ON THE MIGKATION OF BIRDS. 285 



ill a very broad fan all along our east coast, and extending from Forfar- 

 shire to the south of England, having previously crossed Heligoland on 

 September 22nd, and the tvro following days. From tiiis date, Ospreys, 

 Rough-legged Buzzards, and others of the Raptors swarmed at many 

 localities up to the end of October. 



Hooded crows came with their usual regularity, almost to a day, the 

 great flight crossing Heligoland on the afternoon of October 17th, and also 

 on the 18th ; there was a corresponding arrival along the entire length 

 of the east coast of England on the night of the 17tl), or early morning 

 of the 18th, also on the 19th. 



The season of 1881-82 will long be remembered by east coast orni- 

 thologists for the number of rare visitants which have appeared from 

 time to time, driven to westward of their ordinary lines by the prevailing 

 winds from N. and N.E. to S. and S.E. generally strong, and increasing 

 to a severe gale. The fact of ten Ospreys having been seen or procured, 

 has already been noticed ; there were two occurrences of Tengmalms Owl, 

 the Rustic Bunting at Spurn, Lapp Bunting at Tetney on the Lincolnshire 

 coast. White-spotted Bluethroats at Isle of May, and at Cley in Norfolk, 

 Glossy Ibis, five occurrences, Sabine's Gull, two on Norfolk coast, Kentish 

 Plover, Lincolnshire, Blue- winged Teal, Teesmouth, and many others. 



Again, the occurrence on the east coast of such species as the Fork- 

 tailed Petrel, is explained by the local prevalence of westerly and northerly 

 winds in Scotland, carrying them overland from the west coast, and then 

 probably getting into the tracks of the easterly and northerly winds 

 which prevailed more to the southward. Records of the Fork-tailed 

 Petrel occur at Isle of May and several localities in England, as on the 

 Norfolk coast. 



On the west coast the fullest numerical returns arc from stations for 

 the most part south of the Firth of Clyde. A rush of migrants in Sep- 

 tember, noticeable especially on the Isle of May, was observable also at 

 stations on the west coast sonth of the Firth of Clyde, and would thus 

 appear to be a general movement. 



The occurrence of the white-spotted form of the Blue-thi-oated 

 Warbler,' after a succession of tremendous gales, culminating in the 

 dreadful hurricane of October 14th, seems to show clearly that the acts of 

 voluntary migration do not take place Ju following winds. This Bine- 

 throat was caught up and borne away tiolens volens, and our Mid-Atlantic 

 Notes in 1880 show similar abnormal results from the prevalence of 

 easterly gales. 



The form of the migratory movement is affected by the prevailing 

 winds even more than the severity or otherwise of the weather. 



The subject of heights of lanterns and their colours has not developed 

 as yet any fresh facts, but with the conviction that they will yet do so 

 the table of heights is retained. Actual experiment might set this part of 

 the subject at rest (vide General Remarks E.G. Scotland, Report 1880 

 pp. 19,20). 



A light- vessel or two placed in an equally favourable position with 



let ns say — the Isle of May or the Bell Rock on the east coast, or at some 

 point north of Tweed, would, I believe, soon show us whether the pre- 

 ponderance of records south of Tweed is entirely due to old-established 

 lines of migration, or to the number of light-vessels on the English coast 



' I am still convinced of the accuracy of my identification of this bird — 

 J. A. H. B. 



