GREAT NORTHERN DIVER. 403 



be found breeding in some secluded corner of the " sister isle." As is 

 usual, the greater number of birds that visit us are in immature 

 plumage. 



The Great Northern Diver appears to be a Nearctic species, breeding 

 across the American continent from Greenland to Alaska, as far south as 

 the Great Lakes. To the east it breeds in great abundance on Iceland, 

 but it only occurs in the Faroes on migration. To the shores of 

 Scandinavia it is principally known as a winter visitor. There is no 

 evidence of its ever having bred on the continent of Europe, unless the 

 occurrence of a fully-fledged bird on an island near Tromso, on the 26th 

 of August, may be accepted as such. It winters as far south as the Pacific 

 and Atlantic coasts of Northern Mexico. To Southern Europe it is only 

 known as an accidental visitor in winter, most of the examples obtained 

 being in immature plumage. 



Few birds are more completely aquatic in their habits than the Great 

 Northern Diver : for three or four months during the breeding-season it 

 frequents some inland lake, and spends the rest of the year on the ocean. 

 It is rarely seen on land ; its legs are placed very far back, so as to enable 

 it to swim and dive with greater ease, and incapacitate it for walking with- 

 out resting its breast on the ground. It is almost as rarely seen on the 

 wing, except at the two periods of migration, but it can fly with great 

 speed. The wings, which are also placed far back, are moved with great 

 rapidity, the neck is outstretched, and the feet spread out to assist 

 the tail by acting as a rudder. The flight is straight like that of 

 a Duck. Although small flocks are occasionally seen on migration, it is 

 not a gregarious bird, only on very large lakes are more than one pair to 

 be met with in the breeding-season, and in winter seldom more than one 

 or two birds are seen together. Like most large birds it is very shy, and 

 if pursued generally seeks safety by diving. Holboll states that it has 

 been observed to remain as long as eight minutes under water. It chooses 

 the most secluded lakes for its breed ing- quarters, and frequently selects a 

 mountain tarn for this purpose, though never at any very great distance 

 from the ocean. It arrives as soon as the ice disappears, late in May or 

 early in June. The birds arrive ready paired, and no time is lost in 

 selecting a site for the nest. An island is preferred ; but if the lake does 

 not contain one, the nest is built on the shore, near the water's edge, in the 

 most exposed situation possible. This bird makes no attempt to conceal 

 itself on the nest, but trusts to its keen eye and commanding position to 

 see its enemy before it is itself seen, when it takes to the water, relying 

 upon the protective colour of its eggs for their safety. Its mate is also 

 always on the watch to give the alarm. The nest is very clumsily made 

 and often very slight ; it is composed of dead grass and decayed water- 

 plants, and the sitting bird soon treads a pathway down to the water's ed-e. 



