestnut above, and more rufous below, occupies America south of Rio de Janeiro and Callao; the sooty-brown _M. antarctica_–the stouter-billed Port Egmont or Sea Hen–replacing it from the Falklands to the Australian and New Zealand seas, and reaching northwards to the Comoros and Madagascar.