302 CHARADRIIFORMES chap. 



Bonaparte's Gull. All walk well, though sedately, swim to per- 

 fection, and rise easily both from land and water, usually break- 

 ing into a run before taking to the wing from the ground ; while 

 they almost invariably alight with uplifted pinions. The wild 

 characteristic note varies less than in most large groups, that of 

 the bigger species being harsh and querulous, that of the smaller 

 " laughing " or screaming ; the lesser Skuas give vent to a 

 curious mewing cry, and the Great Skuas to a similar but deeper 

 sound. At the breeding-quarters the utterances are natm^ally 

 more agitated and shrill, and the parents hang excitedly above 

 a visitor's head. The food consists mainly of fish, molluscs, 

 crustaceans, and worms, but is varied in the stronger forms by 

 small mammals, young birds, and eggs : the Great Black-backed 

 Gull undoubtedly attacks lambs and weakly ewes ; carrion is 

 not uncommonly devoured ; and Lams maculipennis acts as a 

 scavenger at Buenos Aires, besides clearing the coimtry of grass- 

 hoppers, and robbing the Cayenne Lapwing of its insect booty. 

 Skuas give chase to their smaller kin, and force them to disgorge 

 the fishes they have just caught, while even Solan Geese are 

 sometimes victimized ; Larus scopulimis, moreover, which robs the 

 Oyster-catcher of New Zealand, is a further instance of parasitic 

 habits. Insects and their larvae, turnips, berries, and grain are 

 also eaten by these omnivorous but useful creatures. Their main 

 sustenance is naturally derived from the ocean, or its oozy shores ; 

 but flocks are commonly seen on pastures and arable lands near 

 the beach, or following the plough further from the sea, though 

 not being of the species which breed in the interior, nor 

 driven inland by stress of weather. At times Gulls almost, if 

 not quite, disappear below the water when swooping on their 

 prey, and Kittiwakes have been said to pursue it beneath the 

 surface. A common habit is that of preening and washing the 

 plumage in company at favoured spots, while one that is less well- 

 known is that of casting up the indigestible parts of the food in 

 pellets, as do many other birds. The nesting sites are very 

 frequently precipitous rocks and stony islands, but inland 

 marshes and lakes accommodate many species, while in certain 

 localities trees as high as thirty feet are selected. Skuas breed 

 on moors or hills near the sea in Scotland, on the fells of Scandi- 

 navia, and on the tundras and barren grounds of the Arctic Eegions, 

 the nest being a mere depression in the herbage or moss ; the 



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