SKUAS 255 



with great dash and agility and, with quick stoops and swerves, worries 

 and frightens the quarry until it abandons its catch in mid-air or dis- 

 gorges its last meal. Very often the skua, with a graceful aerial dive, 

 catches the fish, or whatever the prize may be, before it falls into the sea. 

 Meinertzhagen noticed that skuas in the Shetlands adopt a special 

 method of robbing gannets. They seize the tip of the gannet's wing, 

 causing it to crash into the sea and flounder helplessly in the water. 

 The skua only lets go when the gannet has disgorged. At other times 

 the skua seizes the gannet by the tail and tips it up into the water. 



The arctic skua, which is the commonest British species, is a smaller 

 bird and easily distinguished by the two long straight feathers projecting 

 from its wedge-shaped tail. These are clearly seen on Plate XXXVIIIa 

 Its upper parts are uniformly brown, but the breast varies considerably 

 and is sometimes almost white. Its habits are similar to those of the great 

 skua, although in stormy weather it is more often seen inland. The 

 arctic skua also obtains its food principally by piracy. It concentrates 

 more on the smaller gulls, such as the kittiwakes and terns, but it also 

 pursues puffins and guillemots. When the skua has selected a victim 

 it follows it with great persistence, turning and twisting with amazing 

 agility and chasing it relentlessly until the food is dropped. It then 

 catches it with a single stoop and swallows it in mid-air. Despite their 

 piratical habits the skuas are all capable of capturing their own prey. 

 Apart from fish and other marine organisms they kill and eat a wide 

 range of young birds and some adults, devour eggs and carcases and 

 various insects including beetles and dragon-flies. They also take 

 small mammals at their breeding haunts, and have even been known to 

 kill lambs. 



