( 142 ) 

 NOTES ON THE GREAT NORTHERN DIVER. 



BY 



ERIC B. DUXLOP. 



The Great Xorthem Diver [Gavia immer) is best kiiOA\n 

 in the British Isles as a winter-visitor, though in the 

 Orkneys I have frequently seen it in summer, and it does 

 not appear impossible that it maj' occasionally have 

 bred there on some remote loch. 



In Canada I was able to make observations on two 

 breeding pairs, one having eggs, the other 3'oung, and also 

 with the help of a blmd to photograph the bird on her eggs. 

 The nest with the eggs was composed of a mass of grasses, 

 sedges and moss, heaped together on a submerged bank, 

 which was about three inches beneath the surface of the 

 water. It was at the margin of a small lake. This nest 

 had undoubtedly been made by the birds themselves ; 

 the material would have filled a large washing-basin 

 to overflowing. The bird \\-as seen to pick up a piece of 

 vegetation whilst incubating. 



Whenever the bird was put off the nest she dived from 

 it into the water with a splash, coming up some distance 

 away and frequently s\\imming with the body submerged 

 and only the head showmg. On a close approach being 

 made to the nest, both birds became bolder and occasion- 

 ally came within about thirty yards, swimming on the 

 surface. 



After erecting the blind, it was left overnight, and the 

 attempt to photograph the bird was made the followuig 

 day. After waiting a consideral^le time the bird swam 

 up to the nest and shuffled on to it. She then moved 

 the eggs with the open beak, holding them between the 

 mandibles whilst arranging them. Next she partially 

 settled down on them, tlien got up and moved the eggs 

 with the open beak agam, and then finally settled do^n. 

 One of the jjhotographs shoe's the position assumed by 

 the bird when arranging the eggs. I saw her come on to 

 the ne.st on three occasions. Each time she swam and 

 dived about until A\itliin thirtv vards. She then dived 



