RED-THROATED DIVER. 413 



the Pacific coast as far south as California, occasionally on the Great Lakes, 

 and on the Atlantic coast as far south as the mouth of the Potomac. 



The habits of the Red-throated Diver are so similar to those of its allies, 

 that little need be said respecting them. It is perhaps the most gregarious 

 of the Divers, being frequently found in small parties during winter ; but 

 in the breeding-season each pair has its own district, which it jealously 

 guards from the intrusive visits of any other members of the species or 

 even genus. A remarkable exception is to be found on the island of 

 Tamso, in the Porsanger fjord, beyond the North Cape in Norway. On 

 the banks of a tarn in this island Collett found fifteen nests of the Red- 

 throated Diver in half an hour. The probable explanation of this curious 

 deviation from its ordinary habits is to be found in the fact that the tarn 

 contained no fish. The island is strictly preserved as an Eider-Duck 

 nursery, and the lessee pays an annual rent of three hundred pounds of 

 Eider down. The Divers have discovered that it is a safe breeding-place, 

 and use it as such only, feeding in the fjord, where possibly each pair may 

 have their own special range. As no food is to be obtained in the tarn, 

 which also is the great resort of Gulls, Grey-lag Geese, and Eider Ducks, 

 there is no reason why the Divers should be jealous of each other. 



Where the other Divers are found the times of migration and nidifi cation 

 of the Red-throated Diver are the same as theirs. In Iceland fresh eggs 

 may be obtained from the end of May to the middle of June ; but in the 

 Taimur peninsula Middendorff did not find eggs until early in July. 

 Collett found two eggs in each of the fifteen nests he found on Tamso, but 

 on the 3rd of July most of thera were considerably incubated. 



The Red-throated Diver very rarely makes a nest ; the eggs are often 

 laid on the bare turf, often in a depression on the grass or moss, but a 

 scanty lining of weeds or sedge is frequently found. The eggs are somewhat 

 more variable in colour than those of its allies, being more commonly of 

 a brownish olive than of a russet-brown ground-colour; the spotting is 

 also occasionally somewhat bolder. They vary in length from 3'1 to 25 

 inch, and in breadth from 1*9 to 17 inch. Large eggs of this species 

 cannot be distinguished from small eggs of the Black-throated Diver. 



In almost all respects the Red-throated Diver resembles its allies. Its 

 ordinary call-note is an ak, ak, but at its breeding-grounds the same wild 

 screams are heard as those produced by its congeners. Its food, mode of 

 flight, shuffling walk, and marvellous skill in diving closely resemble those of 

 the other Divers. Gatke observed the Red-throated Diver in exceptionally 

 large numbers, " almost by the million,^' at the end of the year 1879 

 near Heligoland ; they were migrating towards the north-east for several 

 days. 



Respecting the power which this and some other birds have of sinking 

 in the water, my friend Mr. Lloyd Patterson writes to me as follows : — 



