1 9 1 8 . ] Birds of the Isle of May. 253 



by another route should westerly winds prevail during their 

 normal migration-period. 



Thirdly. Species which breed in the far north of both 

 heiuisphereSj such as Lapland Buntings and Shore-Larks, 

 appear in both easterly and westerly winds. 



Fourthly. Observations made on the flight of Homing 

 Pigeons also go to prove this point : for instance, a pigeon- 

 fancier in Kirkcaldy (Fife) told us that when Pigeons were 

 flown from North Berwick to Kirkcaldy, the route taken by 

 the birds varied according to the wind which was blowing at 

 the time. On a perfectly calm day, he had ascertained from 

 observation that the Pigeons flew straiglit from one spot to 

 the other. If the wind were westerly the birds crossed 

 pretty straight over the Firth to the side opposite North 

 Berwick, and then approached Kirkcaldy from the east along 

 the north side of the estuary. If, on the other hand, the 

 wind were easterly, the Pigeons hugged the south side of the 

 Firth and crossed over much farther up, sometimes as high 

 as Aberdour, thus actually approaching Kirkcaldy from the 

 west side. The distance from North Berwick to Kirkcaldy 

 is infinitesimal compared with that traversed by birds during 

 their migration-flights, and if the divergence caused by the 

 varying winds be so great in so small a distance, it is a fair 

 assumption that on a flight of hundreds of miles it will 

 assume very considerable proportions indeed. We have had 

 corroborative evidence from others who fly Homing Pigeons. 



Fifthly. If easterly winds continue over a considerable 

 period birds keep coming in, but the migrants tend to 

 remain on the island and do not pass on until the wind 

 changes to the west, when the island is swept bare almost 

 in a single night. This appears to us to show that the 

 easterly wind is not favourable to the birds' southern 

 journey, but has drifted them across the North Sea, many 

 miles out of their direct route, which they will flud it difficult 

 to regain until the wind changes. 



Sixthly. In westerly winds rushes of birds visit the 

 Liuchiu Islands, oft' the east coast of Asia. 



SBK. X. VOL. VI. T 



