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Early in the summer they begin to collect along the shores of Lewis, Harris, North Uist, 

 Benbecula, and, indeed, the whole of the Long Island, where they linger until the beginning of 

 June, some remaining even as late as the middle of the month. A few remain in Benbecula all 

 the summer ; the nest, however, has never been found. They return some time in August, and 

 are seen in groups of fifteen or twenty birds, swimming near the shore immediately on their 

 arrival. I observed a gathering of this kind on the west side of Benbecula on the 29th of 

 August 1867, and was told by a friend residing there that he had seen them fully a fortnight 

 before. All the birds were in brilliant summer plumage, and, as a group, formed a spectacle 

 which is not often looked upon by even the most fortunate ornithologist. In many of the sounds 

 and saltwater reaches of the inner islands, similar companies have been observed at the beginning 

 of the season. Dr. Scouler has informed me that, in the course of a yachting cruise among these 

 islands, he has seen from fifty to sixty Great Northern Divers, all in groups of six or eight birds, 

 preparing to quit the coasts for their breeding-stations. Where these may be I am at a loss to 

 conjecture. The absence of the birds extends through so short an interval as to preclude the 

 idea of the journey being a lengthened one. In six weeks at most many of them are back to 

 their old haunts, even as far south as the coasts of Ayrshire, where I have seen adult birds in 

 August, accompanied by their young ones little larger than a Mallard. As the species is much 

 later in spreading along the eastern shores of Scotland, it may be presumed that the Great 

 Northern Divers of the western islands are hatched either in Iceland or on the north-eastern shores 

 of Greenland. It is possible that Greenland birds may leave sooner than those bred in Iceland, 

 as, on referring to Professor Newton's very interesting list of the birds of the latter country, it will 

 be seen that mention is made of this Diver forming into parties on the sea in the end of August, 

 and remaining off that coast during the winter. Although it has been at various times hinted 

 that the species may have bred in this country, positive proof is yet wanting to set the question 

 at rest." Dr. Saxby says: — "According to Messrs. Baikie and Heddle, the Great Northern Diver 

 is common in Orkney at all seasons in its immature state, old birds being more abundant in 

 winter ; I have not, however, heard whether the belief entertained by those gentlemen, that it 

 breeds there, has yet been confirmed. With us it arrives during the month of September in 

 considerable numbers; but a large proportion disappear about Christmas. In April and May 

 they again become plentiful ; but among the few which remain throughout the summer adults 

 are rarely seen. In the winter months a few at least are constantly to be seen in almost every 

 voe or bay ; but I have not observed more than a dozen at one time ; and that was an unusually 

 large number. The Immer frequents also the whole line of seaboard, feeding close along the 

 face of the deep rocks, and, when the surf becomes too heavy for it there, going boldly seaward, 

 or sometimes, if compelled by hunger, entering the voes. There it occasionally happens that the 

 young coalfish have gathered in immense shoals ; and in this case the Divers are in no hurry to 

 return, continuing in the voe until the fish depart, and becoming so extremely fat as to be 

 scarcely worth the trouble of preparing as specimens." Dr. Saxby believes that it occasionally 

 breeds there ; but his only reason for so doing is because he had some very large Diver's eggs 

 sent to him ; and this can scarcely be accepted as a valid reason, as eggs of Colymbus arcticus are 

 occasionally found quite as large as those of the present species, and I have taken eggs of the 

 Great Northern Diver which vary greatly in size. 



