EFFECT OF WINDS ON THE FLIGHT OF BIRDS. 27 



spring, which is just what we should expect, because in the 

 months of April and May we have not much west wind (see 

 Mr. Preston's tables before referred to). 



It may, I believe, be laid down as a law that the direction 

 of the wind is the key to the movements, not only of Gulls, but 

 of all birds which migrate at a low altitude (and especially those 

 which journey by day), such land-birds, for example, as Corvus 

 comix, C. frugilegus, C. monedula, Alauda arvensis, Fringilla 

 coslebs, Sturnus vulgaris, Turdus musicus, Scolopax rusticula, 

 Accipiter nisus, and Falco tinnuncidus. The annexed map will 

 make my meaning more plain, as it shows the wind from the 

 west, the bending outline of our coast, and the course taken 

 by the Gulls. When these Gulls have flown as far as the 

 salt water goes, I believe they generally remain until the 

 wind drops in such estuaries as the Humber-mouth, the 

 Wash, and the mouth of the Thames ; but land-birds, e.g., 

 Crows and Larks, indicated on the map by the larger arrow- 

 heads, go inland, still, in most cases, flying against the wind." 



In my opinion the west winds of autumn indirectly are the 

 cause which brings the Pectoral Sandpiper (Tringa maculata), 

 Sabine's Gull (Xema sabinii), and many other North American 

 birds enumerated in Saunders' "Manual" — especially among 

 the Scolopacidse — to the east coast of the British Isles, 

 instead of landing them in Ireland, which is much nearer 

 to the United States. Or, if Sabine's Gull does occur in 

 Ireland, it is on the east side, as all the records show, where 

 it has a wind to fly against. Certainly, if it were not for 

 the west wind there would not be that annual east-to-west 

 autumnal migration which there is to Norfolk and on the 



* The late Mr. N. F. Hele, writing of the Woodcock in his ''Notes or 

 Jottings about Aldeburgh, Suffolk " (1870), says : "It always appears under 

 the circumstance of a north-west wind. I have not been able to trace its 

 advent at any other time. Living as we do, close to the seaside, we have 

 often the opportunity of observing these birds actually under way from 

 over the sea towards the land. The flight is exceedingly rapid, directly 

 against the wind" (I. c, p. 122). In 1883 I had three or four from light- 

 houses which were killed duriDg westerly or north-westerly winds. In 1884 

 I distinctly noted a flight at Cromer on November 6th ; the wind the day 

 before was south-south-westelry, and the Woodcocks had doubtless arrived 

 in the night. 



