ON TUB MIGRATION OF BIRDS. 267 



this has not, however, been the case at sea stations — that is, light- 

 vessels moored off the coast, at distances varying from five to fiftv 

 miles. Here the stream of migration, so far from showing any abate- 

 ment, has flown steadily on in a full tide : and, if we judge from the 

 well-tilled schedules which have been returned, there has been a con- 

 siderable increase in the visible migration, due perhaps in some measure 

 to increased interest and improved observation. Mr. William Stock, of 

 the Outer Dowsing lightvessel, remarks that he had never before seen so 

 many birds pass that station ; the rush, also, across and past Heligoland in 

 the autumn was enormous. Migration is more marked, as well as concen- 

 trated there, than at any station on the English coast. There was a 

 great movement of various species passing forward on the 6th and 7th of 

 August, and again on the 14th, and more pronounced still on the 21st 

 and 22nd, and on the 20th of August a similar movement was noticed at 

 the Isle of May, at the mouth of the Firth of Forth. It was not, however, 

 until September 21st and the two following days that the first great rush 

 occurred on the English east coast, and a similar great movement or rush 

 is indicated, at the same date, in Mr. Giitke's notes, as well as from the 

 most distant of the lightships. The prevailing winds over the North Sea 

 on September 21st were moderate north-easterly and easterly off the coasts 

 of Denmark and Holland, blowing strong eastei-ly on to the coast north 

 of the Humber, with southerly and south-westerly off the south-east 

 coast, producing cross-currents over the North Sea. Whatever was the 

 impulse, atmospheric or otherwise, which induced such a vast rush of 

 various species at this time, it was one which acted alike, and with pre- 

 cisely the same impulse, on the sea-eagle and the tiny goldcrest. 



The second great rush was on October 12th and 13th, a similar move- 

 ment being recorded at Heligoland. Then, again, from the 27th to the 

 ;!lst, and somewhat less through the first week in November, the passage 

 across Heligoland, as well as the rush on our east coast, was enormous. 

 Speaking of the nights from the 27th to the 31st inclusive, Mr. Giitke 

 says : ' This was the first move by the million ; for four nights there has 

 been a gigantic feathery tide running.' During this time there were 

 variable winds over the North Sea, but generally easterly and south- 

 easterly on the Continent, strong west winds and squalls prevailing 

 generally on November 5th and 6th. 



Again, with the outburst of some severe weather in the first week in 

 December, a considerable local movement is indicated along the coast 

 from north to south, culminating in the enormous rush of snow-buntings 

 into Lincolnshire about the end of the first week in that month. A care- 

 ful perusal of the report will show how generally the rushes across Heli- 

 goland correlate with those on the east coast of England, although not 

 always confined to identical species. 



A somewhat remarkable and very anomalous movement of migrants 

 is recorded from lightvessels off the Lincolnshire and Norfolk coasts in 

 the spring of 1883. In February, March, April, and May, birds passing 

 the Leman and Ower, Llyn Wells, Outer Dowsing, Newarp and the Cockle 

 lightvessels, were, as a rule, coming from easterly and passing in ivesterly 

 directions. The entries show a great immigration of our ordinary autumn 

 migrants from the east in the spring months, and on exactly the same 

 lines and directions as are travelled by the same species in autumn. 

 Had this movement been observed at one station only, we might perhaps 

 have been induced to doubt the accuracy of the return, but the fact of 



