22 BRITAIN'S BIRDS AND THEIR NESTS. 



This is the habit of swimming or resting in the water in a 

 submerged or half-submerged position. A Dabchick on the 

 approach of danger can gradually sink lower and lower 

 in the water till its back is awash, then till only head 

 and neck remain above the surface, and finally till only 

 the beak protrudes. Usually the bird dives and swims 

 under water to a safer place before this last stage is 

 reached. But in a small pond a Dabchick has been 

 observed trying to escape detection by remaining in one 

 place, with only the beak appearing, and this looked so 

 like one of the small floating objects that abounded 

 there that the presence of the bird would not have been 

 noticed by any one who had not seen it sink. Now, a 

 Dabchick, or any bird for that matter, must weigh less 

 than a quarter of the weight of its bulk of water, and 

 will therefore, alive or dead, float buoyantly on the 

 surface unless some considerable force be exerted on it. 

 In the ordinary diving, which must not for a moment 

 be confused with this submerging, the bird itself obviously 

 exerts this force. But in the submerging we do not yet 

 know what means are employed. Close observation of 

 Dabchicks and others in captivity has failed to detect 

 any motion, where violent motion appears to be a si7ie 

 qua non. The habit is shared by Divers, Grebes, 

 Ducks, Cormorants, and probably others, and an apparently 

 similar phenomenon is the Dipper'^s walking on the bottom 

 of a stream. 



Of the Little Grebe's other powers in the water we 

 need add nothing further, but they are familiar to most 

 dwellers in the coimtry, and may even be studied on 

 many of the ornamental waters in London parks. The 

 name ' Dabchick ' is equivalent to ' Dipchick,"* and is of 

 course a reference to the bird's powers of diving and 

 of submerging itself. 



