90 THE TERNS 



in digesting their fish whole. A chick may not infrequently be found 

 with the tail of a fish longer than itself projecting from the end of 

 its beak. The tail gradually disappears inside as the head portion 

 becomes assimilated. The fish is either given directly to the young, 

 or is dropped in front of it, sometimes from the air. Insects and worms 

 are also brought, especially when stormy weather makes fishing diffi- 

 cult. On a wet evening, at Sule Skerry, Orkney, Arctic-terns have 

 been seen in hundreds all over the island, hovering about six feet 

 above the ground, every now and again darting down to the ground, 

 seizing a worm, carrying it off to the chicks, scarcely alighting to put 

 it into the wide-open bills, and then flying off for more. 1 When the 

 young are on the wing, they still continue to be fed, receiving the food 

 in the air, or else waiting for it on the shore. 



The Tern's method of fishing is to hover, with rapidly vibrating 

 wings and with beak usually down bent, some twenty feet over the 

 surface of the water, where it looks much like a large white butterfly 

 suspended on the end of invisible string ; thence, when it has located 

 its prey, it drops head-first, its wings half closed, and enters the water 

 with a splash, emerging almost immediately with or without its fish. 

 The extent to which the common and Arctic-terns submerge them- 

 selves depends no doubt upon the height from which they descend. 

 Personally I have never seen either species disappear completely. 

 But that the Arctic-terns do so occasionally was the opinion of Saxby, 

 who wrote that in deep water "they would bury themselves com- 

 pletely out of sight." 2 Both species also take food off the surface 

 after the manner of Gulls, that is, without alighting or wetting their 

 plumage ; they pause just above the water, pick up the object with 

 the tip of the bill, and are off again at once. 



Their usual method of picking worms and insects from the 

 ground appears to be simply a modification of that adopted in fishing. 

 They hover, alight for an instant, and are up again. They have been 



Annals of Scottish Natural History, 1904, 23 (J. Tomison). 

 2 Birds of Shetland, p. 326. 



