VOL. xin.] ORNITHOLOGICAL NOTES 251 



to us. From an observer who is situated some way to the 

 south of Happisburgh, I learn that October 8th-i2th were 

 days of migration, especially with the Lapwings, which 

 coincides with a very large inrush of this species registered 

 by Mr. Caton-Haigh in north Lincolnshire. On October 8th 

 Dr. B. B. Riviere also remarked Lapwings coasting westwards, 

 and again on the iSth he was witness to a huge passage of 

 this species, in which Starlings and Sky-Larks also participated. 



Allusion has been made to the spring emigration of Rooks, and 

 there was the customary return immigration in October. At 

 that season it is a common event to find a drowned Rook 

 or two lying dead on the shore, but in 191 9 they underwent 

 a disaster of unusual magnitude, of which more presently. 

 It certainly is curious that Rooks and Crows, and smaller birds 

 too, should leave the other side of the North Sea, where they 

 know that they are safe, with the prospect of rough weather, 

 but the migratory instinct which impels them to go forward, 

 is supreme, and at all risks the journey has to be continued. 

 The theory that they start when the weather is fine is not 

 tenable, for foul weather does not spring up at an hour's 

 notice, and on the present occasion it had been going on for 

 some days, therefore the Rooks must have been well aware of 

 the conditions under which they were going to cross the 

 North Sea. If they waited for a favourable day they could 

 easily do the hundred miles or so which lie between Norfolk 

 and Holland in three or four hours, but with bad weather 

 it would naturally take longer, and be far more dangerous. 

 During September Skipper Albert Dawson had some experi- 

 ence with migrants at sea, which although not unusual, may 

 be worth relating. According to my journal there was not 

 much wind, but he reports the weather at sea as having been 

 at the time very hazy. His steam-trawler was about 200 

 miles E.N.E. of the Inner Dowsing light-vessel on September 

 23rd, 24th, and 25th, on which days about a hundred birds 

 settled on the vessel, seeming to Dawson to come from the 

 west. The birds were Linnets, Starlings, Tomtits, Blackcaps 

 (or possibly Great Tits) Pigeons, and others which he did 

 not know. I wish he had brought a few wings back with 

 him. 



The Effect of Wind on Migration. — The more the advent of 

 autumnal flights of migratory birds is studied on the east 

 coast, the more convinced one becomes that wind is a prime 

 agent. There are several factors in birds' movements which 

 are not always taken into consideration, and one is this : 

 there is not infrequently an upper and a lower stratum of 



