SCIENCE-GOSSIP. 



297 



England. These important immigrations set in 

 during the latter days of September, reach their 

 maximum in October, and continue at intervals 

 until November. They are chronicled with wonder- 

 ful precision and regularity in the returns from the 

 stations on the south-east coast of England. They 

 are renewed during winter on occasions of excep- 

 tionally severe cold, but the birds then pass to the 

 westward along our southern shores. 



" There are some remarkable features associated 

 with these movements : (i) They are frequently 

 observed for several or many consecutive days ; 

 (2) they often occur when there is an almost entire 

 absence of bird-migration on other parts of our 

 shores ; (3) the movements appear to be entirely 

 confined to the daytime, and are usually timed as 

 from soon after daylight to 1 p.m., sometimes 

 until 3 p.m. — this being probably due to, and 

 indicative of, the shortness of the passage ; (4) the 

 autumn migratory flocks are chiefly composed of 

 larks in vast numbers ; ' black crows ' (rooks), 

 very many ; grey crows, many ; also numerous 

 redbreasts, goldcrests, chaffinches, greenfinches, 

 tree-sparrows, swallows, starlings, and occasion- 

 ally woodcocks ; and, during the winter, larks, 

 various thrushes and lapwings ; (5) and lastly, 

 on certain occasions these immigrants, while pass- 

 ing northward along the English eastern seaboard, 

 actually cross the movements of 'coasting' 

 emigrants proceeding southwards, (i) 



" Whether this east to west stream is a branch 

 of one that passes down the coast of Continental 

 Europe, or whether it has its source in Central 

 Europe, is a matter of conjecture, i^) 



" Intermigration between Heligoland and Britain. — 

 Much prominence has been given in some of the 

 Annual Reports issued by the Committee, and in 

 Herr Gatke's book, 'Die Vogelwarte Helgoland,' 

 to an intermigration between Heligoland and the 

 east coast of England by a direct east-to-west 

 autumn and, it is to be presumed, west-to-east 

 spring movement. Herr Gatke most obligingly 

 communicated the details of the bird-movements 

 observed on Heligoland for four of the years 

 (1883-86) during which the inquiry was being 

 prosecuted over the British area. These two sets 

 of data have been carefully examined and com- 

 compared, and it has been found that the dates of 

 the chief movements of the species common to 

 Heligoland and Eastern Britain seldom if ever 

 correspond, and do not bear out this theory ; that 

 particular species which are irregular as migrants 

 in Britain, such as the ortolan bunting and 

 others, occur regularly, often indeed in ' rushes ' 

 at the more favoured isle off the mouth of the Elbe ; 

 that other species which are very rare on our 

 British Isles occur in Heligoland as regular 

 migrants and in considerable numbers, as Motacilla 

 flava, Anthus ricliardi, etc. ; while species common 

 to both islands occur in ' flights like clouds,' in 

 ' hundreds of thousands,' ' thousands upon 

 thousands,' in 'marvellous numbers,' 'astonishing 

 flights,' and so on, at Heligoland, at periods when 

 there is not a single observation for the same 



"(') It is probable that such species as the golden oriole, 

 hoopoe, etc., which occur annually during spring and autumn 

 migration in southern and south-eastern England, and the 

 black redstart as a winter visitor, are birds that proceed 

 along this route to and from our islands." 



"(^) There are no essentially northern species recorded for 

 tliis route, and the occurrence of the rook so frequently and 

 in such numbers is suggestive of a Central (western) 

 European source." 



species on the English shores. A study of the 

 phenomena of mij:^ration at the stations on the east 

 and west sides of the North Sea compels the 

 investigator to come to the conclusion that 

 Heligoland and Britain draw their migratory hosts 

 from different sources. . . . 



" Intermigration between Britain and Faroes, Iceland 

 and Greenland. — The Faroes, Iceland and Green- 

 land, are the summer home of several Pala^arctic 

 species which occur as birds of passage on the 

 British coasts. The majority of these visit Iceland, 

 and Greenland claims only two or three of them 

 (wheatear, white wagtail and whimbrel). It is 

 natural that these birds being of strictly Old 

 World species, our islands should lie in the course 

 of their migrations. It is quite possible that these 

 migrants may pass along both the eastern and 

 western coasts of Britain and the coasts of Ireland. 

 Here, at any rate, we have evidence that these 

 birds are observed on passage on our western 

 shores. It may be that some of the birds proceed 

 also along our eastern seaboard, but this is a point 

 difficult to determine. There is good evidence, 

 however, that important movements of redwings, 

 wheatears and whimbrels are observed on the 

 western coast of Great Britain and the Irish 

 coasts (both east and west as regards the passage 

 of the whimbrel) which are not observed else- 

 where. Such a fact points to the independent 

 nature of these west-coast flights, and indicates 

 that, in some instances at least, the western route 

 alone is followed. 



" It is thus evident that, so far as concerns the 

 movements of the birds of passage to and from 

 their northern breeding haunts, the British east and 

 west coast migratory movements are very distinct 

 in their characters. The west coast does not receive 

 immigrants direct from Europe, nor do these 

 Continental breeding species depart from its shores 

 in the spring. Indeed, it is quite remarkable how 

 rare, or comparatively rare, certain well-known 

 east-coast species are on the western points of our 

 shores. 



" Intermigration between Great Britain and Ireland 

 and the South, etc. — Having shortly described the 

 migratory movements between the British Islands 

 and Northern and Western Europe, undertaken by 

 birds of passage and winter visitors to our Islands, 

 the routes on our coasts along which the summer 

 visitors travel to and from their breeding quarters 

 in Great Britain and Ireland now demand attention 

 in their geographical aspect. It will be convenient 

 also to refer to the routes between the different 

 portions of the British area under this division. 



" The autumn or emigratory movements will be 

 described — but it is necessary to remark that the 

 data clearly indicate that the spring migratory 

 movements along our western shores are simply 

 return movements on the part of the same species 

 along the same lines of flight as those laid down 

 for the autumn. 



" The movements of these groups of migrants 

 will be treated of under the various sections of our 

 coasts. The first movement on the part of all 

 emigrants among British birds is to the coast, 

 which is reached in some cases, no doubt, by 

 particular inland routes. 



"East Coast of Great Britain. — The emigratory 

 movements on the east coast are very simple in 

 their geographical aspect. When the coast is 

 reached, the emigrants follow the coastline south- 

 ward, gathering strength as they go, and finally 

 quit our shores at various points on the south 

 coast of England. 



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