214 THE SKUAS 



ning speed, follows closely its every movement, its twists, rises, 

 descents, and by mere hustle and dash and noise seeks to gain its 

 object. Both birds fly screaming in a wild erratic course, the skua 

 sometimes breaking away, but only to resume the chase, which goes 

 on till either the pursuer has had enough, or the pursued surrenders 

 the fish. Thereupon the skua drops like an arrow and catches its 

 plunder before it reaches the water or does not. In the latter 

 case, it rarely makes any attempt to follow it further. One, however, 

 was seen not only to alight on the water, but when the fish sank, to 

 dive right under, remain under for a moment, and reappear, though 

 without the fish. 1 



Skuas succeed best when they hunt in pairs, but success 

 depends very much upon the strength and temperament of the 

 pursued. Sometimes Terns, instead of trying to escape by flight, have 

 been seen to drop their fish before the skua was near enough to 

 profit, and then, upon the latter turning to fly off, swoop down and 

 retake possession. 2 Sometimes the proposed victim escapes by 

 settling on the water and showing fight. It is enough, at times, for 

 it to alight in order to be freed from aggression. This was noted 

 in the case of a lesser blackbacked-gull chased by a great-skua. 3 

 Of the piracies of the latter species there is, comparatively speak- 

 ing, a lack of recorded detail, but they are of the same general 

 character as those of the Arctic. 



There is little evidence that Skuas catch fish for themselves. 4 

 They are no doubt quite as capable of doing so as Gulls, but find it 

 easier to exploit weaker birds. Their diet, however, is by no means 

 limited to fish. Like the Gulls, they are omnivorous. The great-skua 

 will not only rob fish from weaker species, but make a meal of the 

 birds themselves. Its castings, like those of the larger Gulls, are 



1 Annals of Scottish Natural History, 1908, 11. 



1 E. Selous, Bird Watcher in the Shetlands, p. 11. 



5 Patten, Aquatic Birds, p. 455. 



4 Naumann ( Vogel Mitteleuropas, xi. 307, 325) states that both the Arctic and great-skua 

 fish for themselves after the manner of Gulls, but it is not clear from the context that he is 

 writing from personal observation. 



