GULLS— SKUAS. 



263 



allies, another British species being the little gull (i. minntui). The other 

 gulls with which we are familiar in this country, such as the greater black- 

 backed gull {L. marhms), the lesser black-backed gull (L. fuscns), the her- 

 ring gull (L. argentatus), liave white heads and white tails. The habits of 

 gulls are much the same all the world over. They feed mostly on fish ; but 

 some of the larger kinds are not only 

 great robbers, but will eat almost 

 anything, and will devour young birds 

 and even sickly mammals. The little 

 black-headed gull, on the other hand, 

 is a most useful bird, as it frequents 

 and breeds in inland districts, where it 

 often follows the plough, and devours 

 large numbers of grubs and insects. 

 The other gulls breed on the rocky 

 coasts, mostly in the north, sometimes 

 in vast numbers together. This is 

 especially the case with tlie kittiwake 

 {Bissa tridactyla), which is separated 

 from the true gulls on account of the absence of a hind toe. 



The skuas are often called the parasitic gulls, from their habit of robbing 

 the smaller gulls of their food, instead of catching it for tbemselves. They 

 differ from the true gulls in having a cere, or bare wax-like 

 base, to the bill. The latter is very strongly hooked at the 

 tip, and in the posterior portion of the sternum, or breast- 

 bone, tliere is only a single notch, instead of two, as in the 

 gulls. 



Four species of the great skuas are known, of which one, M. catarrhactes, 

 is an inhabitant of the North Atlantic, where it breeds in a few scattered 



localities, such 



as Iceland, the The Great Skuas. 

 Faeroes, and — Genus 



Norway, and a MegaXestris. 

 few pairs still 



nest in the Shetland Isles, where 

 great pains are now taken to 

 preserve them, as they had be- 

 come nearly extinct there. They 

 not only feed on fish and car- 

 rion, but rob other gulls of 

 their prey, and even kill and 

 eat some of the smaller species. 

 The eggs are two in number, 

 and the birds becomo very bold 

 in defence of their nests. A 

 second species of great skua 

 {M. chilciisis) inhabits both the 

 Atlantic and Pacific coast-s of 

 South America, from Peru on the west, to Southern Brazil on the east. 

 From the New Zealand seas to Kerguelen, and thence to the Falkland Islands, 

 occurs M. antarctica, while in Victoria Land and the frozen countries of the 

 Antarctic Continent is found a peculiar pale form of great skua, M. mac- 



Fig. 27. — The Common Gull 

 (Larus canuts). 



The Skuas. — 

 Family 



Stercorariidce. 



Fig. 23.— Buffon's Sk.ua (Sfcrcorarius varasificiiif) 



