GEEAT NORTHERN DIVER 503 



by diving, disappearing under the water like a flash, yet so 

 quietly that the surface where it went down is only faintly 

 marked with ripples. Its sub-marine course is very uncer- 

 tain ; I have scores of times seen it reappear fully a hundred 

 yards in the opposite direction to that in which it descended. 

 Thus a bird heading due north will dive in front of the bow 

 of a boat and perhaps come up astern swimming in a ' bee- 

 line' south. 1 The length of time during which it can remain 

 under water is remarkable. A limit of ten minutes has been 

 given by some writers ; personally I have been unable to 

 verify this statement. 



FIG. 60. GREAT NORTHERN DIVER. 



The Great Northern Diver has often been captured in 

 fishing-nets ; at other times it has been made prisoner 

 in its endeavours to escape from being stranded in the 

 shallows of bays and channels. 2 It sometimes uses its wings 

 as propelling organs under water, thereby differing from the 



1 This observation has taught me that one has, on the whole, a better 

 chance of securing a specimen if he bring his boat to a stand-still 

 directly the bird dives. A sharp look out must be kept for its reappear- 

 ance, and the shot must then be fired immediately, for if the bird rises 

 near the sportsman and sights him, it will instantly disappear. 



2 In water, insufficiently deep to swim or dive, I have seen this bird 

 stand quite erect as though puzzled at the behaviour of the fast receding 

 tide. 



